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- Torque and HP: A Primer.
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Motor related info...
Torque and Horsepower - A Primer
From Bruce Augenstein (sometime in the 1990s)
There's been a certain amount of discussion, in this and other files, about the concepts of horsepower and torque, how they relate to each other, and how they apply in terms of automobile performance. I have observed that, although nearly everyone participating has a passion for automobiles, there is a huge variance in knowledge. It's clear that a bunch of folks have strong opinions (about this topic, and other things), but that has generally led to more heat than light, if you get my drift :-). I've posted a subset of this note in another string, but felt it deserved to be dealt with as a separate topic. This is meant to be a primer on the subject, which may lead to serious discussion that fleshes out this and other subtopics that will inevitably need to be addressed.
OK. Here's the deal, in moderately plain english.
Force, Work and Time
If you have a one pound weight bolted to the floor, and try to lift it with one pound of force (or 10, or 50 pounds), you will have applied force and exerted energy, but no work will have been done. If you unbolt the weight, and apply a force sufficient to lift the weight one foot, then one foot pound of work will have been done. If that event takes a minute to accomplish, then you will be doing work at the rate of one foot pound per minute. If it takes one second to accomplish the task, then work will be done at the rate of 60 foot pounds per minute, and so on.In order to apply these measurements to automobiles and their performance (whether you're speaking of torque, horsepower, newton meters, watts, or any other terms), you need to address the three variables of force, work and time.
Awhile back, a gentleman by the name of Watt (the same gent who did all that neat stuff with steam engines) made some observations, and concluded that the average horse of the time could lift a 550 pound weight one foot in one second, thereby performing work at the rate of 550 foot pounds per second, or 33,000 foot pounds per minute, for an eight hour shift, more or less. He then published those observations, and stated that 33,000 foot pounds per minute of work was equivalent to the power of one horse, or, one horsepower.
Everybody else said OK. :-)
For purposes of this discussion, we need to measure units of force from rotating objects such as crankshafts, so we'll use terms which define a *twisting* force, such as foot pounds of torque. A foot pound of torque is the twisting force necessary to support a one pound weight on a weightless horizontal bar, one foot from the fulcrum.
Now, it's important to understand that nobody on the planet ever actually measures horsepower from a running engine. What we actually measure (on a dynomometer) is torque, expressed in foot pounds (in the U.S.), and then we *calculate* actual horsepower by converting the twisting force of torque into the work units of horsepower.
Visualize that one pound weight we mentioned, one foot from the fulcrum on its weightless bar. If we rotate that weight for one full revolution against a one pound resistance, we have moved it a total of 6.2832 feet (Pi * a two foot circle), and, incidently, we have done 6.2832 foot pounds of work.
OK. Remember Watt? He said that 33,000 foot pounds of work per minute was equivalent to one horsepower. If we divide the 6.2832 foot pounds of work we've done per revolution of that weight into 33,000 foot pounds, we come up with the fact that one foot pound of torque at 5252 rpm is equal to 33,000 foot pounds per minute of work, and is the equivalent of one horsepower. If we only move that weight at the rate of 2626 rpm, it's the equivalent of 1/2 horsepower (16,500 foot pounds per minute), and so on. Therefore, the following formula applies for calculating horsepower from a torque measurement:
Torque * RPM
Horsepower = ------------
5252
This is not a debatable item. It's the way it's done. Period.
The Case For Torque
Now, what does all this mean in carland?First of all, from a driver's perspective, torque, to use the vernacular, RULES :-). Any given car, in any given gear, will accelerate at a rate that *exactly* matches its torque curve (allowing for increased air and rolling resistance as speeds climb). Another way of saying this is that a car will accelerate hardest at its torque peak in any given gear, and will not accelerate as hard below that peak, or above it. Torque is the only thing that a driver feels, and horsepower is just sort of an esoteric measurement in that context. 300 foot pounds of torque will accelerate you just as hard at 2000 rpm as it would if you were making that torque at 4000 rpm in the same gear, yet, per the formula, the horsepower would be *double* at 4000 rpm. Therefore, horsepower isn't particularly meaningful from a driver's perspective, and the two numbers only get friendly at 5252 rpm, where horsepower and torque always come out the same.
In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm, especially when torque values are also climbing. Horsepower will continue to climb, however, until well past the torque peak, and will continue to rise as engine speed climbs, until the torque curve really begins to plummet, faster than engine rpm is rising. However, as I said, horsepower has nothing to do with what a driver *feels*.
You don't believe all this?
Fine. Take your non turbo car (turbo lag muddles the results) to its torque peak in first gear, and punch it. Notice the belt in the back? Now take it to the power peak, and punch it. Notice that the belt in the back is a bit weaker? Fine. Can we go on, now? :-)
The Case For Horsepower
OK. If torque is so all-fired important, why do we care about horsepower?Because (to quote a friend), "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*.
For an extreme example of this, I'll leave carland for a moment, and describe a waterwheel I got to watch awhile ago. This was a pretty massive wheel (built a couple of hundred years ago), rotating lazily on a shaft which was connected to the works inside a flour mill. Working some things out from what the people in the mill said, I was able to determine that the wheel typically generated about 2600(!) foot pounds of torque. I had clocked its speed, and determined that it was rotating at about 12 rpm. If we hooked that wheel to, say, the drivewheels of a car, that car would go from zero to twelve rpm in a flash, and the waterwheel would hardly notice :-).
On the other hand, twelve rpm of the drivewheels is around one mph for the average car, and, in order to go faster, we'd need to gear it up. To get to 60 mph would require gearing the wheel up enough so that it would be effectively making a little over 43 foot pounds of torque at the output, which is not only a relatively small amount, it's less than what the average car would need in order to actually get to 60. Applying the conversion formula gives us the facts on this. Twelve times twenty six hundred, over five thousand two hundred fifty two gives us:
6 HP.
Oops. Now we see the rest of the story. While it's clearly true that the water wheel can exert a *bunch* of force, its *power* (ability to do work over time) is severely limited.
At The Dragstrip
OK. Back to carland, and some examples of how horsepower makes a major difference in how fast a car can accelerate, in spite of what torque on your backside tells you :-).A very good example would be to compare the current LT1 Corvette with the last of the L98 Vettes, built in 1991. Figures as follows:
Engine Peak HP @ RPM Peak Torque @ RPM
------ ------------- -----------------
L98 250 @ 4000 340 @ 3200
LT1 300 @ 5000 340 @ 3600
The cars are geared identically, and car weights are within a few pounds,
so it's a good comparison.
First, each car will push you back in the seat (the fun factor) with the same authority - at least at or near peak torque in each gear. One will tend to *feel* about as fast as the other to the driver, but the LT1 will actually be significantly faster than the L98, even though it won't pull any harder. If we mess about with the formula, we can begin to discover exactly *why* the LT1 is faster. Here's another slice at that formula:
Horsepower * 5252
Torque = -----------------
RPM
If we plug some numbers in, we can see that the L98 is making 328 foot
pounds of torque at its power peak (250 hp @ 4000), and we can infer that
it cannot be making any more than 263 pound feet of torque at 5000 rpm, or
it would be making more than 250 hp at that engine speed, and would be so
rated. In actuality, the L98 is probably making no more than around 210
pound feet or so at 5000 rpm, and anybody who owns one would shift it at
around 46-4700 rpm, because more torque is available at the drive wheels
in the next gear at that point.
On the other hand, the LT1 is fairly happy making 315 pound feet at 5000 rpm, and is happy right up to its mid 5s redline.
So, in a drag race, the cars would launch more or less together. The L98 might have a slight advantage due to its peak torque occuring a little earlier in the rev range, but that is debatable, since the LT1 has a wider, flatter curve (again pretty much by definition, looking at the figures). From somewhere in the mid range and up, however, the LT1 would begin to pull away. Where the L98 has to shift to second (and throw away torque multiplication for speed), the LT1 still has around another 1000 rpm to go in first, and thus begins to widen its lead, more and more as the speeds climb. As long as the revs are high, the LT1, by definition, has an advantage.
Another example would be the LT1 against the ZR-1. Same deal, only in reverse. The ZR-1 actually pulls a little harder than the LT1, although its torque advantage is softened somewhat by its extra weight. The real advantage, however, is that the ZR-1 has another 1500 rpm in hand at the point where the LT1 has to shift.
There are numerous examples of this phenomenon. The Integra GS-R, for instance, is faster than the garden variety Integra, not because it pulls particularly harder (it doesn't), but because it pulls *longer*. It doesn't feel particularly faster, but it is.
A final example of this requires your imagination. Figure that we can tweak an LT1 engine so that it still makes peak torque of 340 foot pounds at 3600 rpm, but, instead of the curve dropping off to 315 pound feet at 5000, we extend the torque curve so much that it doesn't fall off to 315 pound feet until 15000 rpm. OK, so we'd need to have virtually all the moving parts made out of unobtanium :-), and some sort of turbocharging on demand that would make enough high-rpm boost to keep the curve from falling, but hey, bear with me.
If you raced a stock LT1 with this car, they would launch together, but, somewhere around the 60 foot point, the stocker would begin to fade, and would have to grab second gear shortly thereafter. Not long after that, you'd see in your mirror that the stocker has grabbed third, and not too long after that, it would get fourth, but you'd wouldn't be able to see that due to the distance between you as you crossed the line, *still in first gear*, and pulling like crazy.
I've got a computer simulation that models an LT1 Vette in a quarter mile pass, and it predicts a 13.38 second ET, at 104.5 mph. That's pretty close (actually a tiny bit conservative) to what a stock LT1 can do at 100% air density at a high traction drag strip, being powershifted. However, our modified car, while belting the driver in the back no harder than the stocker (at peak torque) does an 11.96, at 135.1 mph, all in first gear, of course. It doesn't pull any harder, but it sure as hell pulls longer :-). It's also making *900* hp, at 15,000 rpm.
Of course, folks who are knowledgeable about drag racing are now openly snickering, because they've read the preceeding paragraph, and it occurs to them that any self respecting car that can get to 135 mph in a quarter mile will just naturally be doing this in less than ten seconds. Of course that's true, but I remind these same folks that any self-respecting engine that propels a Vette into the nines is also making a whole bunch more than 340 foot pounds of torque.
That does bring up another point, though. Essentially, a more "real" Corvette running 135 mph in a quarter mile (maybe a mega big block) might be making 700-800 foot pounds of torque, and thus it would pull a whole bunch harder than my paper tiger would. It would need slicks and other modifications in order to turn that torque into forward motion, but it would also get from here to way over there a bunch quicker.
On the other hand, as long as we're making quarter mile passes with fantasy engines, if we put a 10.35:1 final-drive gear (3.45 is stock) in our fantasy LT1, with slicks and other chassis mods, we'd be in the nines just as easily as the big block would, and thus save face :-). The mechanical advantage of such a nonsensical rear gear would allow our combination to pull just as hard as the big block, plus we'd get to do all that gear banging and such that real racers do, and finish in fourth gear, as God intends. :-)
The only modification to the preceeding paragraph would be the polar moments of inertia (flywheel effect) argument brought about by such a stiff rear gear, and that argument is outside of the scope of this already massive document. Another time, maybe, if you can stand it :-).
At The Bonneville Salt Flats
Looking at top speed, horsepower wins again, in the sense that making more torque at high rpm means you can use a stiffer gear for any given car speed, and thus have more effective torque *at the drive wheels*.Finally, operating at the power peak means you are doing the absolute best you can at any given car speed, measuring torque at the drive wheels. I know I said that acceleration follows the torque curve in any given gear, but if you factor in gearing vs car speed, the power peak is *it*. An example, yet again, of the LT1 Vette will illustrate this. If you take it up to its torque peak (3600 rpm) in a gear, it will generate some level of torque (340 foot pounds times whatever overall gearing) at the drive wheels, which is the best it will do in that gear (meaning, that's where it is pulling hardest in that gear).
However, if you re-gear the car so it is operating at the power peak (5000 rpm) *at the same car speed*, it will deliver more torque to the drive wheels, because you'll need to gear it up by nearly 39% (5000/3600), while engine torque has only dropped by a little over 7% (315/340). You'll net a 29% gain in drive wheel torque at the power peak vs the torque peak, at a given car speed.
Any other rpm (other than the power peak) at a given car speed will net you a lower torque value at the drive wheels. This would be true of any car on the planet, so, theoretical "best" top speed will always occur when a given vehicle is operating at its power peak.
"Modernizing" The 18th Century
OK. For the final-final point (Really. I Promise.), what if we ditched that water wheel, and bolted an LT1 in its place? Now, no LT1 is going to be making over 2600 foot pounds of torque (except possibly for a single, glorious instant, running on nitromethane), but, assuming we needed 12 rpm for an input to the mill, we could run the LT1 at 5000 rpm (where it's making 315 foot pounds of torque), and gear it down to a 12 rpm output. Result? We'd have over *131,000* foot pounds of torque to play with. We could probably twist the whole flour mill around the input shaft, if we needed to :-).
The Only Thing You Really Need to Know
Repeat after me. "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*." :-)Thanks for your time.
Bruce
But this is not all on the subject. There are other views as well, continue reading...
Setting the Record Straight on Torque and Power
Over the past decade, I have encountered any number of articles, on the Internet, that endeavor to explain torque and power. One of those articles, authored by a fellow named Bruce Augenstein, has appeared on dozens of independent Web sites, and seems to have had a strong influence on the popular understanding of this subject. Regardless of his intentions, his article has promoted several fallacious ideas, along with a dubious overall understanding of the subject. Before we look at what he wrote, it will be helpful for us to begin by identifying specific criteria that are useful in assessing the merit of his (or any other) effort to explain this subject:
- Foremost, the explanation should articulate the essential fact that acceleration at any time is proportional to power, along with the essential fact that the acceleration associated with any specific amount of engine torque, depends on the engine speed.
- Regardless of whether the explanation articulates those essential facts, it must not espouse any fallacious notions that are contrary to those facts.
- If the explanation endeavors to explain any fundamental physical concepts such as torque, work, and power, those explanations should be fundamentally correct.
Before looking at what he wrote, we should also take a quick review of the essential facts. If you turn the crank of a well to lift a 1-lb bucket at a steady rate of 1 ft/min, you are doing work at the rate of 1 ft-lb/min. This is simply the product of the force and the velocity, and turning it around, force is equal to power divided by the (non-zero) velocity. If you substitute that expression for force into the familiar equation that relates force, mass and acceleration, you get:
acceleration = power / (mass x velocity)
If you multiply the product of torque and rotational speed by twice pi, you effectively translate that product to the equivalent product of force and linear velocity, i.e., you calculate the power.
acceleration = engine_torque x 2 x pi x engine_speed / (velocity x mass)
Hence, given the vehicular velocity that is applicable to some point in time, the acceleration that you get, for a given amount of engine torque and a given mass, depends on the engine speed. Of course, if the ratio of engine speed to vehicle speed is given, as it effectively is while the gear ratio is held constant, acceleration will then vary according to the engine torque. Here we go:
“First of all, from a driver's perspective, torque, to use the vernacular, RULES :-). Any given car, in any given gear, will accelerate at a rate that *exactly* matches its torque curve … Torque is the only thing that a driver feels, and horsepower is just sort of an esoteric measurement in that context. 300 foot pounds of torque will accelerate you just as hard at 2000 rpm as it would … at 4000 rpm in the same gear, yet … the horsepower would be *double* at 4000 rpm. Therefore, horsepower isn't particularly meaningful from a driver's perspective, and the two numbers only get friendly at 5252 rpm, where horsepower and torque always come out the same.
In contrast to a torque curve (and the matching pushback into your seat), horsepower rises rapidly with rpm. ... However, as I said, horsepower has nothing to do with what a driver *feels*.
You don't believe all this? Fine. Take your non turbo car (turbo lag muddles the results) to its torque peak in first gear, and punch it. Notice the belt in the back? Now take it to the power peak, and punch it. Notice that the belt in the back is a bit weaker? Fine. Can we go on, now? :-)”
It is true that 300 lb-ft of torque will yield the same acceleration at 2000 rpm as it will at 4000 rpm in the same gear, and the power will of course be double at 4000 rpm. However, the force that the driver feels at any instant is proportional to the driver’s acceleration, which is the same as the vehicular acceleration, and because vehicular acceleration is always proportional to power, it is obvious that the force felt by the driver at any instant is proportional to power. Yet, he asserts that “torque is the only thing that the driver feels”, that “horsepower is just sort of an esoteric measurement”, and that “horsepower has nothing to do with what a driver *feels*”. No honest, unbiased assessment of what he wrote could deny that the bulk and gist of it is simply nonsense. The only place where what he was thinking is uncertain, is where he says that torque and horsepower “get friendly at 5252 rpm”. It’s anyone’s guess what he was thinking when he wrote that, but the number 5252 is merely an artifact of using English units of measure for torque and power.
He argues that power is meaningless since according to him, the acceleration that you get for a given amount of engine torque is the same no matter the engine speed. That is what he encourages the reader to infer from the fact that, in a given gear, the acceleration that you get for a specific amount of engine torque does not vary. That is simply a ruse. The pertinent facts are that wheel torque at a given wheel speed depends equally on engine torque and engine speed, and that the acceleration associated with a given amount of engine torque always depends on the engine speed. These highly pertinent facts can be understood via the fact that power is the same at both locations (ignoring friction), and via the fact that power is essentially equal to the product of torque and rotational speed.
That excerpt came from his section titled, “The Case For Torque”, which took us right to the heart of the problem with his understanding of this subject. Near the beginning of his article, the section titled “Force, Work and Time”, offers this explanation of power:
“If you have a one pound weight bolted to the floor, and try to lift it with one pound of force (or 10, or 50 pounds), you will have applied force and exerted energy, but no work will have been done. If you unbolt the weight, and apply a force sufficient to lift the weight one foot, then one foot pound of work will have been done. If that event takes a minute to accomplish, then you will be doing work at the rate of one foot pound per minute.”
This explanation of power muddles the connection between power and acceleration, because it doesn’t reveal the meaning of instantaneous power, as distinct from that of average power, which has no simple relationship to instantaneous acceleration. Additionally, energy isn’t spent unless work is performed, and while a minimum force is required to overcome the force of gravity and move the weight at all, it makes no sense to talk of the force sufficient to move an object a specific distance. These misunderstandings clearly reveal a lack of basic knowledge, but they are innocent, and do not suggest any dubious agenda. However, smack dab in the middle of his theoretical explanation of power, he spiced things up a bit:
“Now, it's important to understand that nobody on the planet ever actually measures horsepower from a running engine. What we actually measure (on a dynomometer) is torque, expressed in foot pounds (in the U.S.), and then we *calculate* actual horsepower by converting the twisting force of torque into the work units of horsepower.”
Does this mean that power cannot be measured except by first measuring torque? Why else would this be “important to understand”, or worth mentioning? The notion, that power is somehow less real than torque, is easily identifiable as a theme of the article. Yet, it has no meaning or interpretation that can be confirmed experimentally, and as far as the orthodoxy and methodology of empirical science is concerned, notions of that sort are meaningless. This criticism would be no less valid even if it were true that power is only ever deduced by measuring torque and rotational speed. Of course, with inertial dynamometers, you can deduce power from the drum’s angular acceleration and its inertial moment, without measuring torque. For that matter, if you were to apply an engine to the task of lifting an elevator car and you inserted a continuously variable transmission between them to allow you to stabilize the speed of both the engine and the elevator car at any desired engine speed, you would then have a brake dynamometer of sorts. You would deduce power by multiplying the elevator’s steady velocity by its weight (minus the counter-weight), and as with brake dynamometers in general, that measurement will be unaffected by the engine’s inertial resistance to acceleration.
Next came the section I discussed first, and then a section titled, “The Case For Horsepower”:
“OK. If torque is so all-fired important, why do we care about horsepower?
Because (to quote a friend), "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*.
For an extreme example of this, I'll … describe a waterwheel I got to watch awhile ago. This was a pretty massive wheel …, rotating lazily on a shaft which was connected to the works inside a flour mill. … the wheel typically generated about 2600(!) foot pounds of torque. …it was rotating at about 12 rpm. If we hooked that wheel to, say, the drivewheels of a car, that car would go from zero to twelve rpm in a flash, and the waterwheel would hardly notice :-). … twelve rpm of the drivewheels is around one mph for the average car, and, in order to go faster, we'd need to gear it up. To get to 60 mph would require gearing the wheel up enough so that it would be effectively making a little over 43 foot pounds of torque at the output, which is not only a relatively small amount, it's less than what the average car would need in order to actually get to 60. Applying the conversion formula gives us the facts on this. Twelve times twenty six hundred, over five thousand two hundred fifty two gives us: 6 HP.
Oops. Now we see the rest of the story. While it's clearly true that the water wheel can exert a *bunch* of force, its *power* (ability to do work over time) is severely limited. ”
Even though there are no errors per se in this, I still find it annoying. He started by saying that we care about horsepower because making torque at higher rpm means that you can take advantage of gearing. The gist of the anecdote is that even though the torque of the waterwheel itself is substantial, if gearing is applied to increase the output speed, the torque is reduced accordingly. He didn’t say anything about why that happens. He produced a value for the output torque, without any explanation of how it was calculated. He calculated the power, but he did not mention that power, being the same at the output as it is at the input, explains why the output torque must decrease in order to compensate for the increase in output speed. At the end, the point of this anecdote seemed to be to reiterate the fact that torque by itself doesn’t determine the capacity to perform work over time. The formula that you use to calculate power from torque and rotational speed tells you that, and although that is certainly relevant, that fact by itself doesn’t shed much light on the connection between power and acceleration.
Next came the long section titled, “At the Dragstrip”, the essence of which is:
“… some examples of how horsepower makes a major difference in how fast a car can accelerate, in spite of what torque on your backside tells you :-). A very good example would be to compare the current LT1 Corvette with the last of the L98 Vettes, built in 1991. … The cars are geared identically …. First, each car will push you back in the seat … with the same authority - at least at or near peak torque in each gear. One will tend to *feel* about as fast as the other to the driver, but the LT1 will … be significantly faster than the L98, even though it won't pull any harder. …. Where the L98 has to shift to second (and throw away torque multiplication for speed), the LT1 still has around another 1000 rpm to go in first, and thus begins to widen its lead ...
Another example would be the LT1 against the ZR-1. Same deal, only in reverse. The ZR-1 actually pulls a little harder than the LT1... The real advantage, however, is that the ZR-1 has another 1500 rpm in hand at the point where the LT1 has to shift….There are numerous examples of this phenomenon. The Integra GS-R, for instance, is faster than the garden variety Integra, not because it pulls particularly harder (it doesn't), but because it pulls *longer*...”
In this section, he argues that greater power can yet be advantageous because it allows the driver to wait longer before shifting to the next gear. He repeatedly asserts that greater power allows you to pull “longer”, but not “harder”. He consistently applied the constraint that the two cars that he was comparing in order to illustrate what he was trying to say, share identical transmissions and identical overall gear ratios. That constraint obscures the pertinent fact that the car with greater peak power may well exhibit greater peak wheel torque in each individual gear, even if its peak engine torque is less than that of the other vehicle. This section, which accounts for nearly half of the article, mistakenly assumes that the significance of power can be understood and explained by considering only the peak power. It then compounds that mistake by giving a ridiculous, bogus explanation of the advantage of greater peak power.
Toward the end of the article, in the section titled, “At The Bonneville Salt Flats”, he talked about the fact that the power peak is the best engine speed (regardless of the vehicle speed):
“I know I said that acceleration follows the torque curve in any given gear, but if you factor in gearing vs car speed, the power peak is *it*. An example, yet again, of the LT1 Vette will illustrate this. If you take it up to its torque peak (3600 rpm) in a gear … However, if you re-gear the car so it is operating at the power peak (5000 rpm) *at the same car speed*, it will deliver more torque to the drive wheels, because you'll need to gear it up by nearly 39% (5000/3600), while engine torque has only dropped by a little over 7% (315/340). You'll net a 29% gain in drive wheel torque at the power peak vs the torque peak, at a given car speed. ”
Note first that it isn’t generally necessary to re-gear a car in order to select an engine speed at or near the power peak in lieu of the torque peak. Low vehicle speed, where 1st gear is the gear that offers the greatest power, is the exception of course.
That was the closest that he ever got to saying that acceleration is proportional to power. It is in the vicinity of the target, but because it deals specifically with the power peak and does not say plainly that acceleration is proportional to power, it doesn’t hit the bulls-eye. Without a clear understanding of the fact that acceleration is always proportional to power, there is no understanding of why optimal shifting consists of always selecting the gear that yields the greatest power. Note also that even though his calculation correctly implies that wheel torque is proportional to the product of engine torque and engine speed (and thus to power), he never plainly said so, and he never said anything about why it is true.
For his summary, he chose to repeat his perspective on why power is relevant:
“The Only Thing You Really Need to Know
Repeat after me. "It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*." :-)”
This is not particularly conducive to an insightful understanding of why power and engine speed matter. Engine torque reveals the amount of work performed over any specific interval of crankshaft rotation, whereas acceleration at any time is proportional to the rate at which work is being performed, which rate depends as much on engine speed as it depends on engine torque.
The facts that are pertinent to a proper understanding of this subject are conspicuously missing from Augenstein’s article, having been replaced by bogus ideas. Instead of saying plainly that acceleration is proportional to power, he defiantly asserted that only engine torque has anything to do with what a driver feels. He made audacious claims about the measurability of power, and his explanations of the significance of power, were bogus. There is very little in his article that qualifies as a usefully correct explanation of anything, and most of what he espouses is bogus.
And one more...
Plato and Socrates Discuss Torque, Power and Acceleration
Plato: Dude, nice toga. Say, I’ve just been reading up on torque and power. Torque, it seems, is the rotational equivalent of force in straight-line motion.
Socrates: To fully appreciate what that means and get us off on a solid footing, let’s start with a quick look at the familiar equation: F = M x A. This equation tells us that whenever an object’s present velocity is changing, the acceleration is given by the ratio of force to mass. Manifestly, the greater an object’s mass, the greater the force needed to yield a specified amount of acceleration. Mass also determines how much kinetic energy an object contains when it is moving at a given velocity. In rotational motion, that familiar equation is replaced by a similar equation: Torque = Moment-of-Inertia x Angular Acceleration. The moment of inertia determines how much torque is needed to yield a given amount of angular acceleration, as well as how much kinetic energy an object contains when spinning at a given angular velocity. When an ice skater in a spin brings his or her arms in closer to the torso, there is no loss of kinetic energy, and the observed increase in angular velocity reveals that the moment of inertia has been made smaller.
Plato: To find the torque associated with a straight-line force, you multiply the force by the length of the lever arm, which is always measured along a line of direction that is square to the direction of the force. Whenever I tighten a bolt, if I vary the length of the lever arm, the force that I sense in my hand and arm will change, yet the torque doesn’t change unless the amount of friction in the threads changes. Whenever I think about overcoming friction, I think about work and power.
Socrates: To find the work associated with any steady force, you multiply the force by the distance covered. Whereas work is cumulative over time and distance, power is the measure of how quickly work is being performed, instantaneously in time. Work and energy are truly the same concept, so the measure of how quickly work is being performed, is also the measure of how quickly energy is being spent. If you turn the crank of a well to lift a 1-lb bucket at a steady rate of 1 ft/min, you are doing work at the steady rate of 1 ft-lb/min, which is simply the product of the force and the velocity. If the radius of the spool is 1 ft, then the torque applied to the crank by the 1-lb bucket, will be 1 lb-ft. In each complete rotation of the crank, the bucket will move a distance equal to the radius of the spool multiplied by twice pi. It follows that the work associated with a specific amount of torque, for one complete rotation, may be found by multiplying the torque by twice pi. The calculation of power from torque and rotational speed is similar. The following chart summarizes:
|
straight-line motion |
rotational motion |
work |
force x distance |
torque x number of rotations x 2 x pi |
power |
force x velocity |
torque x angular velocity x 2 x pi |
The expression for power in rotational motion reveals that you always multiply by the same constant value (2 x pi) to calculate power from the product of torque and angular velocity. Note, though, that this assumes that angular velocity is measured in complete rotations per unit of time. You could just as easily measure angular velocity using a smaller angular distance, such that you would have to multiply that smaller angular distance by twice pi in order to yield one complete rotation. If you measured angular velocity using that smaller angular distance (which is known as a “radian”), the expression for power would be simply the product of torque and angular velocity, i.e., you would not multiply by twice pi to calculate power. Hence, the business of multiplying by twice pi is equivalent in effect to converting from one unit of measure to another, and it is correct to say that power is simply equal to the product of torque and angular velocity.
Plato: If the bucket is raised at steady velocity, its kinetic energy will be steady. Only its potential energy will be changing, and the power will be simply the static weight of the bucket multiplied by the steady velocity. It is easy enough to measure instantaneous velocity when the velocity is steady, but in real-world scenarios, doesn’t it get more complicated?
Socrates: A common approach to measuring the power of an engine is to use a regulated brake to hold the engine steady at the desired speed. You have to measure the force that resists the pull of the engine on the brake, so that you can deduce the engine torque from that force and from the lever arm, which you also have to figure out. And, of course, you have to measure the engine speed. Dynamometers of this sort are known as “brake dynamometers”. Conceptually, you could implement a brake dynamometer of sorts by applying the engine to the task of lifting an elevator car, using a continuously variable transmission in the coupling. The CVT would allow you to stabilize the speed of both the engine and the elevator car at any desired engine speed. To deduce power, you would multiply the elevator’s steady velocity by its weight, and as with brake dynamometers in general, those measurements would be unaffected by the engine’s inertial moment. The other common approach is to hitch the engine to a massive drum that spins freely. As long as the increase in the kinetic energy of the drum is the only energy sink, the power will be given by the instantaneous rate of increase of the drum’s kinetic energy, which can be deduced from the drum’s moment of inertia and its instantaneous angular acceleration. Dynamometers of this type are known as “inertial dynamometers”. The angular acceleration can be measured with the help of an accelerometer, or deduced from closely spaced measurements of time and angular distance. The drum’s moment of inertia can be measured separately, or calculated from its dimensions and the density of its substance. The increase in the kinetic energy of the engine itself is an energy sink. The measurements are influenced to a degree by the engine’s moment of inertia, and they reveal, to a degree, the ability of the engine to quickly increase its work output. As such, measurements taken on an inertial dynamometer give a more realistic picture of an engine’s actual performance on the road. For purposes of ordinary performance tuning on a test bench, that sort of accuracy isn’t particularly beneficial, whereas the ability to keep the engine running steadily for extended periods can be beneficial.
Plato: I read somewhere that to measure power, you measure torque and then you deduce power from torque. That supposedly demonstrates that power is just an abstraction of torque.
Socrates: Clearly, there are various ways to measure power independently of torque. Moreover, the notion, that power is less real than torque, has no meaning or interpretation that is capable of being confirmed experimentally. As far as the orthodoxy and methodology of empirical science is concerned, notions of that sort are meaningless.
Plato: I should be able to measure the power of my mare, by measuring how quickly she is able to lift a large bucket of water from my well. If I adjust the amount of water such that the velocity is steady, the actual force will be equal to the weight of the bucket. That way, I won’t have to measure the actual strain in the rope, and of course, it will be easier to measure the velocity.
Socrates: In the future, a fellow by the name of James Watt will determine that his horse is able to perform work at an ongoing, instantaneous rate of 33,000 foot-pounds of work per minute. If you measure torque in lb-ft and rotational speed in rpm, and you want to express the power in hp, you can use the conversion factor: 1 hp = 33,000 ft-lb/min. The value of twice pi is 6.283, and that divided by 33,000 is about 1/5252. So, as long as torque is measured in lb-ft, rotational speed is measured in rpm, and you want to express the power in hp, you can take a short cut and divide the product of torque and rotational speed by 5252.
Plato: Does that mean that torque and power are equivalent at 5252 rpm?
Socrates: Nope. Torque and power are distinct properties, with each being analytically related to acceleration in its own special way. The value 5252 is merely an artifact of the English system of measure, and that value is not the least bit special if another system of measure is used. In most of the world, torque is expressed in Newton-meters (N-m), and power is expressed in Watts or kilowatts (kW), which we use for electrical power. The engine speed where torque in lb-ft and power in hp coincidentally take on the same numerical value, happens to fall within the operating range of most engines, so on dynamometer plots, it is convenient to use a single number scale for both torque in lb-ft and power in hp. When that is done, the two curves will cross at 5252 rpm.
Plato: But, it seems that torque should determine acceleration, so why does power matter?
Socrates: Power matters because at any point in time, acceleration is proportional to the rate at which the engine is performing work. Engine torque tells you how much work is performed over any specific interval of crankshaft rotation, but does not tell you how quickly the work is being performed. It is of course possible to deduce acceleration from the engine torque using other information such as the overall gear ratio and wheel diameter, but that doesn’t change the pertinent and useful fact that at any point in time, acceleration is proportional to power. Recall that power is equal to the product of force and velocity. If you turn that around, it says that force is equal to power divided by the (non-zero) velocity. If you substitute that expression for force into the familiar equation that relates force, mass, and acceleration, you get this:
acceleration = power / (mass x velocity) =>
acceleration = engine_torque x 2 x pi x engine_speed / (velocity x mass)
Hence, given the vehicular velocity that is applicable to some point in time, the acceleration that you get, for a given amount of engine torque and a given mass, depends on the engine speed. Of course, if the ratio of engine speed to vehicle speed is given, as it effectively is while the gear ratio is held constant, acceleration will then vary according to the engine torque. (Note that if you plug a set of values into that equation to calculate acceleration, in order to get proper units of measure for acceleration, you need to use lbf instead of lb for the force component of the torque. 1 lbf is the force of gravity on 1 lb of mass: 1 lbf = 1 lb x 32.2 ft/s^2 = 32.2 ft-lb/s^2 = 4.45 N.)
Plato: But, if acceleration is proportional to power, why does acceleration track with the engine torque curve as the engine speed and the vehicle speed increase in a given gear?
Socrates: The perception of a contradiction, between the fact that wheel torque tracks with the engine torque while the gear ratio remains fixed, and the fact that acceleration is proportional to power, is a false perception. The equations reveal that the proportionality between acceleration and power is different at different vehicle speeds. The acceleration that you get for a given amount of power decreases as the vehicle speed increases, yet, at any point in time, acceleration is proportional to power, and depends as much on engine speed as on engine torque.
Plato: What does this mean from the perspective of gear selection strategy?
Socrates: Whenever you change gears, as long as you are quick to avoid any significant loss in vehicle speed during the up-shift, the proportionality between power and acceleration will be steady across the up-shift. Hence, in order for acceleration to be steady across the up-shift, power must be steady across the up-shift, which means that the engine torque must increase to compensate for the drop in engine speed. If the throttle is held open so that actual power follows the engine’s power curve, the engine speed must transition between two equal-power points on opposite sides of the power peak. Note that shifting such that power will be steady across the up-shift, and shifting such that you are always using the gear that yields the greatest power, are two different ways to describe the same optimal strategy.
Plato: What would happen if the engine torque were to be held steady across the up-shift, i.e., you kept the engine speed within the flat region of the engine torque curve?
Socrates: The acceleration would drop abruptly at the up-shift, matching the drop in engine speed. Let’s look at it another way, and let’s take a quick side trip that may help to put the significance of power into better perspective. In an electrical transformer, any increase in voltage between the primary and the secondary windings, must be accompanied by a compensating decrease in current. Power is equal to the product of voltage and current, and as the saying goes, “power in is power out”. That saying applies as well to the physics of mechanical motion. Except for the energy losses due to friction, the product of torque and rotational speed will be the same at the wheel as it is at the engine, and as it is anywhere else that you measure it along the drive train. You want the wheel torque to be steady across the up-shift, and since the wheel speed will also be steady at the up-shift, the product of torque and rotational speed will be steady at the up-shift, not only at the wheel, but at the engine as well. That, of course, means that the engine torque must increase to compensate for the drop in engine speed.
Plato: Okay, but given two vehicles that are identical except for the engines, the one with the greater peak engine torque will still exhibit greater peak acceleration in each gear, right?
Socrates: If the vehicle with greater peak power is allowed to use a different final drive ratio, then by shifting its engine torque peak to lower vehicle speed, the corresponding wheel torque will increase. Thus, the vehicle with greater peak power may exhibit greater peak acceleration in each gear, even if its peak engine torque is less than that of the other vehicle.
Plato: Well, there are still certain benefits to emphasizing torque in lieu of power, aren’t there?
Socrates: Certain effects, such as improved acceleration from a full stop and less frequent shifting, are the result of a comparatively flat, uniform spread of engine output, starting at comparatively low engine speed. It makes perfect sense to attribute such effects to a de-emphasis on peak power. However, logically speaking, torque and power are not opposites, and it does not follow from the fact that you have de-emphasized peak power, that you have emphasized torque. Of course, if there exists some other justification for the practice of equating the engine’s low-speed performance to torque, that will also constitute justification for equating a de-emphasis on peak power to an emphasis on torque, never mind that torque and power are not opposites. At the wheel, the affinity between low rotational speed and torque is quite genuine, owing to the fact that the transmission is used to exchange rotational speed for torque. But this effect does not apply to the engine. The practice, of equating engine performance at low and moderate engine speed exclusively to torque, seems to derive essentially from the fact that the peak engine torque occurs at a lower engine speed than does the peak power. This seems a weak justification when you consider that the peak engine torque reveals the engine performance accurately at only a single engine speed. That engine speed is often above the midpoint of the engine’s operating range, and no matter how low the actual engine speed, the actual performance depends partly on the engine speed, and is fully revealed by the actual power.
Plato: What else?
Socrates: Many people seem to believe that the full explanation, for why longer stroke generally means improved low-end performance, is simply that by increasing the effective lever arm (the crank throw distance is one-half of the stroke distance), you increase the torque. For whatever reason, they don’t realize that if it were that simple, the improvement in engine torque would be uniform over the operating range, which would not explain why the performance improvement is specific to low engine speed. They have somehow gotten the idea that any change, that directly improves engine torque, will automatically favor lower engine speed. Clearly, it isn’t that simple. If you increase the stroke while keeping the volume displacement constant, the piston surface area will decrease, which will nullify the effect of the increased lever arm, since the force depends on the surface area of the piston face. Engine torque corresponds to the amount of energy spent over any specific interval of crankshaft rotation, and that amount of energy depends on the amount of oxygen used. It follows that the variation in engine torque with engine speed reveals the variation in the amount of air captured per individual intake stroke. Cylinder shape interacts with the duration of the intake stroke to influence the amount of air that is captured on the intake stroke. When the cylinder is made long and skinny, the effect is to increase the amount of air captured at low engine speed, and to decrease the amount of air captured at high engine speed. Note also that if the relationship between stroke and torque were as direct as the naïve explanation suggests, you could get free energy just by making the cylinder long and skinny.
Plato: I need to go get measured for a new toga, but before I run along, I’d like to know what you think about the various claims that engine torque is the true indicator of engine performance.
Socrates: Those sorts of claims have to be interpreted to mean that you are always supposed to get the same acceleration for a given amount of engine torque, no matter the engine speed at which that much engine torque is delivered. There simply is no other meaningful, tangible interpretation of those claims. Yet, as we have already seen, wheel torque depends just as much on engine speed as it does on engine torque. Anyone who is not convinced of that, need only discover for themselves that at any of the various vehicle speeds where the transmission will permit you to choose between two equal-torque points on opposite sides of the torque peak, the acceleration will be dramatically greater in the lower of the two gears. It is logically dubious to infer, from the fact that the peak power does a poor job of revealing the engine’s performance at low and moderate engine speeds, that torque is the true indicator of engine performance.
OK Bruce, if you are still out there. It's your turn.
-Brad
I tore apart a '66 327/300hp engine that had been run 100,000 miles on unleaded gas. The head shop said there was no damage because of it. Attached are some snippets from old VetteNet postings and private email relating to leaded gas and octane boosters. They are taken out of context and not arranged in any order. -- Greg ---------------------------------------------------------------------- Private Email from Jim Lockwood I've looked at this same problem for the last few years. My first choice is to find a source of leaded gas with at least 1 gm/gal of lead. For a while, this will continue to be an option, but the handwriting is on the wall....all lead usage will eventually cease. For now, though, my choice of lead sources would be racing gas. The formulation we run in the RPO '57 race car has 8 gm/gal of lead even today. So you could cut it approximately 8:1 with street gas and still end up with your 1 gm/gal minimum. The cost of racing gas, though is around $4.00/gal. So my second choice, and really I think the correct choice, is to rework the heads to tolerate unleaded gas. The best info I've found indicates that the head itself must be modified. Simply installing hardened valves isn't an answer because it is the soft iron head that deteriorates, not the valve. The rework involves milling a groove around the exhaust valve area such that a hardened ring can be pressed in as the new valve seat. The one down side to doing this that I know of is that some older heads do not have enough metal around the valve seat and the milling operation can penetrate the water jacket. Doing so, ruins the head. I've heard of this happening only on heads manufactured in the '50s (unfortunately, I have no fewer than three '50s era cars that need this work :-( ). I haven't heard of any problem with heads manufactured in the '60s. An alternative, if you don't mind the loss of originality, would be to find some '71 or later heads and use them. Starting in '71, all GM engine heads had hardened valve seats and coudl withstand unleaded gas. This is likely to be the simplest way to get a long term solution to the problem. If you elect to take this route, though, you should still retain the original heads. Someday you may want to use them or maybe sell the car to someone who is a bug on originality. ---------------------------------------------------------------------- Private Email from Jim Lockwood I realize I didn't answer one of your other questions: > When makng it high performance, i.e. higher compression pistons, > what are people doing ? Lead additives? Airplace fuel? Octane boosters? I'm not convinced that the Octane boosters do much. I ran 104 Octane Boost a few years ago when I drove my '63 to Bloomington. At every fillup, I added a can. The *only* effect was that the deposits on the plugs turned yellow. The engine still knocked and pinged just as badly as when I hadn't been using the Octane boost product. A fair strategy today might be to go with relatively lower compression pistons (like I did with my '60), and diddle around with the cam and heads to get a free breathing engine. The high compression definitely would be a Good Thing, but you can compensate for its loss in other areas and then you don't need hi Octane gas. For what it's worth, with 9.5:1 pistons, I can run 89 octane gas and the '60 doesn't knock at all. ---------------------------------------------------------------------- Roger A. Goff > (To the person saying he was looking for an older Vette.) > When dad restored our 1960, he had a local engine builder convert it for > unleaded gas. That might be the way for you to go. Hmmm. Let me expand on Joe's comment a little. You don't really convert and engine to burning unleaded gas. What you do is enable the burning of unleaded gas. This is accomplished by putting hardened valve seats and hardened valves into the heads. To really convert an engine to unleaded gas, to me, would mean doing the above plus adding a catalytic converter and other pollution control stuff. I agree that you should enable the use of unleaded gas because it's the only pumpable premium that I know of (other than those of us who've figured out where we can buy AV gas for competition, etc.). ---------------------------------------------------------------------- Jim Lockwood Starting in '71 Corvettes came with hardened valve seats and could run safely on unleaded gas. If you are looking for a driver and aren't inclined to do the surgery necessary on a pre-71 motor to make it run on unleaded safely, then a 71 or later would be a good choice. ---------------------------------------------------------------------- Geoff Swavley University of New South Wales We still have leaded petrol at every garage, therefore 60-70 model engines just love Australia. ---------------------------------------------------------------------- Jim Lockwood A compelling advantage to running r**ing fuel, especially in older cars (for purposes of discussion older == pre 71 GM) that need lead for valve seat protection. At least one formulation of r**ing gas I've seen locally has 8 gm/gal of lead. Contrast that to a generally accepted minimum needed value of 1gm/gal to prevent valve seat wear and it's clear that r**cing gas will get the job done. As to the viability of octane boosters.....my only data point is with the 104 brand of octane booster. When I drove my '63 roadster to Bloomington a few years ago, I packed a case of this stuff and dumped in a can each time I stopped to fill up. Although it turned the plugs yellow, I couldn't tell that it made any difference on the 10.5:1 327.....it still knocked miserably under load. If r**cing gas was convenient (note that I didn't say cheap....it isn't. Out here it's around $4.00/gal.) to buy, I'd mix it with pump gas in a ratio of 8:1 (to keep my 1gm/gal of lead) and run it in my old iron. ---------------------------------------------------------------------- Lloyd Johnson Someone asked about racing gas vs. octane booster so I thought I would give you my experiences with the subject. I drove a Corvette with 11.0:1 compression on the street and in SCCA autocrosses and hill climbs way back when 100+ octane gasoline was still available from the pump at your neighborhood filling station. Over the years the quality of the available pump gas degraded and I was forced to use octane booster. I would add 1 can of 104+ octane booster to a tank of unleaded premium (18 gal.). This worked pretty good for street driving but I could detect some audible detonation under heavy acceleration in competition. I decided it was worth the possible engine damage to continue to run the mixture since most of the miles I put on the car were driving to work and I only competed with it 2 or three times a month. Racing fuel was much more expensive and not redily available. This didn't cause any problem for about 3 years. Finally the inevitable happened and I burned a piston during an autocross due to excessive detonation. It was no big deal, the only work that was required was a new piston, a rebalance, and removal and installation of the unit from the car. There was absolutely no damage to the valves, valve seats, or valve guides. I did decided, however, that the time had come to start using higher octane fuel and to limit the miles I put on the car through street driving. I used 100 octane aviation gas for a while because it was available at the local airport at the time and was about 1/2 the price of racing gas. The av-gas worked satisfactorily and never gave me a problem. Eventually the law changed and I could no longer purchase av-gas from the airport and I was forced to further limit the street miles I put on the car and run racing gas. Some gas companies, Union 76 comes to mind, still sell 100 octane unleaded. I have used this when I could find it and it worked fine also. Most of the time I use a mixture of 3/4 unleaded 93 octane pump gas amd 1/4 114 octane racing gas. There are some advantages to running the lowest octane gas required to keep the engine from detonating. First is cost, racing gas costs $4-5 per gallon depending on the octane rating. Pump gas is only $1.25. Secondly, contrary to what most people believe, higher octane gas does not in itself give you more horsepower. It allows you to produce more power from an engine by increasing the compression ratio limit before you reach detonation. The higher octane fuel actually burns more slowly and produces less energy to be turned into power than the lower octane fuel. I'll probably hear a lot of static from people that don't belive this but that's O.K. Use what you think is best and I'll beat you to the finish line. ---------------------------------------------------------------------- John R. Lupien How much of which kind of lead additive did you add to what grade of gas? I have used some of the "RealLead" additive in my air-coled flat-four, with good results. I added it to 94 octane Sonoco, at about the recommended mix, and got a noticeable improvement in low-rev on-throttle performance. > Am I imaging things, or is this a benefit of the lead additives? If you have a high-compression (and maybe high-temperature) engine, this is precisely the kind of effect that the high-octane leaded gas was supposed to have. ---------------------------------------------------------------------- Jim Lockwood In '71 GM dropped the compression ratios of all their engines and made them compatible with unleaded fuel. Some power loss and performance loss resulted, as you'd imagine. ---------------------------------------------------------------------- Roger A. Goff I believe '75 is the first year for emissions controls, of any variety, on a 'vette. But the '74 certainly did not have a catalytic converter which was the big horsepower killing device. What you were seeing in the period from '72 through '75, was a decrease in the compression ratio of the engines to accomodate the lower octane fuels and attempt to improve fuel economy. ---------------------------------------------------------------------- Phil Gunsul 1969-71 had an Octane Adjustment Unit and staring in '70 there was a relay on the trans to control the spark. 1971 saw a drop in compression ratios from the '70 low of 10.25:1 to the to the '71 HIGHEST ratio of 9:1, with a drop of about 30 h.p. on comparable engines. ---------------------------------------------------------------------- Dave Bright > What advantage is there to using something like Sunoco r*cing fuel > versus using less expensive octane boosters to ordinary premium pump > gasoline ? > > Does the racing fuel have other components? Do the octane boosters > not work very well ?? I'm sure you'll get different answers here and it'll also depend on what year vette you are talking about. But on late model vettes I'll say this. Most of what I have read is that you don't need to put in any higher octane then what the manufacture recommends. That higher octane then what is recommended won't make any difference in performance. Well I for one believe in putting the highest octane I can get which is Sunoco 260. For the following reasons, I believe the higher octane gas will give you a little better performance. I believe the higher octane gas will run cleaner and overall a better gasoline than the lower octanes. For the amount I drive the vette cost difference isn't really that bad. I suppose someone who drives a lot the cost can be a major difference. One thing to be aware of is that you can, on the newer model vettes, put in to high of an octane. One thing the computer does when you first start your car each time is adjust the timing of the engine to where it starts to ping. It gives the computer a threshold to work from base on what type of gas you are using. The car is design to run on lower octane gas and to adjust the timing accordingly to keep it from pinging. So if you put in a VERY high octane gas in the car the computer can't find that upper limit where the car starts to ping. The computer now thinks there is a problem with the car and will set some error code (I don't remember which one). This can drive a you and the mechanic crazy! Put in whatever you think is best, gas is like oil. Some people will swear by synthetics and others say just put in the .89 cent stuff and change it every 3000 miles. ---------------------------------------------------------------------- Rob Loszewski > please cc me your opinions on whether it is damaging > to a TPI motor to run 87 octane in it for let's say, > 75% of its miles. will it do anything other than > reduce power? let's assume it is a "good quality" > 87 octane, passes BMW gas test, or whatever one you want. I wouldn't suggest using a low octane fuel in an engine with TPI. Lower octane fuels have a tendency to carry more particulate contamination than the more expensive ones and the fuel injectors on TPI systems are of poor quality and clog easily. Also, an engine with TPI is categorized as a high output engine. High output engines should at least receive 91 octane in order to extract optimum performance out of them. ---------------------------------------------------------------------- Tony Ozzello when I got my 89 Formula I was told that it preferred the 92 octane stuff but that it was equipped to deal with about anything I fed it. The only real concern is to make sure that you are getting enough detergents run through the motor. The ECM can deal with octane differences no problem. ----<last article. It's long >---------------------------------------- By Ken Mosher submitted by Eric Webb some data about the Sunoco CAM2 fuels from their literature: SUNOCO "Standard" Color......................Purple Research Octane.........115 Motor Octane..............107 R+M/2 ......................111 Specific Gravity........0.725 Reid Vapor Pressure..... 8# -- Distallation temp, degrees F -- Initial............90 10%............160 50%............220 Final...........360 SUNOCO "GT Unleaded" Color......................Natural Research Octane.........105 Motor Octane..............95 R+M/2 ......................100 Specific Gravity........0.760 Reid Vapor Pressure..... 8# -- Distallation temp, degrees F -- Initial............90 10%............150 50%............210 Final...........230 SUNOCO "Supreme" Color......................Blue Research Octane.........116 Motor Octane..............109 R+M/2 ......................112 Specific Gravity........0.715 Reid Vapor Pressure..... 8# -- Distallation temp, degrees F -- Initial............90 10%............155 50%............215 Final...........260 SUNOCO "Maximal" Color......................Red Research Octane.........118 Motor Octane..............115 R+M/2 ......................117 Specific Gravity........0.700 Reid Vapor Pressure..... 6# -- Distallation temp, degrees F -- Initial............100 10%............150 50%............220 Final...........240 And from Rich Lassitter's article in the GS Xtra ... how to mix your own brew: Formula #1 - Toulene ============================= R+M/2.........114 Cost...........$2.50/gal Mixtures with 92 Octane Premium -------------------------------- 10%...........94.2 Octane 20%...........96.4 Octane 30%...........98.6 Octane Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only raise octane 2-3 *points*, i.e. from 92 to 92.3. Often costs $3-5 for 12-16 ounces, when it can be purchased for less than $3/gal at chemical supply houses or paint stores. Formula #2 - Xylene ============================= R+M/2.........117 Cost...........$2.75/gal Mixtures with 92 Octane Premium -------------------------------- 10%...........94.5 Octane 20%...........97.0 Octane 30%...........99.5 Octane Notes: Similar to Toulene. 12-16 ounces will only raise octane 2-3 *points*, i.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race formula*. Formula #3 - Methyl-tertiary-butyl-ether (MTBE) ============================= R+M/2.........118 Cost...........$3.50/gal Mixtures with 92 Octane Premium -------------------------------- 10%...........94.6 Octane 20%...........97.2 Octane 30%...........99.8 Octane Notes: Oxygenate. Very common in octane booster products. Has lower BTU content than toulene or xylene, but oxygenate effect makes the gasoline burn better and produce more energy. Formula #4 - Methanol or Ethanol ============================= R+M/2.........101 Cost...........$0.60 - $1.75/gal Mixtures with 92 Octane Premium -------------------------------- 10%...........94.3 Octane (Methanol) 10%...........94.7 Octane (Ethanol) 20%...........Not Recommended Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank linings, rubber and aluminum if used in excessive ratios. Main ingredient in "Gas Dryers", combine with water. Formula #5 - Isopropyl Alcohol and Tertiary Butyl Alcohol ============================= R+M/2.........101 Cost...........$0.60-$1.50/gal Mixtures with 92 Octane Premium -------------------------------- 10%...........94.5 Octane 20%...........Not Recommended 30%...........Not Recommended Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing alcohol. How to make your own octane booster (this is the basic formula of one of the popular octane booster products). To make eight 16 ounce bottles (128 oz = 1 gal): 100 oz of toulene for octane boost 25 oz of mineral spirits (cleaning agent) 3 oz of transmission fluid (lubricating agent) This product is advertised as "octane booster with cleaning agent *and* lubricating agent!". Diesel fuel or kerosene can be substituted for mineral spirits and light turbine oil can be substituted for transmission fluid. Color can be added with petroleum dyes. I'll only add one comment regarding using methanol. In a word, don't. It attacks zinc and magnesium very rapidly. Guess what is in carburators and other fuel system parts.
Is That Additive Really A Negative?
Originally printed in RoadRider magazine, now known as Motorcycle Consumer News, August 1992
You can read the official rebuttal from QMI to this article, here.
Snake Oil!
Is That Additive Really A Negative?
Article by Fred Rau
Information for this article was compiled from reports andstudies by the University of Nevada Desert Research Center, DuPont
Chemical Company, Avco Lycoming (aircraft engine manufacturers),
North Dakota State University, Briggs and Stratton (engine
manufacturers), the University of Utah Engineering Experiment
Station, California State Polytechnic College and the National
Aeronautics and Space Administration's Lewis Research Center.
Road Rider does not claim to have all the answers. Nor do we
care to presume to tell you what to do. We have simply tried to
provide you with all the information we were able to dredge up on
this subject, in hopes it will help you in making your own, informed
decision.
You Can't Tell The Players Without A Program
On starting this project, we set out to find as many differentoil additives as we could buy. That turned out to be a mistake. There
were simply too many avail able! At the very first auto parts store
we visited, there were over two dozen different brand names
available. By the end of the day, we had identified over 40 different
oil additives for sale and realized we needed to rethink our strategy.
First of all, we found that if we checked the fine print on the
packages, quite a number of the additives came from the same
manufacturer. Also, we began to notice that the additives could be
separated into basic "groups" that seemed to carry approximately the
same ingredients and the same promises.
In the end, we divided our additives into four basic groups and
purchased at least three brands from three different manufacturers
for each group. We defined our four groups this way:
- Products that seemed to be nothing more than regular
50-rated engine oil (including standard additives) with PTFE (Teflon
TM) added.
- Products that seemed to be nothing more than regular
50-rated engine oil (including standard additives) with zinc
dialkyldithiophosphate added.
- Products containing (as near as we could determine) much
the same additives as are already found in most major brands of
engine oil, though in different quantities and combinations.
- Products made up primarily of solvents and/or detergents.
There may be some differences in chemical makeup within groups,
but that is impossible to tell since the additive manufacturers
refuse to list the specific ingredients of their products. We will
discuss each group individually.
The PTFE Mystery
Currently, the most common and popular oil additives on the market
are those that contain PTFE powders suspended in a regular,
over-the-counter type, 50-rated petroleum or synthetic engine oil.
PTFE is the common abbreviation used for Polytetrafloeraethylene,
more commonly known by the tradename "Teflon," which is a registered
trademark of the DuPont Chemical Corporation. Among those oil
additives we have identified as containing PTFE are: Slick 50, Liquid
Ring, Lubrilon, Microlon, Matrix, Petrolon (same company as Slick
50), QMl, and T-Plus (K-Mart). There are probably many more names in
use on many more products using PTFE. We have found that oil additive
makers like to market their products under a multitude of "private
brand" names.
While some of these products may contain other additives in
addition to PTFE, all seem to rely on the PTFE as their primary
active ingredient and all, without exception, do not list what other
ingredients they may contain.
Though they have gained rather wide acceptance among the
motoring public, oil additives containing PTFE have also garnered
their share of critics among experts in the field of lubrication. By
far the most damning testimonial against these products originally
came from the DuPont Chemical Corporation, inventor of PTFE and
holder of the patents and trademarks for Teflon. In a statement
issued about ten years ago, DuPont's Fluoropolymers Division
Product Specialist, J.F. Imbalzano said, "Teflon is not useful as an
ingredient in oil additives or oils used for internal combustion
engines."
At the time, DuPont threatened legal action against anyone who
used the name "Teflon" on any oil product destined for use in an
internal combustion engine, and refused to sell its PTFE powders to
any one who intended to use them for such purposes.
After a flurry of lawsuits from oil additive makers, claiming
DuPont could not prove that PTFE was harmful to engines, DuPont was
forced to once again begin selling their PTFE to the additive
producers. The additive makers like to claim this is some kind of
"proof' that their products work, when in fact it is nothing more
than proof that the American legal ethic of "innocent until proven
guilty" is still alive and well. The decision against Dupont involved
what is called "restraint of trade." You can't refuse to sell a
product to someone just because there is a possibility they might use
it for a purpose other than what you intended it for.
It should be noted that DuPont's official position on the use of
PTFE in engine oils remains carefully aloof and non-commital, for
obvious legal reasons. DuPont states that though they sell PTFE to
oil additive producers, they have "no proof of the validity of the
additive makers' claims." They further state that they have "no
knowledge of any advantage gained through the use of PTFE in engine
oil."
Fear of potential lawsuits for possible misrepresentation of a
product seem to run much higher among those with the most to lose.
After DuPont's decision and attempt to halt the use of PTFE in
engine oils, several of the oil additive companies simply went
elsewhere for their PTFE powders, such as purchasing them in other
countries. In some cases, they disguise or hype their PTFE as being
something different or special by listing it under one of their own
tradenames. That doesn't change the fact that it is still PTFE.
In addition, there is some evidence that certain supplies of
PTFE powders (from manufacturers other than DuPont) are of a cruder
version than the original, made with larger sized flakes that are
more likely to "settle out" in your oil or clog up your filters. One
fairly good indication that a product contains this kind of PTFE is
if the instructions for its use advise you to "shake well before
using." It only stands to reason that if the manufacturer knows the
solids in his product will settle to the bottom of a container while
sitting on a shelf, the same thing is going to hap pen inside your
engine when it is left idle for any period of time.
The problem with putting PTFE in your oil, as explained to us by
several industry experts, is that PTFE is a solid. The additive
makers claim this solid "coats" the moving parts in an engine (though
that is far from being scientifically proven). Slick 50 is currently
both the most aggressive advertiser and the most popular seller, with
claims of over 14 million treatments sold. However, such solids seem
even more inclined to coat non-moving parts, like oil passages and
filters. After all, if it can build up under the pressures and
friction exerted on a cylinder wall, then it stands to reason it
should build up even better in places with low pressures and
virtually no friction.
This conclusion seems to be borne out by tests on oil additives
containing PTFE conducted by the NASA Lewis Research Center, which
said in their report, "In the types of bearing surface contact we
have looked at, we have seen no benefit. In some cases we have seen
detrimental effect. The solids in the oil tend to accumulate at
inlets and act as a dam, which simply blocks the oil from entering.
Instead of helping, it is actually depriving parts of lubricant."
Remember, PTFE in oil additives is a suspended solid. Now think
about why you have an oil filter on your engine. To remove suspended
solids, right? Right. Therefore it would seem to follow that if your
oil filter is doing its job, it will collect as much of the PTFE as
possible, as quickly as possible. This can result in a clogged oil
filter and decreased oil pres sure throughout your engine.
In response to our inquiries about this sort of problem, several
of the PTFE pushers responded that their particulates were of a
sub-micron size, capable of passing through an ordinary oil filter
unrestricted. This certainly sounds good, and may in some cases
actually be true, but it makes little difference when you know the
rest of the story. You see, PTFE has other qualities besides being a
friction reducer: It expands radically when exposed to heat. So even
if those particles are small enough to pass through your filter when
you purchase them, they very well may not be when your engine reaches
normal operating temperature.
Here again, the' scientific evidence seems to support this, as
in tests conducted by researchers at the University of Utah
Engineering Experiment Station involving Petrolon additive with PTFE.
The Petrolon test report states, "There was a pressure drop
across the oil filter resulting from possible clogging of small
passageways." In addition, oil analysis showed that iron
contamination doubled after using the treatment, indicating that
engine wear didn't go down - it appeared to shoot up.
This particular report was paid for by Petrolon (marketers of
Slick 50), and was not all bad news for their products. The tests,
conducted on a Chevrolet six-cylinder automobile engine, showed that
after treatment with the PTFE additive the test engine's friction was
reduced by 13.1 per- cent. Also, output horsepower increased from 5.3
percent to 8.1 percent, and fuel economy improved from 11.8 percent
under light load to 3.8 percent under heavy load.
These are the kind of results an aggressive marketing company
like Petrolon can really sink their teeth into. If we only reported
the results in the last paragraph to you, you'd be inclined to think
Slick 50 was indeed a magic engine elixir. What you have to keep in
mind is that often times the benefits (like increased horse power and
fuel economy) may be out weighed by some serious drawbacks (like the
indications of reduced oil pressure and increased wear rate).
The Plot Thickens
Just as we were about to go to press with this article, we werecontacted by the public relations firm of Trent and Company, an
outfit with a prestigious address in the Empire State Building, New
York. They advised us they were working for a company called QMI out
of Lakeland, Florida, that was marketing a "technological
breakthrough" product in oil additives. Naturally, we asked them to
send us all pertinent information, including any testing and
research data.
What we got was pretty much what we expected. QMI's oil
additive, according to their press release, uses "ten times more PTFE
resins than its closest competitor." Using the "unique SX-6000
formula," they say they are the only company to use "aqueous
dispersion resin which means the microns (particle sizes) are
extensively smaller and can penetrate tight areas." This, they claim,
"completely eliminates the problem of clogged filters and oil
passages."
Intrigued by their press release, we set up a telephone
interview with their Vice- President of Technical Services, Mr. Owen
Heatwole. Mr. Heatwole's name was immediately recognized by us as one
that had popped in earlier research of this subject as a former
employee of Petrolon, a company whose name seems inextricably linked
in some fashion or another with virtually every PTFE-related additive
maker in the country.
Mr. Heatwole was a charming and persuasive talker with a knack
for avoiding direct answers as good as any seasoned politician. His
glib pitch for his product was the best we've ever heard, but when
dissected and pared down to the verifiable facts, it actually said
very little.
When we asked about the ingredients in QMI's treatments, we got
almost exactly the response we expected. Mr. Heatwole said he would
"have to avoid discussing specifics about the formula, for
proprietary reasons."
After telling us that QMI was being used by "a major oil
company," a "nuclear plant owned by a major corporation" and a
"major engine manufacturer," Mr. Heatwole followed up with,
"Naturally, I can't reveal their names- for proprietary reasons."
He further claimed to have extensive testing and research data
available from a "major laboratory," proving conclusively how
effective QMI was. When we asked for the name of the lab, can you
guess? Yup, "We can't give out that information, for proprietary
reasons."
What QMI did give us was the typical "testimonials," though we
must admit theirs came from more recognizable sources than usual.
They seem to have won over the likes of both Team Kawasaki and Bobby
Unser, who evidently endorse and use QMI in their racing engines. Mr.
Heatwole was very proud of the fact that their product was being
used in engines that he himself admitted are "torn down and
completely inspected on a weekly basis." Of course, what he left out
is that those same engines are almost totally rebuilt every time
they're torn down. So what does that prove in terms of his product
reducing wear and promoting engine longevity? Virtually nothing.
Mr. Heatwole declined to name the source of QMI's PTFE supply
"for proprietary reasons." He bragged that their product is sold
under many different private labels, but refused to identify those
labels "for proprietary reasons." When asked about the actual size of
the PTFE particles used in QMI, he claimed they were measured as
"sub-micron in size" by a "major motor laboratory" which he couldn't
identify - you guessed it - for "proprietary reasons."
After about an hour of listening to "don't quote me on this,"
"I'll have to deny that if you print it," and "I can't reveal that,"
we asked Mr. Heatwole if there was something we could print.
"Certainly," he said, "Here's a good quote for you: 'The radical
growth in technology has overcome the problem areas associated with
PTFE in the I980s'"
"Not bad," we said. Then we asked to whom we might attribute
this gem of wisdom. DuPont Chemical, perhaps?
"Me," said Mr. Heatwole. "I said that."
QMI's press releases like to quote the Guinness Book Of Records
in saying that PTFE is "The slickest substance known to man." Far be
it from us to take exception to the Guinness Book, but we doubt that
PTFE is much slicker than some of the people marketing it.
The Zinc Question
The latest "miracle ingredient" in oil additives, attempting tousurp PTFE's cure-all throne, is zinc dialkyldithiophosphate, which
we will refer to here after as simply "zinc."
Purveyors of the new zinc-related products claim they can prove
absolute superiority over the PTFE-related products. Naturally, the
PTFE crowd claim exactly the same, in reverse.
Zinc is contained as part of the standard additive package in
virtually every major brand of engine oil sold today, varying from a
low volume of 0.10 per cent in brands such as Valvoline All Climate
and Chevron l5W-50, to a high volume of 0.20 percent in brands such
as Valvoline Race and Pennzoil GT Performance.
Organic zinc compounds are used as extreme pressure, anti-wear
additives, and are therefore found in larger amounts in oils
specifically blended for high-revving, turbocharged or racing
applications. The zinc in your oil comes into play only when there is
actual metal-to-metal con tact within your engine, which should never
occur under normal operating conditions. However, if you race your
bike, or occasionally play tag with the redline on the tach, the zinc
is your last line of defense. Under extreme conditions, the zinc
compounds react with the metal to prevent scuffing, particularly
between cylinder bores and piston rings.
However - and this is the important part to remember - available
research shows that more zinc does not give you more protection, it
merely prolongs the protection if the rate of metal-to-metal contact
is abnormally high or extended. So unless you plan on spending a
couple of hours dragging your knee at Laguna Seca, adding extra zinc
compounds to your oil is usually a waste. Also, keep in mind that
high zinc content can lead to deposit formation on your valves, and
spark plug fouling.
Among the products we found containing zinc
dialkyldithiophosphate were Mechanics Brand Engine Tune Up, K Mart
Super Oil Treatment, and STP Engine Treatment With XEP2. The only
reason we can easily identify the additives with the new zinc
compounds is that they are required to carry a Federally mandated
warning label indicating they contain a hazardous substance. The zinc
phosphate they contain is a known eye irritant, capable of inflicting
severe harm if it comes in contact with your eyes. If you insist on
using one of these products, please wear protective goggles and
exercise extreme caution.
As we mentioned, organic zinc compounds are already found in
virtually every major brand of oil, both automotive and motorcycle.
However, in recent years the oil companies voluntarily reduced the
amount of zinc content in most of their products after research
indicated the zinc was responsible for premature deterioration and
damage to catalytic converters. Obviously this situation would not
affect 99 percent of all the motorcycles on the road - however, it
could have been a factor with the newer BMW converter - equipped
bikes.
Since the reduction in zinc content was implemented solely for
the protection of catalytic converters, it is possible that some
motorcycles might benefit from a slight increase in zinc content in
their oils. This has been taken into account by at least one oil
company, Spectro, which offers 0.02 to 0.03 percent more zinc
compounds in its motorcycle oils than in its automotive oils.
Since Spectro (Golden 4 brand, in this case) is a synthetic
blend lubricant designed for extended drain intervals, this increase
seems to be wholly justified. Also, available research indicates that
Spectro has, in this case, achieved a sensible balance for extended
application without increasing the zinc content to the point that it
is likely to cause spark plug fouling or present a threat to
converter- equipped BMW models.
It would appear that someone at Spectro did their homework.
Increased Standard Additives
(More Is Not Necessarily Better)Though some additives may not contain anything harmful to your
engine, and even some things that could be beneficial, most experts
still recommend that you avoid their use. The reason for this is that
your oil, as purchased from one of the major oil companies, already
contains a very extensive additive package.
This package is made up of numerous, specific additive
components, blended to achieve a specific formula that will meet the
requirements of your engine. Usually, at least several of these
additives will be synergistic. That is, they react mutually, in
groups of two or more, to create an effect that none of them could
attain individually. Changing or adding to this formula can upset the
balance and negate the protective effect the formula was meant to
achieve, even if you are only adding more of something that was
already included in the initial package.
If it helps, try to think of your oil like a cake recipe. Just
because the original recipe calls for two eggs (which makes for a
very moist and tasty cake), do you think adding four more eggs is
going to make the cake better? Of course not. You're going to upset
the carefully calculated balance of ingredients and magnify the
effect the eggs have on the recipe to the point that it ruins the
entire cake. Adding more of a specific additive already contained in
your oil is likely to produce similar results.
This information should also be taken into account when adding
to the oil already in your bike or when mixing oils for any reason,
such as synthetic with petroleum. In these cases, always make sure
the oils you are putting together have the same rating (SA, SE, SC,
etc.). This tells you their additive packages are basically the same,
or at least compatible, and are less likely to upset the balance or
counteract each other.
Detergents And Solvents
Many of the older, better-known oil treatments on the market donot make claims nearly so lavish as the new upstarts. Old standbys
like Bardahl, Rislone and Marvel Mystery Oil, instead offer things
like "quieter lifters," "reduced oil burning" and a "cleaner
engine."
Most of these products are made up of solvents and detergents
designed to dissolve sludge and carbon deposits inside your engine so
they can be flushed or burned out. Wynn's Friction Proofing Oil, for
example, is 83 percent kerosene. Other brands use naphthalene,
xylene, acetone and isopropanol. Usually, these ingredients will be
found in a base of standard mineral oil.
In general, these products are designed to do just the opposite
of what the PTFE and zinc phosphate additives claim to do. Instead of
leaving behind a "coating" or a "plating" on your engine surfaces,
they are designed to strip away such things.
All of these products will strip sludge and deposits out and
clean up your engine, particularly if it is an older, abused one. The
problem is, unless you have some way of determining just how much is
needed to remove your deposits without going any further, such
solvents also can strip away the boundary lubrication layer provided
by your oil. Overuse of solvents is an easy trap to fall into, and
one which can promote harmful metal-to-metal contact within your
engine.
As a general rule of thumb these products had their place and
were at least moderately useful on older automobile and motorcycle
engines of the Fifties and Sixties, but are basically unneeded on the
more efficient engine designs of the past two decades.
The Infamous "No Oil" Demo
At at least three major motorcycle rallies this past year, wehave witnessed live demonstrations put on to demonstrate the
effectiveness of certain oil additives. The demonstrators would
have a bench- mounted engine which they would fill with oil and a
prescribed dose of their "miracle additive." After running the engine
for a while they would stop it, drain out the oil and start it up
again. Instant magic! The engine would run perfectly well for hours
on end, seemingly proving the effectiveness of the additive which had
supposedly "coated" the inside of the engine so well it didn't even
need the oil to run. In one case, we saw this done with an actual
motorcycle, which would be rid den around the parking lot after
having its oil drained. A pretty convincing demonstration - until you
know the facts.
Since some of these demonstrations were conducted using Briggs
and Stratton engines, the Briggs and Stratton Company itself
decided to run a similar, but somewhat more scientific, experiment.
Taking two brand-new, identical engines straight off their assembly
line, they set them up for bench-testing. The only difference was
that one had the special additive included with its oil and the other
did not. Both were operated for 20 hours before being shut down and
having the oil drained from them. Then both were started up again and
allowed to run for another 20 straight hours. Neither engine seemed
to have any problem performing this "minor miracle."
After the second 20-hour run, both engines were completely torn
down and inspected by the company's engineers. What they found was
that both engines suffered from scored crankpin bearings, but the
engine treated with the additive also suffered from heavy cylinder
bore damage that was not evident on the untreated engine.
This points out once again the inherent problem with particulate
oil additives: They can cause oil starvation. This is particularly
true in the area of piston rings, where there is a critical need for
adequate oil flow. In practically all of the reports and studies on
oil additives, and particularly those involving suspended solids like
PTFE, this has been reported as a major area of engine damage.
The Racing Perspective
Among the most convincing testimonials in favor of oil additivesare those that come from professional racers or racing teams. As
noted previously, some of the oil additive products actually are
capable of producing less engine friction, better gas mileage and
higher horsepower out put. In the world of professional racing, the
split-second advantage that might be gained from using such a product
could be the difference between victory and defeat.
Virtually all of the downside or detrimental effects attached to
these products are related to extended, long-term usage. For
short-life, high-revving, ultra-high performance engines designed to
last no longer than one racing season (or in some cases, one single
race), the long-term effects of oil additives need not even be
considered.
Racers also use special high-adhesion tires that give much
better traction and control than our normal street tires, but you
certainly wouldn't want to go touring on them, since they're designed
to wear out in several hundred (or less) miles. Just because certain
oil additives may be beneficial in a competitive context is no reason
to believe they would be equally beneficial in a touring context.
The Best of The Worst
Not all engine oil additives are as potentially harmful as someof those we have described here. However, the best that can be said
of those that have not proved to be harmful is that they haven't been
proved to offer any real benefits, either. In some cases, introducing
an additive with a compatible package of components to your oil in
the right proportion and at the right time can conceivably extend the
life of your oil. However, in every case we have studied it proves
out that it would actually have been cheaper to simply change the
engine oil instead.
In addition, recent new evidence has come to light that makes
using almost any additive a game of Russian Roulette. Since the
additive distributors do not list the ingredients contained within
their products, you never know for sure just what you are putting in
your engine.
Recent tests have shown that even some of the most inoffensive
additives contain products which, though harmless in their initial
state, convert to hydrofluoric acid when exposed to the temperatures
inside a firing cylinder. This acid is formed as part of the exhaust
gases, and though it is instantly expelled from your engine and seems
to do it no harm, the gases collect inside your exhaust system and
eat away at your mufflers from the inside out.
Whatever The Market Will Bear
The pricing of oil additives seems to follow no particularpattern whatsoever. Even among those products that seem to be almost
identical, chemically, retail prices covered an extremely wide range.
For example:
One 32-ounce bottle of Slick 50 (with PTFE) cost us $29.95 at a
discount house that listed the retail price as $59.95, while a
32-ounce bottle of T-Plus (which claims to carry twice as much PTFE
as the Slick 50) cost us only $15.88.
A 32-ounce bottle of STP Engine Treatment (containing what they
call XEP2), which they claim they can prove "outperforms leading PTFE
engine treatments," cost us $17.97. Yet a can of K Mart Super Oil
Treatment, which listed the same zinc-derivative ingredient as that
listed for the XEP2, cost us a paltry $2.67.
Industry experts estimate that the actual cost of producing most
oil additives is from one-tenth to one-twentieth of the asking
retail price. Certainly no additive manufacturer has come forward
with any exotic, high-cost ingredient or list of ingredients to
dispute this claim. As an interesting note along with this, back
before there was so much competition in the field to drive prices
down, Petrolon (Slick 50) was selling their PTFE products for as much
as $400 per treatment! The words "buyer beware" seem to take on very
real significance when talking about oil additives.
The Psychological Placebo
You have to wonder, with the volume of evidence accumulating againstoil additives, why so many of us still buy them. That's the
million-dollar question, and it's just as difficult to answer as why
so many of us smoke cigarettes, drink hard liquor or engage in any
other number of questionable activities. We know they aren't good for
us - but we go ahead and do them anyway.
Part of the answer may lie in what some psychiatrists call the
"psychological placebo effect." Simply put, that means that many of
us hunger for that peace of mind that comes with believing we have
purchased the absolute best or most protection we can possibly get.
Even better, there's that wonderfully smug feeling that comes
with thinking we might be a step ahead of the pack, possessing
knowledge of something just a bit better than everyone else.
Then again, perhaps it comes from an ancient, deep-seated need
we all seem to have to believe in magic. There has never been any
shortage of unscrupulous types ready to cash in on our willingness to
believe that there's some magical mystery potion we can buy to help
us lose weight, grow hair, attract the opposite sex or make our
engines run longer and better. I doubt that there's a one of us who
hasn't fallen for one of these at least once in our lifetimes. We
just want it to be true so bad that we can't help ourselves.
Testimonial Hype vs. Scientific Analysis
In general, most producers of oil additives rely on personal"testimonials" to advertise and promote their products. A typical
print advertisement will be one or more letters from a satisfied
customer stating something like, "1 have used Brand X in my engine
for 2 years and 50,000 miles and it runs smoother and gets better
gas mileage than ever before. I love this product and would recommend
it to anyone."
Such evidence is referred to as "anecdotal" and is most commonly
used to pro mote such things as miracle weight loss diets and
astrology.
Whenever I see one of these ads I am reminded of a stunt played
out several years ago by Allen Funt of "Candid Camera" that clearly
demonstrated the side of human nature that makes such advertising
possible.
With cameras in full view, fake "product demonstrators" would
offer people passing through a grocery store the opportunity to
taste-test a "new soft drink." What the victims didn't know was that
they were being given a horrendous concoction of castor oil, garlic
juice, tabasco sauce and several other foul-tasting ingredients.
After taking a nice, big swallow, as instructed by the demonstrators,
the unwitting victims provided huge laughs for the audience by
desperately trying to conceal their anguish and disgust. Some
literally turned away from the cameras and spit the offending potion
on the floor.
The fascinating part came when about one out of four of the
victims would actu ally turn back to the cameras and proclaim the new
drink was "Great" or "Unique" or, in several cases, "One of the best
things I've ever tasted!" Go figure.
The point is, compiling "personal testimonials" for a product is
one of the easiest things an advertising company can do - and one of
the safest, too. You see, as long as they are only expressing some
one else's personal opinion, they don't have to prove a thing! It's
just an opinion, and needs no basis in fact whatsoever.
On the other hand, there has been documented, careful
scientific analysis done on numerous oil additives by accredited
institutions and researchers.
For example:
Avco Lycoming, a major manufacturer of aircraft engines,
states, "We have tried every additive we could find on the market,
and they are all worthless."
Briggs and Stratton, renowned builders of some of the most
durable engines in the world, says in their report on engine oil
additives, "They do not appear to offer any benefits."
North Dakota State University conducted tests on oil
additives and said in their report, "The theory sounds good- the only
problem is that the products simply don't work."
And finally, Ed Hackett, chemist at the University of Nevada
Desert Research Center, says, "Oil additives should not be used. The
oil companies have gone to great lengths to develop an additive pack
age that meets the vehicle's requirements. If you add anything to
this oil you may upset the balance and prevent the oil from
performing to specification."
Petrolon, Inc., of Houston, Texas, makers of Petrolon and
producers of at least a dozen other lubrication products containing
PTFE, including Slick 50 and Slick 30 Motorcycle Formula, claim that,
"Multiple tests by independent laboratories have shown that when
properly applied to an automotive engine, Slick 50 Engine Formula
reduces wear on engine parts. Test results have shown that Slick 50
treated engines sustained 50 percent less wear than test engines run
with premium motor oil alone."
Sounds pretty convincing, doesn't it?
The problem is, Petrolon and the other oil additive companies
that claim "scientific evidence" from "independent laboratories,"
all refuse to identify the laboratories that conducted the tests or
the criteria under which the tests were conducted. They claim they
are "contractually bound" by the laboratories to not reveal their
identities.
In addition, the claim of "50 percent less wear" has never
been proven on anything approaching a long-term basis. Typical
examples used to support the additive makers' claims involve engines
run from 100 to 200 hours after treatment, during which time the
amount of wear particles in the oil decreased. While this has proven
to be true in some cases, it has also been proven that after 400 to
500 hours of running the test engines invariably reverted to
producing just as many wear particles as before treatment, and in
some cases, even more.
No matter what the additive makers would like you to believe,
nothing has been proven to stop normal engine wear.
You will note that all of the research facilities quoted in this
article are clearly identified. They have no problem with making
their findings public. You will also note that virtually all of their
findings about oil additives are negative. That's not because we
wanted to give a biased report against oil additives - it's because
we couldn't find a single laboratory, engine manufacturer or
independent research facility who would make a public claim, with
their name attached to it, that any of the additives were actually
beneficial to an engine. The conclusion seems inescapable.
As a final note on advertising hype versus the real world, we
saw a television ad the other night for Slick 50 oil additive. The ad
encouraged people to buy their product on the basis of the fact that,
"Over 14 million Americans have tried Slick 50!" Great. We're sure
you could just as easily say, "Over 14 million Americans have smoked
cigarettes!"-but is that really any reason for you to try it? Of
course not, because you've seen the scientific evidence of the harm
it can do. The exact same principle applies here.
In Conclusion
The major oil companies are some of the richest, most powerfuland aggressive corporations in world. They own multi- million dollar
research facilities manned by some of the best chemical engineers
money can hire. It is probably safe to say that any one of them has
the capabilities and resources at hand in marketing, distribution,
advertising, research and product development equal to 20 times that
of any of the independent additive companies. It therefore stands to
reason that if any of these additive products were actu ally capable
of improving the capabilities of engine lubricants, the major oil
companies would have been able to determine that and to find some way
to cash in on it.
Yet of all the oil additives we found, none carried the name or
endorsement of any of the major oil producers.
In addition, all of the major vehicle and engine manufacturers
spend millions of dollars each year trying to increase the longevity
of their products, and millions more paying off warranty claims when
their products fail. Again, it only stands to reason that if they
thought any of these additives would increase the life or improve the
performance of their engines, they would be actively using and
selling them - or at least endorsing their use.
Instead, many of them advise against the use of these additives
and, in some cases, threaten to void their warranty coverage if such
things are found to be used in their products.
In any story of this nature, absolute "facts" are virtually
impossible to come by. Opinions abound. Evidence that points one
direction or the other is avail able, but has to be carefully
ferreted out, and is not always totally reliable or completely
verifiable.
In this environment, conclusions reached by known,
knowledgeable experts in the field must be given a certain amount of
weight. Conclusions reached by unknown, unidentifiable sources must
be discounted almost totally. That which is left must be weighed, one
side against the other, in an attempt to reach a "reasonable"
conclusion.
In the case of oil additives, there is a considerable volume of
evidence against their effectiveness. This evidence comes from
well-known and identifiable expert sources, including independent
research laboratories, state universities, major engine
manufacturers, and even NASA.
Against this rather formidable barrage of scientific research,
additive makers offer not much more than their own claims of
effectiveness, plus questionable and totally unscientific personal
testimonials. Though the purveyors of these products state they have
studies from other independent laboratories supporting their claims,
they refuse to identify the labs or provide copies of the research.
The only test results they will share are those from their own
testing departments, which must, by their very nature, be taken with
a rather large grain of salt.
A list of references on Engine Management Currently maintained by Steve Ravet sravet@bangate.compaq.com ----------------------------------------------------------------------- Books ----------------------------------------------------------------------- Adler, Ulrich, _Electronic Gasoline Fuel-Injection System with Lambda Closed-Loop Control, L-Jetronic: Technical Instruction_, Robert Bosch GmbH, copyright 1985, ISBN 1-85-226008-4. (yellow book, 20 numbered pages; this is written on the back cover: "English translation of the German edition dated: September 1985.") Adler, Ulrich, _Mechanical Gasoline Fuel-Injection System with Lambda Closed-Loop Control, K-Jetronic: Technical Instruction_, Robert Bosch GmbH, copyright 1981, ISBN 1-85-226030-0. (yellow book, 24 numbered pages; this is written on the back cover: "English translation of the 2nd German edition dated: September 1985.") Adler, Ulrich, _Combined Ignition and Fuel-Injection System with Lambda Closed-Loop Control, Motronic: Technical Instruction_, Robert Bosch GmbH, copyright 1985, ISBN 1-85-226009-2. (yellow book, 44 numbered pages; this is written on the back cover: "English translation of the 2nd German edition from September 1985.") Adler et al, "Automotive Electric/Electronic Systems", Robert Bosch GmbH, Stuttgart, Germany, ISBN 0-89883-509-7, 1988. This is the "red" handbook. Covers all forms of automotive systems. Good general reading with excellent coverage of basic functions like <a href="http://www.andysautosport.com/starters.html">starters</a>, <a href="http://www.andysautosport.com/alternators.html">alternators</a>, <a href="http://www.andysautosport.com/ignition_coils.html">ignition</a>, <a href="http://www.andysautosport.com/spark_plugs.html">sparkplugs</a>. Covers some detail of Bosch's <a href="http://www.andysautosport.com/fuel_injectors.html">fuel injection</a> systems. Available from the SAE on sale for $19 (order B-528). Adler et al, "Automotive Handbook, 3rd Edition", Robert Bentley, Cambridge, MA, ISBN 0-8376-0330-7, 1993. + This is the "blue" handbook which used to be pocket size. Covers all forms of automotive design and systems. Good reference source, but expressed in metric. Has conversion tables. Covers materials well. Some data on emissions (478-489) similar to 2nd Edition. Also has data on some of the representative automobiles from various world companies in back section. Available from the SAE for $29 (order BOSCH3). Price for SAE members is $23. _Bosch Electronic Fuel Injection Systems, Shop Manual_, , Motorbooks International, Osceola, Wisconsin, 1986, ISBN 0-87938-237-6. (maintenance manual for Audi, BMW, Cadillac, Datsun, Mercedes, Opel, Porsche, Renault, Saab, Volkswagen, and Volvo, model years 1970 - 1979). DaRosa -- Fundamentals of Energy Processes Very general, with an excellent chapter or two on combustion, and lots of other source of energy discussion. $60 Jeff Hartman,"Fuel injection - Installation, Performance tuning, Modifications" ISBN 0-87938-743-2 Publisher Motorbooks international, PO Box 1, Osceola, WI 54020 1-800-826-6600 (in the US), Reccomended Price $19.95 US. Probably the best value for money book on EFI. The book has snippets of everything - If it had detail on all the subjects it mentioned it would be the definitive reference. The Audience is intended as street rodders mainly, but there are good bits and peices for the DIY_EFI'er - Reccomended reading. Heywood, J.B., "Internal Combustion Engine Fundamentals", McGraw-Hill, USA, ISBN 0-07-028637-x, 1988. College text on IC engine design and theory. General reference on engine topics. Also contains many references to other works. Available from the SAE for $69 (order B-526). Lenz, D.H.P., "Mixture Formation in Spark-Ignition Engines", SAE, Warrendale, PA, ISBN 1-56091-188-3, 1992. Excellent text on carbureation, combustion and fuel infection concepts. Some important data on emissions (70-74, 249-251) with description of trends over years. This book also published by Springer-Verlag/Wien, NY, who translated it from German (Lenz, Gemischbildung bei Ottomotoren) in 1990. Available from SAE on sale for $55 (order R-113). Price for SAE members is $45. I actually bought a copy for $39 at the SAE Congress last month. Mitchell International, Inc., _Mitchell's Electronic Fuel Injection Troubleshooting Guide: Import Vehicles_, Fisher Books, Tucson, Arizona, 1989, ISBN 1-55561-031-5. (chapter contents include Bosch D, K, KE, L, LH, and Digifant (Japanese and European); Daihatsu; Honda PGM-FI; Isuzu I-TEC; Lucas-Bosch; Mazda RE-EGI; Mitsubishi ECI and MPFI; Nissan TBI; Subaru SPFI; this book has the EFI system wiring diagrams of many import cars.) Mitchell International, Inc., _Mitchell's Electronic Fuel Injection Troubleshooting Guide: Domestic Vehicles, Fisher Books, Tucson, Arizona, 1991, ISBN 1-55561-032-3. (chapter contents include AMC/Jeep; AMC; AMC/RENIX; AMC/RENIX II; Bosch; Chrysler; Eagle; Ford; GM; this book has the EFI system wiring diagrams of many domestic cars.) Norbye, Jan P., _Automotive Fuel Injection Systems, A Technical Guide_, Motorbooks International, Osceola, Wisconsin, 1981, ISBN 0-87938-139-6. (primarily a history and description of fuel injection systems, includes chapters on Bosch Mechanical Systems for Mercedes-Benz Cars, Kugelfischer Fuel Injection, Rochester Fuel Injection, The Bendix Electrojector, Cadillac and the Bendix Analog and Digital Fuel-Injection Systems, Bosch L- and K- Jetronic, Motronic, Mono-Jetronic, Lucas Digital Fuel Injection, Chrysler's Single-Point Injection; Ford's Electronic Engine Control System, Zenith Fuel-Management Systems, Fiat/Marelli Experimental System, Bosch / Pierburg Electronic <a href="http://www.andysautosport.com/carburetors.html">Carburetor</a>, Aftermarket Fuel Injection) Probst, C.O., "Bosch Fuel Injection & Engine Management", Robert Bentley, Cambridge, MA, ISBN 0-8376-0300-5, 1989. Covers most of the Bosch systems from D-Jetronic through Motronic. Covers variety of vehicles. Has good section in begining on combustion and emissions information, but a better description is in other BOSCH texts and sources. Available from the SAE on sale for $19 (order B-557). Probst, C.O., "How to Understand, Service and Modify Ford Fuel Injection and Electronic Engine Control", Robert Bentley, Cambridge, MA, ISBN 0-8376-0301-3, 1993. Covers basic engine control theory and Ford systems to 1988. Excellent book on topic. Similar to author's other work on Bosch systems. Available from SAE for $30 (order B-584). Ribbens, William B., Mansour, Norman P., et al, _Understanding Automotive Electronics_, third edition, Howard W. Sams & Company, Indianapolis, Indiana, 1988, ISBN 0-672-27064-6. (Contents includes Automotive Fundamentals, The Systems Approach to Control and Instrumentation, Electronics Fundamentals, Microcomputer Instrumentation and Control, Sensors and <a href="http://www.andysautosport.com/linear_actuators.html">Actuators</a>, The Basics of Electronic Engine Control, Digital Engine Control System, Vehicle Motion Control, Automotive Instrumentation, Diagnostics, Future Automotive Electronics Systems) Watson, B., "How to Tune and Modify Bosch Fuel Injection", Motorbooks International, Osceola, WI, ISBN 0-87938-570-7, 1992. Covers most of the Bosch systems from D-Jetronic through LH-Jetronic. Mainly aimed at VW. Has good section in begining on testing electronic components. Minimal amount of emissions information - better description is in other BOSCH texts and sources. Cost $19.95 in 1994. Watson, Ben, _How to Tune and Modify Ford Fuel Injection_, Motorbooks International, Osceola, Wisconsin, 1992, ISBN 0-87938-621-5. ("For Fuel-Injected Ford Cars and Trucks with EEC III and EEC IV Engine Maintenance Systems," chapters include History of Fuel Injection, Brief Overview of Electronics, Tools, Tuning the Fuel-injected Engine, Automotive Emissions, EEC III, EEC IV Components and Operation, EEC IV Onboard Diagnostics, Troubleshooting by Symptom, <a href="http://www.andysautosport.com/performance.html">Performance</a> Modifications, Legalities of Engine Modification; the performance chapter is weak, only 10 pages). Watson, Ben, _How to Repair and Modify Chevrolet Fuel Injection, Motorbooks International, Osceola, Wisconsin, 1991, ISBN 0-87938-502-2. Electronic controls and sensors: proceedings of the SAE International Congress and Exposition (1992: Detroit, MI). ISBN 1-56091-215-4. This book is 120 pages long. Unfortunately, I do not have it (yet) as it is in an ATT library in NJ whereas I'm in IL! If you choose to purchase it, the ISBN and title should be sufficient for a bookstore to track it down. I recall this book has some articles on nifty research done in universities in Europe on adaptive controls and some stuff on a truly exotic oxygen sensor which allows more than bang-bang control of the a/f mixture. Laser/Talon Tech Info Manual Call 1-800-626-1523 and ask for the 1990 Laser/Talon Tech Info Manual part number 81-699-9039. Shipping will probably be more than the cost of this ~200 page book. They take plastic. ----------------------------------------------------------------------- Papers ----------------------------------------------------------------------- SAE (412)776-4970 SAE (412)776-0790 FAX 750346 -- HEI-A New Ignition System Through New Technology It covers the charge time question as well at their solution. If you've not yet read the paper, it describes some really clever innovations: adjustable dwell depending on how near saturation, a 5.5 amp limit in the driver so you could have a low resistance for fast saturation times at high speeds, but that wouldn't fry at low speeds. 790742 -- Readable paper on the Ford CFI 5.0L 1980 cars. It covers most of the 'twiddle factors' required to get the vehicle running properly. 800164 -- Covers GM TBI system. Easy reading. 810449 -- Mathematical Model of a Throttle Body Fuel Injection System Discusses effect of <a href="http://www.andysautosport.com/batteries.html">battery</a> voltage on injectors and <a href="http://www.andysautosport.com/fuel_pumps.html">fuel pump</a> pressure 810494 -- 810495 -- 800468 -- _Hot Wire Air Mass Meter - A New Air Flow Meter for Gasoline Fuel Injection Systems_,Sauer, Rudolf, 1980, ISSN 0148-7191. (The author is from Bosch. This paper appears to be one of the first on MAF meters - the classical Bosch design with the thin platinum wire in the direct air flow. It has many equations explaining its operation.) 830615 -- _Hot Wire Air Flow Meter for Engine Control System_, Nishimura, Yutaka; Ohyama, Yoshishige; Sasayama, Takao; et al., 1983, ISSN 0148-7191. (The authors are from Hitachi Ltd. This paper describes the Hitachi type MAF, which measures air flow in a bypass air passage. I believe that this type of MAF is being used on Ford cars, starting with the Mustang GT in 1987.) 840137 -- _Bosch Mass Air Flow Meter: Status and Further Aspects_, Sumai, Jaihind, and Sauer, Rudolf, 1984. (The authors are from Bosch. This paper discusses flow passages, air flow around the thermal element, use of wire grid in the air flow stream, mechanical forces on the sensor element, dirt build up on the thermal sensor element, response rate, velocity profiles, and influence of altitude on <a href="http://www.andysautosport.com/intake_manifolds.html">intake manifold</a> pulsations. Actual test data is provided.) 880561 -- Frequency Domain Characterization of Mass Flow Sensors, by W. C. Follmer, 1988. 890298 -- _Switching Controlled Thermal Mass Air Flow Sensor_, Tanimoto, Kohji; Bessho, Mikio; Inada, Masanori; 1989, ISSN 0148-7191. (Reprinted from SP-771 - _Sensors and Actuators: 1989_. Authors are from Mitsubishi Electric. This paper discusses a typical MAF meter using a switching transistor to supply the voltage to the heated wire. This reduces power consumption. The output of the meter is a digital signal, with the pulse width related to the flow rate. One advantage of this type of meter is that the EFI computer does not need an analog to digital converter to acquire the data - it can use a digital counter.) 890301 -- _A Hot Wire Air Flow Meter for Intake Air Flow Measurement_,Nishimura, Yutaka; Ohyama, Yoshishige; et al., 1989, ISSN 0148-7191. (The authors are from Hitachi, Ltd. This paper "outlines the development status of the Hitachi hot wire air flow meter." Also covered are "approaches to improve response time" and "to avoid deterioration in the measurement accuracy caused by dirt deposits on the hot wire probe.") 890459 -- _Combined Boost Pressure and Knock Control System for S.I. Engines Including 3-D Maps for Control Parameters_, Rohde, Siegfried, and Philipp, Matthias, 1989, ISSN 0148-7191. (Reprinted from SP-780, _Power Boost: Light, Medium, and Heavy Duty Engines_. Authors are from Bosch. This paper discusses the Motronic EFI system with knock sensor and turbo boost pressure control; good info on control methods.) 900258 -- _Hot Wire Air Flow Meter for Engine Control Systems_, Takahashi, Ken; Tsuruoka, Shigeo; Nishimura, Yutaka; et al., 1990, ISSN 0148-7191. (The authors are from Hitachi Ltd. This paper discusses a new type of wire probe, resulting in improved response time.) 900259 -- _Advanced Design for Bypass Type of Hot-Wire Air Flow Meter_, Arai, Nobukatsu; Sekine, Yoshihito; et al., 1990, ISSN 0148-7191. (Reprinted from SP-805 - _Sensors and Actuators 1990_. Authors are from Hitachi. This paper discusses a bypass type MAF meter integrated into a throttle body.) 900488 -- _Combustion Knock Sensing: Sensor Selection and Application Issues_, Dues, Steven M.; Adams, Joseph M., Shinkle, George A., 1990, ISSN 0148-7191. (The authors are from Delco Remy Div., General Motors Corp. This paper discusses basic knock phenomena, sensor types, application issues, process flowchart, location selection, sensor selection criteria, sensor comparisons, popular misconceptions.) 900616 -- Mean Value Modelling of Spark Ignition Engines, by Hendricks and Sorenson, 1990. 900780 -- _On-Chip Realtime Operating System for the Engine Control System_, Matsubara, Shoji; Kuwahara, Takashi; Gerhard, F. Bruce; 1990, ISSN 0148-7191. (The authors are from NEC Electronics. Discusses the "NEC uPD78602 16-Bit Single-<a href="http://www.andysautosport.com/performance_chips.html">Chip</a> Microcomputer that incorporates a real-time operating system as firmware (alias Realtime Task Manager: RTM) as an example.") 910258 -- Discusses modeling intake manifold and fuel film dynamics. 910501 -- Sasayama, et al. Describes alternative methods of using O2 sensors 920289 Modeling, filtering, and closed loop control? 930352 -- Wang, et.al. Describes alternative methods of using O2 sensors 930856 -- Operating characteristics of Zirconia sensors. 940373 "Adaptive <a href="http://www.andysautosport.com/air_fuel_controllers.html">Air-Fuel</a> Ratio Control of a Spark-Ignition Engine" 940379 -- Describes a new pressure sensor that they use for misfire detection, knock control, ignition control, etc. I have a feeling that you may be seeing these in pass. cars in the not too distant future. Still some signal processing circuitry required but the price has to be better than a PCB or Kistler unit. 950531 -- Brialsford, et al. Describes alternative methods of using O2 sensors FISITA -- Adaptive Transient Air-Fuel Ratio Control to Minimize Gasoline Engine Emissions, by Beaumont, Noble, and Scarisbrick, 1992. HS3000 -- Complete specification of OBD-II -- Describes an experiment performed by the EPA wherein they discover that O2 sensors in fact do not sense O2 until they reach 800 degrees C. Until that point they measure H and CO. ----------------------------------------------------------------------- Parts ----------------------------------------------------------------------- ACH-04-08 Amp This is a 3-axis accelerometer (y-axis, z-axis, and rotational acceleration around z-axis) that is fully programmable. You can read only 1 axis at a time in either digital or analog format. y-axis sensitivity is 1.5 mV/g, z-axis is 12 mV/g, and rotational is 0.3 mV/rad/s^2. I don't have time to quote the entire data sheet but I think is has programmable gain (ie. ranges). I was wrong about the price: it is $30 (maybe I was thinking $10 per axis?). Oh yeah, this data sheet and price is preliminary. HIP9010 Harris Semiconductor An integrated knock sensor signal processor. This thing (HIP9010) is controlled by a microprocessor bus port, and does programmable gain, filtering, windowing and integration. It produces an analog output voltage for knock amplitude. MC3484-S4 Fuel injector driver. They cost about $4.50 each from Hamilton-Avnet, but you have to buy at least 40 or 50 at a time. LM1964 An amplifier designed especially for amplifying O2 sensor signals. It's in National's special purpose devices book (Linear 3). LM9044 Lambda Sensor Interface Amplifier Nat'l C LM1949 Injector Drive Controller SAMTEC makes QFP to PGC Adapter boards for a variety of QFP Packages. Chip Specific Adapters "SPEC" for a variety of Motorola and Intel Chips, SAMTEC phn 800 726-8329. CSP3000 -- Signal processor for automotive applications The Car Signal Processor (CSP3000) is a signal processor designed for use in automotive applications. 24 analog inputs and 8 PWM outputs represent the interfaces with the analog world. The digital, 12 bits wide I/O port and two serial bus interfaces permit the exchange of digital data within the application or between processors. FEATURES OF THE CSP: - 12 Bit RISC processor (FP) - 256 words of internal RAM (12 bit) - 2048 works of internal ROM (20 bit) - internal clock generator - 12 Bidirectional IO lines - 2 serial ports - up to 24 analog inputs - 8 PWM outputs - up to 24 digital inputs - all digital inputs with hysteresis - 2 independant RESET pins for FP and PWM system - PLCC 68 package - EMU version available in 132 pin LLCC package MC68332 -- CPU32 modular controller The MC68332 is one of a Motrola's family of modular architecture controller chips. The '332 contains the following modules: * CPU32, a 32bit M68000 style processor with all 68020 functionality except the bitfield operations. * TPU, a 16 bit RISC time processing unit that has 16 I/O pins and can independently perform all sorts of time functions such as PWM, period measurement, position synchronized pulse generation, missing pulse detection, etc (great for engine management). * QSM, a serial module that contains one standard asynchronous serial port and one synchronous port. * SIM, a system integration module that does chip selects, etc. * 2K of onboard static ram. 67F687 The 67F687 is a high performance MSICs ( Mixed Signal Integrated Circuit ) designed to work with a microprocessor in an engine management system. Using two sensor inputs (crank and cam), the 67F687 tracks engine position through one or two complete revolutions with a resolution of 0.25 degrees. Designed to be flexible, the 67F687 will accept a variety of sensor types and pulse patterns. It generates ignition and injection output pulses based on position and time parameters supplied by the host microprocessor, relieving it of many of the real time interrupt routines associated with these tasks. These outputs can directly drive power devices to actuate automotive ignition coils and fuel injectors. A sense input from each device allows individual diagnostics, short circuit protection and ignition coil current limiting. A timer, which measures coil charge time at the ignition sense inputs, enhances closed loop dwell control. Communication with a host microprocessor is through a parallel data and address bus. A general purpose parallel I/O port offers level sensitive input and output capability, in addition to edge detect inputs and PWM outputs. Silicon Systems Automotive Products 14351 Myford Road Tustin, CA 92680 USA Attn: Tony Anderson Electro Corp. 1845 - 57th Street Sarasota, FL 34243 voice: 813-355-8411 fax: 813-355-3120 A complete line of sensors. MC3334 Ignition controller chip. It's an 8-pin DIP that uses a sensing capacitor to determine if the coil was completely charged for the last spark. It adjusts the dwell for the next spark accordingly. CS-452 and CS-453 Injector drivers In the Cherry Semiconductor Automotive IC Data Book (1992), they list an "injector solenoid driver." The part number is CS-452 (2.4A peak current), and the CS-453 (4.4 A peak current). These parts appear to be equivalents to the Motorola MC3484S2-2 and MC3484S4-2, respectively. The pinout and package are the same. Comparison of the specs shows identical performance. I have no idea what these cost, or if they are still available. HIP 7030A0 and HIP7020 OBD-II/J1850 drivers Harris has a complete and inexpensive line of OBD_II SAE J1850 comm protocol IC's. The protocols are too complex for a mail post (unless I had a week to write...) but the SAE publication HS-3000 is the complete shebang...One of the harris IC's is the HIP7030A0... It is a 68HC05 cpu with SENDEC, crc generation etc... It only requires code and the HIP7020 Bus tranceiver chip. CA3228 Harris Semiconductor -- A complete DIY cruise control less switches and servo. Requires a bare minimum of external components. MGP20N40CL The Motorola MGP20N40CL is a nice IGBT for ignition coil drive. It has internal clamping diodes for voltage protection (400V) and can handle 20 amps. In practice, with peak coil currents of 10A, it only needs a small heat sink. You can drive it directly from a 5V CMOS output. ----------------------------------------------------------------------- Software ----------------------------------------------------------------------- PADS -- Circuit layout software. Has all the symbols, 68000, 8031, 80x86, TTL, CMOS, etc. It seems easy to add to this as well. Outputs Gerber, Postscript, etc. Got the copy I have off a CDROM. Walnut Creek Simtel 10/93 collection. Anyway, try ftp.uu.net, wuarchive.wustl.edu, ftp.funet.fi etc. The directory at ftp.uu.net should be /system/msdos/simtel/cad. The files are padslib.zip, padslog.zip, padspcb.zip. Dunno what the versions are. RTEMS -- Real time OS Developed by the Army, see the www page at: http://lancelot.gcs.redstone.army.mil/rtems.html It's now available for both efi68k and efi332. GCC -- DOS hosted cross compiler for 68000 series CPUs There are now binaries (and the changed source files for anyone interested) available via anon. ftp. The binaries are gcc 2.6.0 for djgpp (msdos) host and 68000 family embedded target. The ftp address is: ftp.lysator.liu.se in directory /pub/msdos/gnu/gcc-dos-m68k ----------------------------------------------------------------------- Definitions ----------------------------------------------------------------------- ADC = Analog to Digital Converter A/D = Analog to Digital ALDL -- Assembly Line Diagnostic Link. The connector under the dash on GM cars. It can be used to dump diagnostic information from the ECM, but requires special equipment to use. BP = Barometric Pressure BTC = Bottom Dead Center CAN = Controller Area Network. A proposed network protocol for automotive use outside the US. The US proposal is SAE standard J1850, aka OBD CTS -- Coolant Temp Sensor CYA = Cover Your Ass DAC = Digital to Analog Converter A/F = Air Fuel Ratio DIS = DistributorLess Ignition EGT = Exhaust Gas Temperature ECM -- Engine Control Module? It's the engine management computer. ECU = Electronic Control Unit (?) Same as ECM IAC -- Idle Air Control motor. A stepper motor controlled by the ECM. It determines how much air gets through to the engine when the throttle is at idle. The computer controls it to maintain a constant idle. MAF -- Mass Air Flow. An FI technique where the mass of air flowing into the intake is directly measured via a hot wire , rotating vane, or hinged flap. The computer reads this value and injects the proper amount of fuel. MAP -- Manifold Air Pressure. The air pressure in the intake. MAT = Manifold Air Temp sensor MCU = MicroController Unit (eg. 68HC11) MPFI -- Multi Port Fuel Injection. One (or more) injectors per cylinder. OBD = On Board Diagnostics. Mandated in the US, this forces auto manufacturers to use common protocols and connectors for automotive diagnostics. OEM = Original Equipment Manufacturer. PLCC = Plastic Leadless Chip Carrier PWM = Pulse Width Modulator SAE = Society of Automotive Engineers SBC -- Single Board Computer or Small Block Chevy SD -- Speed density. An FI technique where the amount of air entering the engine is calculated from engine RPM, MAP, and a pre-calculated volumetric efficiency for the engine. SNAFU = Situation Normal - All F*ck'd Up SOL = Shit Out of Luck TBI = Throttle Body Injection. One or more injectors located at the throttle body. Basically a more efficient carb. TPI = Tuned Port Intake TDC = Top Dead Center. Piston at the top of the cylinder TPS = Throttle Position Sensor. Tells the ECM how "open" the throttle is.
A Chemists View on Octane and Gasoline Brands
From Tom Johnson, tjohnson@FLEX.NET
Someone in the octane thread asked for a chemist's view on the subject, so here's mine. However, first a view necessities and background:
Credentials:
Ph.D. Organic chemist, 21 years as a practising chemist, 28
US patents (many on gasoline additves), work for a major oil company that
is a leading (by volume) retailer of gasoline in the world. I've had
engine tests (meaning an engine on a fixed engine stand run by a computer)
and road tests (meaning cars driven by humans -- some on a course, some
not) run on gasoline additives I've invented (while employed at the oil
company). These additives have been tested in the US, England, and France
under a variety of conditions. Many of my additives have also been tested
in the BMW test (10,000 miles). I'm still employed by said oil company.
Disclaimers:
The views expressed here are my own and not the company I
work for (which is why I don't mention the company, although I realize any
enterprising person could easily find out).
Copyright:
This entire note is copyrighted by the author. Participants in
this mail group may store and make one copy for their own use.
Participants may refer to, copy, send, and re-send to particpants of this
mail group and post or re-post sections of this note as long as this
copyright notice is attached. Except for these specific exceptions, this
note may not be copied, quoted, or transmitted in any form for profit or
non-profit, or used for any type of publication without written permission
from the author.
Corvette:
Mine is a 1979 that is on its second trip through the odometer
(and its second engine, and third interior). I've owned it approximately
12 years, love it, and may never get rid of it.
Octane:
I've seen many consummer magazines tell their readers that they
are wasting money to buy a higher octane gasoline if their car doesn't
knock. If octane were not related to any other feature of the gasoline, I
would agree. However, how companies get higher octane gasoline does make
it different than regular and mid-grade gasoline. So the question to me
then is, do these differences make a difference? The short answer is what
do I use, and I use regular in all my cars and my truck. I use premium in
my Corvette. Why? Because as any Corvette enthusiast (to separate us from
people who merely own one -- no flames, please) knows, a Corvette is not a
car, it's an experience. If you want to know the long answer keep reading.
Base gasoline:
Crude oil differs depending on where it's from, and
consequently, what comes out of it when it's refined also differs. There
are books on the subject and I can't possibly do the subject justice here.
As the oil differs, what is available for blending and cutting is
different. In the end, however, the refiner has to make economic choices,
based on what's available to him from the oil he is refining, on how to get
the required octane to sell (as well as meet MANY other criteria that make
gasoline, gasoline -- again I can't do justice to it here). What I
generally (but not exclusively) see is that BASE (no additve added to it --
you can't buy this, it isn't offered for sale) premium gasoline leaves less
deposits behind than other grades. There are certain types of molecules in
regular and mid-grade BASE gasolines that simply do not exist in premium
gasoline that cause much of this. Additives (see definition below) are
added to the gasoline to help get rid of these deposits, and modern
additives do a marvelous job of this. What you buy is additized gasoline.
Blending components vs additives:
MTBE (methyl tertiary butyl ether --
this is ether) and ethanol are blending components, not additives.
However, you'll see them called additives in many places by many people.
Blending components are part of base gasoline. The simplest
differentiation between an additve and a blending component is that the
former are added in ppm (parts-per-million) levels; whereas, the latter are
added in percentage quantities.
Brand of gasoline:
Some of you probably know this, others may be shocked
by it. Oil companies swap base gasoline all the time. Let's say I have a
refinery in Houston and you have one in Dallas. It makes little sense for
me to truck my Houston gasoline to Dallas and for you to truck your
gasoline from Dallas to Houston when gasoline is a commodity product. So,
I let you draw 100,000 gallons of base gasoline from my storage tank in
Houston for your Houston gas stations, and you let me draw 100,000 gallons
of base gasoline from your Dallas holding tanks for my Dallas gas stations.
That way, we both save on shipping. Yup, Texaco gasoline may have come
from a Shell refinery and vice-versa. At a gasoline terminal you may see
trucks from up to six different companies all loading at the SAME terminal
(that for example may be supplied exclusively by Shell). What comes next,
however, is what makes Texaco Texaco and Shell Shell. Additive. Each
company has its own additive and adds it to the base gasoline. So while
the base gasoline may be the same, the additive is different, and hence the
brand of gasoline you use is different because of the additive, not the
base gasoline.
Which additive is better?:
Given the above discourse, it's obvious that we
all want the gasoline with the best additive. Unfortunately, it's not that
simple. Additves respond differently in different base gasolines (even of
the same grade). Also, some additves work better with gasolines used in a
carbureted car vs one that uses fuel injection. On a practical level,
additives are going to be developed today for today's cars -- meaning fuel
injected cars. For Corvette owners who have carbureted Vettes (like me),
this is unfortunate. Carbureted engines leave a LOT more deposits behind
than fuel injected cars. From a regulatory stand point, California was the
first to call for all gasolines to pass the BMW test (port-fuel-injected
engine) in all grades of gasoline. Like all regulations, this one had
various massages put to it, but the net effect was that all oil companies
went to work developing additives that are a LOT better today than 10 years
ago AND they are used in all grades (not just premium -- hence the argument
to use premium to get a better additive went out the window).
Insider's trick on gasoline additives:
No matter what you do or what you
drive, this trick will help you keep down deposits inside your engine. You
see, additives themselves will make deposits and/or create a deposit that
is different from the one made by base gasoline alone. If you think about
this for a moment, you'll come to realize that your engine will build some
kind of deposit based upon what additive you are using. Yes, it will build
at a slower rate, but it will build deposits. At some level this will
taper off (but this is maximum deposits and what Corvette owner wants
that!). So what do you do? Simple, switch to a different brand of
gasoline (this will almost assure you of getting a different additive but
not always. Some companies buy additives from other companies, so it could
be the same. More on this later). What this will do, is the new additve
will look at the deposit formed from the old additive as foreign and begin
removing it. Now after 5000 miles, you'll be rid of this deposit but
you'll have a new one from your most recent additive, so switch back and
start the process all over again. As an analogy, this is like building an
immune response to an anti-biotic, so your doctor gives you a new one. I
know of absolutely no additive that will work as well as switching back and
forth between additives. On a molecular level this makes perfect sense.
So what's a Vette owner to do?:
(1) Whether you buy regular, mid-grade, or premium, use one brand for
about 5000 miles, then switch to another brand for 5000 miles. I use
Shell, then Chevron, then Exxon, then back to Shell, etc. (this is not an
endorsement). These companies have historically had there own additive
research groups/companies, so they'll likely use their own additive and not
something they bought from each other. It is completely posible, however,
to use a sequence like Amoco, Shell, Texaco and still come out fine.
(Again these are not endorsements). I use three companies and 5000 miles
based on what I've observed working in the research area. 7,000 miles and
two different brands will still do wonders. As an aside, it takes most
vehicles 7-13,000 miles to build their maximum deposit levels.
(2) If your Vette is carbureted or TBI, buy premium. These fuel-delivery
systems build deposits rapidly and to much much higher levels than PFI
(port fuel injection) systems You need every edge you can get (if you're
an enthusiast). If I had a PFI Vette I'd still buy premium, but must tell
you the effect will not be like in the carbureted version.
Part 2, Questions Answered
I've received a number of questions and many kind words (Thanks!). I thought I'd handle some of the repeated questions here.
Can I change between two different gasoline brands on every fill and get
the same effect as switching brands at 5000 miles?
It's obvious from the responses and questions I've gotten on this
that there's a lot of Brand loyalty out there (and the oil companies love
you for it) and folks can't bear to be without their favorite gasoline for
5000 miles. Consequently I'll try to answer this question and at the same
time try to help people stick with their favorite gasoline most of the time.
(1) I use the 5000 mile method because it works and because it's easy to remember. Every time the odometer hits a number divisible by 5, I switch. In reality, most of the deposit removal is accomplished in the first 1000 miles of new gas (maybe 3-5 tankfuls depending on how low you go before re-filling and what kind of mileage you get). 50% reduction in deposits is not unheard of over this time frame. You may get 10-20% more in the next 1000 miles, then you start to rebuild (actualy add to the residual deposits that remain). SO, if you want, you can go 5000 miles on your favorite brand, 1000 miles on your second favorite, and then go back again. For me, this is a pain in the butt. I'd have to remember to change brands at 5,6,11,12,17,18,23,24,000, etc miles. I'd rather just look at my odometer and say, "Hey, 55,000 miles. Time to change." As the saying goes, different strokes for different folks. Both methods will work a lot better than never changing brands (And again, I ONLY do this with my Vette. All my other vehicles get regular from where ever I happen to stop (although I only use a major brand).
(2) If you switch between Brand X and Y between fills, you're really just creating a new additve combination. As we don't run our tanks completely dry between fillups, you'd always have a residual amount of both additives in your tank at all times. This would likely create a different deposit than either X or Y by itself. By analogy this would be like taking a bucket of yellow paint and throwing it against a wall. The wall is yellow and represents deposits from additive X. Let's say your bucket is 1/4 full (like your gas tank) with yellow paint. Now you fill the bucket with blue paint (additive Y) and mix. The bucket now contains green paint. You throw it at the wall and the wall is now green. Next, take your 1/4 full bucket of green paint and fill it with yellow paint (X). You're gonna still have green paint, perhaps a different shade of green, but it is definitely not yellow and it's definitely not blue. If you repeat all these steps over and over, the wall will be green. It will not be yellow (X) or blue (Y). So all that you have done is create a new color (deposit type). If you want to change the color on the wall (other than shades of green), you'll have to switch to a new color (red?) and toss it at the wall several times before you can't see any green or have any green bleeding through your red. Of course with real deposits, we're removing them and changing what's left, not just covering them up, but hopefully this paint color analogy helps explain this.
Is gasoline dyed?
Many, many years ago it was. I'm not aware of any gas being dyed
now. (Anybody remember Purple Martin high octane from the 60s? It looked
like grape Kool Aid and was quite a marketing gimmick)
What gives gasoline color?
Many different things. Some bad, like PNAs (polynuclear aromatics)
mentioned by Tracy, some not so bad. A lot of companies add anti-oxidants
to keep down gum formation and that also helps color. However, a lot of
gas stations are re-filled daily, so storage time isn't a problem. Premium
is generally less colored due to how it's made (little or no PNAs, etc).
Regular and midgrade are made from many things and generally have some
color. I'd be concerned with any gas that was bright yellow or premium
that was anything other than white or faintly yellow.
What about fuel injector additives?
Give the money to charity where it'll do some good; your fuel injectors
will never know the difference. Other than a narrow window in 86-87 where
some fuel injectors fouled, the modern (meaning post 87) injectors are of a
design that won't foul unless you put some really old rotten gas through
them. We had one guy in our group whose job it was to test our gas and
competitors brands for injector fouling. He couldn't do it with '88 and
newer injectors (with any brand of gas!). I mean he couldn't even get
these injectors to foul a little. The only way he could run fouling tests
was to buy a specific type and brand of pre-88 injectors (and he had a
really hard time finding them. He bought up all he could find. -- Sorry
can't tell you type and brand, but I doubt any of you have them). If you
store your Vette over the winter and start it on gas that's been in the
tank all those months, you will likely foul your injectors some. But if
you can get it started and put fresh gas in it, all the additive packages
(in the gas you buy) I've seen to date will clean the injectors in 1-2 tanks.
What about valve cleaner additives?
Can't recommend any specific brands, but there's one I know of that you add
to your gas tank and it works pretty well. There is a downside to what is
essentialy adding a large overdose of additve to your gas, however.
Additives are heavy molecules and as such they tend to end up in your oil.
If you use this method, you will add a greater than normal amount of
additive to your oil and that will affect its properties. The way around
this is to use the valve cleaner additive and then change your oil after
you're done with that tank of gas. In other words do this only when you're
near an oil change. There is another possibility, and that's that the
valve cleaner additive you use is the same as what's in the gas you use.
In which case it will do little good.
Overall, I'd just buy gas from a major brand, and then switch at 5000 miles
(or use the 5000 and 1000 mile method). If you have to store your Vette
(thank God I live in Texas), leave as little gas in it as possible.
Tom
Common Transmission Gear Ratios
MANUAL TRANSMISSIONS:
Richmond Gear T10 4-spd manual
2.43, 1.61, 1.23, 1.0 PN: 13040000070
2.64, 1.75, 1.34, 1.0 PN: 13040000069
2.64, 1.60, 1.23, 1.0 PN: 7021090
2.88, 1.91, 1.33, 1.0 PN: 13040000072
Richmond Gear R.O.D. (Richmond OverDrive) 6-spd manual
3.27, 2.13, 1.57, 1.23, 1.09, 0.76
4.06, 2.22, 1.57, 1.23, 1.09, 0.81 (optional 0.88)
3.01, 1.88, 1.46, 1.19, 1.09, 0.62
Richmond Gear (Doug Nash) 5-spd manual
3.27, 2.14, 1.57, 1.23, 1.00
Borg Warner T56 6-spd manual
3.36, 2.07, 1.35, 1.00, 0.80, 0.62
Ford Mustang 5.0l 5-spd manual:
1986-1988
3.35, 1.93, 1.29, 1.00, 0.68
1989-1994 5-spd manual
3.35, 1.99, 1.33, 1.00, 0.68
Borg Warner Close Ratio T-5
2.95, 1.94, 1.34, 1.00, 0.63 (0.80 optional)
Tremec 5-spd manual (aftermarket)
3.27, 1.98, 1.34, 1.00, 0.68 Model: 3550
3.18, 2.06, 1.39, 1.00, 0.65 Model: 3750S
1987 VW GTI 16V 5-spd manual
3.45, 2.12, 1.44, 1.13, 0.91
ZF 6-spd manual (Used in '93-up Corvettes, including ZR-1)
2.68, 1.80, 1.31, 1.00, 0.75, 0.50
AUTOMATIC TRANSMISSIONS:
PowerGlide 2-spd Automatic
1.82, 1.00
1.76, 1.00
Ford C-4 3-spd automatic
2.46, 1.46, 1.0
Ford C-6 3-spd automatic
2.46, 1.46, 1.0
Ford AOD 4-spd automatic
2.40, 1.47, 1.00, 0.67
AOD Wide Ratio 4-spd Automatic
2.84, 1.55, 1.00, 0.67
Ford AL4D (1987-1989) 4-spd automatic
2.47, 1.47, 1.00, 0.75
Ford E4OD 4-spd electronic automatic
2.71, 1.53, 1.00, 0.71
TH-700R4 (1991 Chevrolet)
3.06, 1.63, 1.00, 0.70 rev-2.29
200-4R (Grand National transmission)
2.74, 1.57, 1.00, 0.674
0.........1.........2.........3.........4.........5.........6.........7. Frequently asked questions about R-12 (Freon (c)) and alternatives. This version updated 6-19-96 This is my first attempt at a FAQ, so bear with me. You can reach me via email at sravet@bangate.compaq.com if you want to comment, make suggestions, etc. This FAQ can now be found on the VetteNet home page, http://www.dcc.edu/vettenet. The URL directly to the FAQ is http://www.dcc.edu/vettenet/acfaq.txt Parts of this document are short, because I don't necessarily know the whole answer to the question. If you know something about one of these questions, feel free to email me with the information. If you have suggestions for additional questions and answers, feel free to email me. I will acknowledge up front that I view a lot of environmental regulation as extremely suspicious. That viewpoint probably comes across in this document. The point is, I welcome any comments about this document, pro or con, as long as they contain factual data. People who are long on opinion but short on fact need not bother writing to me. The EPA maintains a nice page listing the status of all refrigerants that have been submitted for use in mobile systems. So I am removing this information from the FAQ, as it was hard to keep updated anyway. See their page at http://www.epa.gov/ozone/title6/snap/macssubs.html At this site, the EPA also provides a classified ad service for speculators buying and selling R-12. The EPA notes that prices of R-12 have skyrocketed lately, they suppose that the following might be reasons: o the end of production of R-12 on January 1, 1996. o supplies being withheld for future years. o lack of information preventing buyers from finding sellers. o difficulties in moving existing stocks around the US. What they forgot to include were the following: o $5.45/lb federal tax on R-12 in 1995, increasing each year. o Government bans always create high prices/black markets. DISCLAIMER: ----------------------------------------------------------------------- Please note that while I have tried to make this document as correct as possible, there are inevetably going to be some errors. Something that is legal today may very well not be legal tomorrow, and you are urged to call the EPA and your state to verify the legality of any A/C service you wish to perform. Some states have their own restrictions in addition to the EPA guidelines. The EPA has an ozone hotline (run at a profit by a private company, of course.) It can be reached at 1-800- 296-1996. Sometimes they have the correct answers to questions. Some procedures and products in this document may be illegal and/or dangerous depending on the context in which they are used. Specifically, replacing R-12 with an unapproved substance is illegal and can get you up to a $25,000 fine, with a $10,000 reward for whoever turns you in. That’s nice, huh? This purpose of this document is expressly stated to be a source of facts. It is not intended in any way to encourage violating the law or other civil disobedience. This FAQ is a source of facts on R-12, and other alternatives for mobile A/C systems. It is not a tutorial on automotive A/C service. Fixing your car's A/C is no more difficult and no more dangerous than changing plugs, replacing a distributor, or any other type of service that people typically do themselves to save money. You do, however, need to have the proper tools and knowledge to work on A/C. Purchase the factory service manual for your car. You will be better off for having spent the money. Issues discussed within this document apply to the United States. Most R-12 using/producing countries have banned R-12 via the Montreal Protocol, but the substitutes discussed herein may or may not be legal for other countries. Any opinions herein are mine, and although they are (or should be :-) widespread, they do not represent the opinions of anyone but myself. ----------------------------------------------------------------------- Table of Contents: 1) What is R-406a (aka GHG Refrigerant 12 substitute)? 2) What is GHG-X4? 3) What is HC-12a? 4) What is OZ-12? 5) What is R-134a? 6) What is SUVA? 7) How does R-12 hurt the ozone layer? 8) It's a patent scam by DuPont! 9) What about flammability? 10) Who is MACS? 11) How do the EPA regulations affect the A/C DIYer? 12) Numbers and addresses of the players. 13) Where can I get more infomation about this stuff? 14) How can I make my own recovery equipment? 15) What is that white vapor coming out of the vent? 16) What is the two step upgrade? 17) How could I make an HC based replacement if I wanted to? Appendix A: People ----------------------------------------------------------------------- 1) What is R-406a? ----------------------------------------------------------------------- Newsflash: George Goble has filed for EPA approval on R-406a in mobile applications. Normally, it becomes legal to sell a refrigerant 90 days after application, even if there is no word on approval from the EPA. This is to encourage the EPA to act quickly since any refrigerant will be legal to sell by default after 90 days. The EPA has REVOKED this in the case of R-406a, since it is "weakly flammable" in the worst leakage case. In this case weakly flammable means that it can be ignited by a flame, but will not actually sustain a flame on it's own. It is self- extinguishing. This rule was passed in July ‘95. George made his application in June ‘95, but the EPA is still applying the rule. This means that R-406a will have to successfully complete EPA approval before it will be legal to sell. You can voice you opinion on this to the EPA. The EPA web site is listed at the end of this document, and they have a feedback page for comments. EPA certification typically takes a year, so look for R-406a to be available in the summer of ‘96. R-406a, formerly known as GHG R-12 substitute, is an ozone friendlier, R-12 compatible drop in refrigerant. It was invented by George Goble, who has a couple of patents on it. (ghg@ecn.purdue.edu, http://ghg.ecn.purdue.edu/). It is a three part blend of 55% HCFC-22, 41% HCFC-142b, and 4% isobutane. It is compatible with the rubber seals and hoses, and with the mineral oils used in R-12 systems. In addition, it offers somewhat better performance than R-12. It is 95% less ozone depleting than R-12. (ODP of .05 vs. 1.0 for R-12). R-406a was initially tested in August 1990 in three cars. By 1992, approximately 500 vehicles had this blend installed. Out of 500 cars, only one car suffered A/C system failure. Analysis showed that the Teflon piston rings had failed, which is a common failure mode for this particular compressor according to local mechanics. R-406A may leak through "nitrile rubber" hoses, mostly found in foreign made cars, and port-of-entry add-on A/C systems. Most American cars, have used "barrier hoses" for years, and these work fine. All replacement hoses are of the "barrier" type now. R-406a yielded a 4 to 13 degree F decrease in discharge air temperature over that of CFC-12 at ambient temperatures over 80 degrees F. Compressor discharge temperatures were also approximately 20 degrees F higher than comparable R-12 systems, but still low enough to prevent refrigerant or oil breakdown. R-406a has been tested with CRYO-SILANE, a commercial A/C system sealant and was determined to be compatible. Cryo-Silane is effective at stopping leaks that fall into the three week to one year leak rate. Since R-406a is a blend, a system should be evacuated before filling. The three components have different leak rates, so topping off would result in altered concentrations. In addition, R-406A (and all other blends) have to be charged as a LIQUID (yes, on the low-side, but bottle upside-down) because each substance has a different vapor pressure (thus different rate of release as a gas). But, you have to be careful to monitor the suction pressure and ensure that the flow from the can is gradual. If it gets above a certain point, you'll be sucking liquid and the compressor will fail. This mix does contain Iso-butane, which is required to disolve the mineral oil, but has been shown to be non-flammable in this blend, or weakly flammable in the worst case scenario. It has been classified as A1/A2 by ASHRAE. Topping off could result in higher concentrations of isobutane, which is why this practice should be avoided. Several things should be noted here, namely that _any_ refrigerant can be "flammable" if it contains dissolved oil and a rapid release occurs. The oil atomizes and can be ignited. In addition, any refrigerant that contains hydrogen atoms (HCFCs) can be flammable when mixed with large amounts of air under pressure. This includes R-406a, the EPA approved R-134a, R- 22, etc. For this reason these refrigerants should not be mixed with air under pressure. See the WWW page: http://worldserver.com/R-406A/ R-406a can be purchased from: Monroe Air Tech Bloomington, IN 1-800-424-3836. IT IS CURRENTLY ILLEGAL TO USE R-406a AS A REPLACEMENT FOR R-12 IN MOBILE SYSTEMS ----------------------------------------------------------------------- 2) What is GHG-X4? ----------------------------------------------------------------------- GHG-X4 is a reformulated version of R-406a. GHG-X4 is nonflammable as formulated, and does not become flammable after leaking and recharging (the refrigerant by itself). R-406a, upon which this blend is based, is classified as non-flammable in it’s original blend, and weakly flammable after the worst case leakage. Under the 1990 Clean Air Act as amended, GHG-X4 is legal to sell in the US for automotive and stationary A/C and refrigeration systems starting Jan 17, 1996. Under the EPA SNAP process, GHG-X4 will be evaluated and either listed as "acceptable" or "unacceptable" for various end uses. If declared "unacceptable", then sale must stop. If declared "acceptable", it may be continued to be sold, but probably with "restrictions" attached, like unique threaded fittings which go onto cars, and never come off, pressure cutout switches, etc.. GHG-X4 is made from the following components and weight percentages: R-600a 4% (R-600a is isobutane - carries oil) R-142b 16.5% R-124 28.5 R-22 51% GHG-X4 works with mineral or AB oils found in R-12 systems, no retrofit needed. However, old "nitrile" rubber hoses should be changed to the newer "barrier" (nylon lined) hoses as R-12 and GHG-X4 leak faster thru nitrile hoses. Most American cars have used barrier hoses for years, so no change is needed. Do not use with "PAG" or "POE" oils (R-134a systems). Many times it will work in R-500 systems unmodified, TXV systems might need a new "powerhead" on the TXV. R-500 cap tube systems should be ok. We have even had customers (with R-406A) "retrofit" R-502 systems (refrig transport) to R-406A which is very similar to GHG-X4 by only changing the expansion valve.. This should not work, but we have several customers who swear on a stack of Bibles that it works. I would expect only 50% of original R-502 capacity. Cooling performance is equal to or better than R-12. (similar to R-406A) GHG-X4 was unveiled Jan 18, 1996 at the MACS meeting/show (Mobile Air Conditioning Society) booth 106 in Orlando, FL. Call 1-800-424-3836 (Monroe Air Tech) or 1-800-669-5730 (McMullen Oil Products) or see the WWW page. The WWW page has a more extensive GHG-X4 FAQ. Available in 25 lb cylinders (equiv to 30 lbs of R-12) or in 9.6 oz cans (equiv to 12oz R-12). Contains EPA class II substances (HCFCs), and must be recovered and not vented to the atmosphere. Currently marketed under the name "AutoFrost" and "Chillit". http://worldserver.com/GHG-X4 IT IS CURRENTLY LEGAL TO USE GHG-X4 AS A REPLACEMENT FOR R-12 IN MOBILE SYSTEMS ----------------------------------------------------------------------- 3) What is HC-12a? ----------------------------------------------------------------------- HC-12a is manufactured by OZ Technology as a direct R-12 and R-134a replacement requiring no retrofit. It is a second generation product that replaces OZ-12. It is a patented hydrocarbon blend of unknown composition. It has 0 ODP and 8 GWP. It is compatible with any system containing R-12 or R-134a, including both mineral and synthetic oils, rubbers, metals, etc. It is up to 30% more efficient than R-12, which reduces load on the compressor and engine. Since it is a hydrocarbon blend, it is flammable. It has had a strong odor added to help identify leaking systems. DOE studies have shown that the risk of HC based refrigerants in mobile A/C units is negligible. The EPA banned it for use in mobile applications on June 2, 1995. The ban will take effect 30 days after publication in the Federal Register, which should be mid-July 1995. Approval was removed due to flammability concerns. OZ technology has not done a risk assessment to determine if there is a flammability hazard. IT IS CURRENTLY ILLEGAL TO USE HC-12a AS A REPLACEMENT FOR R-12 IN MOBILE SYSTEMS ----------------------------------------------------------------------- 4) What is OZ-12? ----------------------------------------------------------------------- OZ-12 was the first-generation R-12 replacement from OZ Technology. It is a hydrocarbon based refrigerant of unknown composition. It has been supplanted by HC-12a. It has been banned by the EPA for over a year due to flammability concerns. Report EA94-006 from DOT Auto safety hotline IT IS CURRENTLY ILLEGAL TO USE OZ-12a AS A REPLACEMENT FOR R-12 IN MOBILE SYSTEMS ----------------------------------------------------------------------- 5) What is R-134a? ----------------------------------------------------------------------- R-134a is the current replacement for R-12. Most new cars manufactured now have R-134a in their air conditioning systems, and all manufacturers plan to move solely to R-134a by the end of 1995. It is a retrofit rather than a replacement, as it requires some parts to be replaced before it can be placed into an R-12 system. R-134a is not compatible with the mineral oil used in R-12 systems, and uses a PAG (polyalkylene glycol) based oil instead. This oil is not compatible with the rubbers typically used in an R-12 system, so at a minimum all O rings and hoses must be replaced. In addition, R-134a has 20-30% less cooling capacity than R-12. Newer systems are designed with this in mind, but older systems just will not provide as much cooling capacity if they are converted to R-134a. In addition, R-134a will react with the aluminum chlorides left behind fron R-12 and form acids that eat at system components. These chlorides form on the surface of aluminum parts that are exposed to R-12. There are other problems with the oils used with R-134a. PAG oils may be destroyed from residual aluminum chloride coating the insides of pipes, etc, left over from when R-12 was in the system. These chlorides cannot be flushed out and are not present in "new cars". "Ester oils" (POE) are more tolerant of the chlorides, but are still 10X more moisture sensitive than R-12 mineral oil. PAG oil is about 100X more moisture sensitive. Ester oils have less lubricity than PAG oils. R-134a is flammable when mixed with air and placed under pressure, as are all HFC refrigerants, including R-406a, R-22, and others. PAG based oils are skin irritants and require impervious gloves to be worn when handling. R-134a can irritate the eyes, nose and throat. Exposure to R-134a has been shown to cause benign tumors in lab animals, under the non-realistic conditions of 5% atmospheric content over 2 years. Contrast this with R-12 and mineral oil, which are known safe under all conditions. R-134a currently does not require a license to purchase, but the EPA is considering requiring one. The initial rule will be published in August 1995. 90 days of public comment will be accepted, then the final rule will be published in November 1995. IT IS CURRENTLY LEGAL TO USE r-134A AS A REPLACEMENT FOR R-12 IN MOBILE SYSTEMS ----------------------------------------------------------------------- 6) What is SUVA? ----------------------------------------------------------------------- "SUVA" is DuPont's name for the family of new refrigerants. Seems that "Freon" (their current family of refrigerants) has a bad stigma attached to it now (Ozone layer). HFC-134a has a new "Suva" designation as well. DuPont has also announced SUVA MP-36 and -39 which are "almost dropins" for R-12 in automotive A/C. They are blends of R-22/R-152a/R-124 which closely simulate the temp/pressure curve of R-12. I have heard that one will need to change out the oil (need to use alkyl-benzene oil instead of mineral oil) and to use a new drier with XH-9 dessicant instead of the standard XH-5 dessicant (the R-152a attacks XH-5). SUVA is also the capitol of Fiji. ----------------------------------------------------------------------- 7) How does R-12 hurt the ozone layer? ----------------------------------------------------------------------- There are different wavelengths of UV called UVC and UVB. UVC is higher in energy (shorter wavelength) than UVB. Oxygen absorbs UVC, and ozone absorbs UVB. It is true that normal molecular oxygen absorbs UVC, and it is also true that it's not likely that UVC levels will climb because of ozone depletion. Current theory holds that chloro-fluoro-carbons (CFCs), once released, work their way into the upper atmosphere (stratosphere), where the chlorine atom is stripped from the CFC by the ultraviolet light. The chlorine atom then reacts with the naturally occurring ozone and changes it into normal oxygen. The chlorine is a catalyst in this reaction, which means that it enables the reaction to take place, without actually being used in the reaction. The chemical reactions that form and deplete the ozone are: Ozone forming (good) (1) O2 + UVC -> O + O (UV is ultraviolet light) (2) O2 + O -> O3 Ozone depleting (good) (1) O3 + UVB -> O2 + O (This reaction protects us from UVB) Ozone depleting (bad) (1) Cl + O3 -> ClO + O2 (2) ClO + O -> O2 + Cl Notice that after both the depletion reactions occur, the chlorine atom that started the whole thing is still hanging around to cause problems. This is why the CFCs are bad for the ozone. The chlorines cause the ozone to be destroyed, but aren't used up in the process. Other references on ozone are: Description of how chlorine affects the stratosphere http://icair.iac.org.nz/ozone/ozone.html Greenpeace Ozone crisis page http://www.cyberstore.ca/greenpeace/ozone/ozonehome.html There is a very good FAQ on ozone depletion posted periodically to news.answers. It is very readable and provides much more information than I have provided here. It is also available online at: http://www.cis.ohio-state.edu/text/faq/usenet/ozone-depletion/top.html Ozone Depletion Thematic Guide" produced by CIESIN: http://www.ciesin.org/TG/OZ/oz-home.html "US EPA Stratospheric Ozone Home Page" http://www.epa.gov/docs/ozone/ ----------------------------------------------------------------------- 8) It's a patent scam by DuPont! ----------------------------------------------------------------------- No it's not. R-12 was invented in the 1930s. The patent is long gone. ----------------------------------------------------------------------- 9) What about flammability? ----------------------------------------------------------------------- Most of the proposed drop-in alternatives for R-12 contain flammable materials. In November of 1991, the DOE commissioned a preliminary study of the risks involved. The conclusion of the report is that the risk of fire and/or explosion is very remote. The full text if available from NTIS. I quote relevant portions of the document below: "Non-inert Refrigerant Study for Automotive applications" Prepared for US Dept of Energy by Arthur D Little John Dieckmann Jeffrey Bentley Page 36 "The event of most concern involve a rapid release of refrigerant into the engine or occupant compartment. Vehicle crashes are the only likely source of a significant number of accidental releases." "The risk of injury from leaks into the occupant compartment is likely to be very small with current designes because 1) the interior A/C components are robust and well isolated from front/side crashes; 2) no credible ignition sources were found _inside_ the occupant compartment; 3) window blowout is predicted to occur before explosive overpressures reach the level required for injury; and 4) the thermal pulse from an explosive event would have insufficient energy to cause life threatening injuries. With a conventional A/C system, ... the risk of refrigerant release and ignition in the occupant compartment appears to be very small, approximately 3x10^7 such incidents per automobile, per year. With approximately 140 million passenger vehicles in service, approximately 40 incidents per year would occur if no A/C system design changes were made. As discussed in section 6.3, we believe that this estimate may overstate the risk considerably, as no evidence was developed that indicates that evaporators and connecting lines within the passenger compatrment are damaged to the point of leakage in even the most severe collisions." "For engine compartment leaks in an A/C system of conventional design we estimate: - Engine refrigerant leakage will occur in a significant number (17%) of "towaway accidents." - Jet mixing and dispersion will limit the probability of formation of a flammable mixture in the vicinity of an ignition source. - Only high energy ignition sources (broken battery cables, overheated catalyst jacket) are likely to cause ignition - Explosive overpressures in the engine compartment will be limited below levels of concern (<<1 psi) due to venting out the bottom of the engine compartment. - Conventional systems will have an incidence of fire on the order of 14 to 50 per million vehicles resulting primarily from ignition of refrigerant while it is leaking." "With relatively minor redesign we estimate the annual incidence of engine compartment fire will be reduced to less that one fire per million cars." The authors do CYA by stating that the study is preliminary and more in- depth research is needed before flammable refrigerants become widespread. ----------------------------------------------------------------------- 10) Who is MACS? ----------------------------------------------------------------------- MACS is the group mostly responsible for the current state of affairs in mobile A/C. MACS stands for Mobile Air Conditioning Society. They are the group that petitioned the EPA to outlaw alternatives, in spite of the fact that the EPA admitted that there was no environmental reason to ban the alternatives. As if that wasn't enough, you now have to pay MACS for the privilege of buying the freon and alternatives that they were so successful at driving the price of up. Note that you need a license to purchase any sort of refrigerant these days. Here's how to get the your very own federal license to purchase refrigerants: 1: Send $20 to MACS. 2: In a couple days you'll get a test and study materials in the mail. Read the study guide (27 pages), take the test at your leisure (it's open book, but you can't get help from anyone else.) 3: Send the test back in. If you answered 21 of the 25 questions correctly, then you are smart enough to buy refrigerants and they will send you a license in 4-6 weeks. This test only covers EPA regulations. It is not intended to teach you anything about A/C systems. Duh, that makes sense. There are other companies as well, but I do not have any information on them. ----------------------------------------------------------------------- 11) How do the EPA regulations affect the A/C DIYer? ----------------------------------------------------------------------- The short answer is: Other than the need for an easily obtained license, and the 900% increase in the price of R-12, there is very little impact on the DIYer. "Topping off" known leaking systems is perfectly legal, although it is logically inconsistent with the EPAs stated purpose. First, there has been some comment on the "service for consideration" loophole. This clause is only in, and only applies to, Section 609 of the Clean Air Act. Section 609 deals with the various certifications needed by technicians and the equipment they use. This "loophole" simply states that anyone providing A/C service for free does not have to meet the certification requirements set forth in section 609. This means that DIYers do not have to be certified technicians, and do not have to use approved equipment for refrigerant extraction. DIYers must use extraction equipment, but it can be a home-built system. Specifically, this clause does not apply to alternative refrigerants. It is illegal to use anything except approved refrigerants as a replacement for R-12. Please note that the EPA only regulates replacements for R-12. There are no restrictions on what may be introduced into an R-134a system, or what may be introduced into a system that has been converted to R-134a. The ban on venting refrigerants with a non-zero ODP still stands and applies to everyone. Starting in November 1995, no replacement for class I or class II refrigerants can be vented. This will include hydrocarbon based replacements if they ever achieve permanent approval. What if these HC based replacements are vented from a grill? It's unclear what the penalties will be for a person whose torch fails to light on the first spark. The ban on non-approved alternatives still stands, and applies to everyone. Only alternatives listed by the EPAs SNAP (significant new alternatives program) may be used in cooling systems. This section used to maintain a list of available alternatives and their status, but there are too many to keep up with now. The EPA has a very nice HTML formatted document that shows all substitutes and their current status. Please see this WWW page at: http://www.epa.gov/ozone/title6/snap/macssubs.html The bottom line is that DIYers can continue to service their air conditioners with only minor additional headaches (other than the 800% increase in the cost of R-12, courtesy of the US government). First, you have to take the MACS test (or equivalent) to get the federal license to purchase refrigerants. Second, you must have recovery equipment. This does not have to be certified equipment. The only requirements are: "the equipment must not vent to the atmosphere, and it must be capable of pulling at least 104mm of vacuum." [Jeffrey Levy] All refrigerant must be recovered from the system returned for reclaiming. Recovered refrigerants must be stored in a DOT approved container, marked 4BW or 4BA. The cylinders used by propane grills and on campers meet this specification. ----------------------------------------------------------------------- 12) Numbers and addresses of the players ----------------------------------------------------------------------- EPA Ozone hotline: 1-800-296-1996 http://www.epa.gov MACS PO Box 97 East Greenville, PA, 18041 (800) 609-6227 (215) 679-2229 (215) 541-4635 (fax) OZ Technology 1 208 664-6196 Monroe Air Tech (R-406A) 1 800 424-3836 Socity of Automotive Engineers (SAE) 1 412 776-4841 Greenpeace ozone crisis page http://www.cyberstore.ca/greenpeace/ozone/ozonehome.html NTIS, National Technical Information Service US Dept of Commerce Springfield, VA 22161 (703) 487 4650 Cryo-Chem Intl. (makers of Cryo-Silane) 1-800-237-4001 Intermagnetics (FRIGC) 1 800 555 1442 ----------------------------------------------------------------------- 13) Where can I get more infomation about this stuff? ----------------------------------------------------------------------- Here are references for material about the information in this FAQ. I have not read/looked at all of these. I make to claims as to their factual validity. Trashing the Planet : How Science Can Help Us Deal With Acid Rain, Depletion of the Ozone, and Nuclear Waste (Among Other Things) by Dixie Lee Ray , Lou Guzzo Published by Harperperennial Library Publication date: May 1, 1992 The Holes in the Ozone Scare : The Scientific Evidence That the Sky Isn't Falling by Rogelio A. Maduro , Ralf Schauerhammer Published by Twenty First Century Science Publication date: July 1992 ISBN: 0962813400 "Atmospheric ozone" http://icair.iac.org.nz/ozone/ozone.html A brief description of how ozone depletion occurs. "US EPA Stratospheric Ozone Home Page" http://www.epa.gov/docs/ozone/ "Usenet FAQ on ozone depletion" http://www.cis.ohio-state.edu:80/text/faq/usenet/ozone- depletion/top.html This is a FAQ that exhaustively covers questions and answers on ozone depletion. It is also posted regularly to news.answers "Government Publications Online" http://thorplus.lib.purdue.edu:80/gpo/ Electronically searchable index of government publications. Searches may be performed on House and Senate bills, the Federal Register, US Code, etc. "Ozone crisis page" http://www.cyberstore.ca/greenpeace/ozone/ozonehome.html A WWW page sponsored by Greenpeace about ozone depletion. ----------------------------------------------------------------------- 14) How can I make my own recovery equipment? ----------------------------------------------------------------------- Some easy ways to recover refrigerant are to take a recovery cylinder (or even a propane BBQ grill tank - it is DOT legal) and pull a vacuum on it just before the first use. A "50lb" recovery cyl is the same size as the 20lb propane BBQ grill tank. For these purposes, a 30lb recovery cylinder would work better (dont use a DOT39 "throw away" refrigerant cylinder). Get a Rubbermaid 5 gallon water cooler, and stick the 30lb cylinder in it, and add dry ice around the edges. This cools the cylinder so both R-12 and R-22 can be removed, and it will draw a vacuum on the system if left on long enough. If you can get it, liquid nitrogen works nicely also (-312F). Both dry ice and liquid nitrogen are very cold and can cause frostbite burns. Be careful. Precooling a cylinder in a freezer is usually not sufficient, it has to be colder than -21F to extract a charge from an R-12 system down to 0 PSIG. THe cylinder will warm up as the charge is removed. Wrapping a recovery cylinder with slightly flattened 3/8" copper tubing (on the outside), slowly venting liquid CO2 through the tubing would also be cold enough. Be very careful not to "overfill" the cylinder, use scales and don't exceed 70% of the "water capacity" (marked as WC), typically a BBQ grill tank will be WC 47.7, subtract out the tare weight (listed as TW), typically 12-13 lbs on a BBQ grill tank. JC Whitney sells propane level gauges which are temp strips which stick on the side of the tank, pour hot water on it, and the liquid level becomes visible. If the cylinder is overfilled, thermal expansion may result in 100% liquid full, when the cylinder warms up, causing the safety (popoff) to vent or the cylinder to explode. --ghg You can also build a recovery system out of an old fridge or electric A/C compressor. I removed the compressor from a 4 ft^3 (dorm style) refrigerator. The fridge was given to me as it no longer cooled. The compressor relay was bad, but the compressor itself was perfectly good. $10 worth of brass fittings and some teflon tape from the hardware store enabled me to connect a line from the gague set to the compressor intake. Running this compressor for approximately 30 mins drew over 30” of vacuum. Another set of fittings allows the compression side to be connected to a BBQ grill tank, thus resulting in a DIY evacuation system that is perfectly legal for DIY (unpaid) use. Pull a vacuum on the BBQ tank first. Note that the fridge compressor got very hot during use, hot enough to burn skin. I suspect it’s not designed to run for half an hour at a time. Next time I will place a fan blowing on it. A compressor from a house or window A/C unit would be a better choice as a vacuum pump, but the price was right for this one. --author ----------------------------------------------------------------------- 15) What is that white vapor coming out of the vent? ----------------------------------------------------------------------- Water vapor. You can see this any time the relative humidity is high outside and the A/C is not on "recirculate". It's not freon, or plutonium, or anything else. ----------------------------------------------------------------------- 16) What is the two step upgrade ----------------------------------------------------------------------- Here in Texas, that’s what we call a waltz... Ba dum bump. All hilarity aside, section 612 of the Clean Air Act gives the EPA a mandate for regulating Class I and II refrigerants, and replacements for them. The EPA does not regulate other refrigerants, or replacements for non-Class I or II refrigerants. In other words, the ban on HC based or other refrigerants is only in the context of using them to replace R-12. While it is illegal to replace R-12 with HC-12a (for example), it is not illegal to replace R-134a with HC-12a. A two step upgrade can be done to convert an existing R-12 system to the refrigerant of your choice. First convert the system from R-12 to R-134a, or another EPA approved non-class I or II substitute for R-12. Since the EPA doesn’t regulate your substitute, you can leave it in there or convert to any other refrigerant of your choice. You are free from all the other EPA regulations, such as the type of fitting, etc. It is left as an exercise to collapse this process to the minimal number or steps required to achieve the final objective, using a non-EPA approved R-12 substitute. The EPA has stated that they will vigorously prosecute anyone they suspect of performing a "sham switch". So try the replacement for a while, and if it doesn’t perform to your satisfaction feel free to replace it. ----------------------------------------------------------------------- 17) How could I make an HC based replacement if I wanted to? ----------------------------------------------------------------------- So you’ve done the first step of the two step upgrade, at least in theory, and now you are ready to upgrade to an HC based refrigerant for better performance. But you don’t want to send a lot of money to OZ technology, or you can’t find them. This section is for you. It describes how you can make your own refrigerant from commonly available hydrocarbons. The procedures described in this section were taken from rec.auto.tech archives, dating from June 1991 to the present. Most of the text can be attributed to either George Goble or John DeArmond. ************************************************************************ Disclaimer Some of the procedures described in this section may not be legal. Refilling some types of pressurized containers is illegal, as is replacing R-12 directly with a non EPA approved substitute. Several states have banned flammable refrigerants outright. The current list is: Arkansas, Conn., Idaho, Indiana, Kansas, Louisiana, Maryland, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington , DC. Check with your state to see what the exact restrictions are, if any. Hydrocarbons weight much less than CFCs, consequently much less mass is required to achieve the same pressures. Always charge using gauges to prevent overfilling. Check the pressure and temperature of your blend if you pre-mix and store. The pressure should be the same as R-12 at the same temperatures. Adding propane will increase the pressure at a given temperature, adding iso-butane will reduce it. ************************************************************************ The most commonly asked about hydrocarbon mix is 21% isobutane, 79% propane, by weight. Note that is isobutane, not butane or n-butane. This mix has the same temperatures and pressures as R-12, but performs better in your A/C system, partially due to being a blend. Hydrocarbons weigh less than CFCs, so you will need about half the weight of hydrocarbons to achieve the same performance. The paragraphs below describe how to charge this mix directly into your A/C system from the can, and how to pre-mix it in a large container for future use. Be sure to charge with gauges so you can stop at the appropriate pressure. Do not add the same weight as you would if it were R-12. Side tappers are available from JC Whitney and other places. A side tapper is a device that taps a can by piercing the side of the can, rather than the top. It will work on the small cans of refrigerants as well as cans containing other substances, whereas the standard A/C tapper will only work on refrigerant cans. In a ruling from the summer of 1995, the EPA ruled that it is illegal to use side tappers on cans of approved refrigerants. Use them on R-12, or on your custom blend, but it’s illegal to use them on R-134a or any other approved R-12 substitute. You’re supposed to use the fitting on top of the can. HOW TO GET IT ------------- Isobutane is available as the fuel used in Gaz brand camping stoves. Read the label to make sure you are getting isobutane and not n-butane. isobutane is generally used in stoves designed for low temperature use. Gaz sells both plus a propane/butane mix so read the label. Propane is conveniently available in propane torch cylinders. The odorant does not harm its use as a refrigerant. Don't use gas grill propane. This stuff is generally fairly wet. HOW TO PRE-MIX IT ----------------- You’ll need two old torch bodies fitted with refrigeration flare fittings, an empty propane torch cylinder, a side tapper, and some standard refrigeration service hose. An empty propane torch cylinder makes a very good mixing container, particularly the large fat ones. An old torch valve fitted with a refrigeration flare fitting lets you use it with A/C equipment. The procedure is simple and requires only a scales of some sort. A postage scale will work fine. Evacuate the propane cylinder if you have a vacuum pump. Then using a side tapper for blow-off cans (the type that punches a hole in the side of the can), introduce the correct weight of isobutane from the Gaz cylinder. Then top the cylinder off with the required weight of propane from another propane torch cylinder. Warming the donor cylinder will drive the process. A second torch body fitted with a refrigeration flare will let you hook the two cylinders together with a refrigeration service hose. Be sure not to overfill the recipient cylinder. Check this by slightly lifting the safety valve with the cylinder sitting upright. If liquid comes out (white mist, real cold), bleed the cylinder until the liquid is below the bottom of the safety valve. Needless to say, do all this outside. Before using the mix, double check the accuracy of the blend by comparing the vapor pressure in the cylinder to its temperature. This is easily done using refrigeration gauges. The vapor pressure should agree with that of R-12 +- 10 psi or so. When using your mix, charge with the bottle upside down, ie liquid into the system. Otherwise the propane will charge first due to it’s higher pressure. Charging as a liquid ensures that both the propane and iso-butane charge according to their proportions. Be careful to charge slowly, however, because if the liquid gets back to the compressor it can destroy it. When you modify a torch body, you'll need to find and drill out all restrictions that limit the propane flow to the torch. Typically there is a restriction and/or a check valve in the barb that taps the cylinder and another one downstream of the control valve. BTW, propane torch cylinders make convenient replacements for blow-off cans. They are much more gas-tight than the typical disposable freon cylinder so transfering valuable R-12, GHG-12 or whatnot makes real good sense. And they are more reliable. Instant sickness is dropping a 30 lb can of freon onto something that punctures it. :-( Be sure to label the cylinder contents. It is illegal to refill and transport disposable containers. BBQ grill containers are legal to refill, but are much less convenient. Be sure whatever container you use is clean initially. HOW TO CHARGE DIRECTLY INTO THE A/C SYSTEM ------------------------------------------ Go get a 6oz can of "isobutane" camping fuel. Charge that into the evacuated system first. Next follow up with 16 oz of propane (you will have to crock up a fitting to mate with a 16 oz torch tank). That should be close to correct blend and amount of charge to run a typical car A/C. It will be slightly lower in capacity then R-12. This mix will be 27% isobutane, 73% and will cause lower pressures than R-12, but should be close enough to work. The best mixture is 21% isobutane, 79% propane, so adding less isobutane and more propane will help. When it is time to recharge again, vent the remaining charge, and start over with a new fresh charge as the isobutane and propane will leak at different rates. HOW TO CLEAN BBQ PROPANE TANKS ------------------------------ You can clean the tanks by removing the valve, inverting them and blowing them out with 1,1,1-trichloroethane with an automotive power sprayer (like used for degreasing engines and about 200 PSIG air pressure. Next, install the valves, and pump them down to 400 microns of vacuum (an hour or so), and fill them with dry nitrogen for storage. On a propane tank, DO NOT USE WATER. K-Mart "brake cleaner" is 111- trichloroethane/perchlorethylene which would work fine. AN easier way, may be to just get it filled with propane, and invert the tank (in some field away from fire, sparks, (unless you want to participate in rec.pyrotechnics)), and open the valve all the way, and shake the tank. This should blow the shit/crud out. 5 or 6 seconds should get most of it. ----------------------------------------------------------------------- Appendix A -- People ----------------------------------------------------------------------- Thanks to the following people for providing useful information: Jeffrey Levy levy.jeffrey@epamail.epa.gov Christine Dibble dibble.christine@epamail.epa.gov George Goble ghg@ecn.purdue.edu John DeArmond Rob Lockhart Mike Wempe Greenpeace
So you're building a garage...
Things you'll want
- Compressor
- Parts washer
- Pressure washer
Wiring stuff...
- Lights -- the more the better. Have at least one that is switched inside the house if you have a detached garage.
- Phone -- with a pen/pencil permanently attached nearby.
- Power -- You'll need 220V for the compressor and for a welder you will probably want 220V 50Amps or a stove plug. And you will want to have both on at the same time. Put a 220V outlet near the car door so you can weld things in driveway.
- Install a circuit breaker box in garage. (It's easier to get to when you trip a breaker).
- Put your 120V outlets on separate circuit from lights. (So you aren't in darkness when you trip a breaker). Spread them around so you don't need long extension cords.
- consider running a large conduit between the house and the garage to permit running phone lines, TV cable, switched wires, alarm systems, air lines, etc. at a later date.
- Install an alarm system to protect your toys.
Compressor hints
- Make sure it's big enough. Look at the SCFM rating of the tools you want to use, and make sure your compressor is capable of running them.
- Locate your compressor outside your shop and put a small roof over it, but do allow lots of ventilation around it. You'll be glad to get the heat and noise out of the shop!
- Use 3/8 pipe throughout. PVC is available up to 300 PSI, but if it does burst it turns into shrapnel.
- Install "horizontal" runs of air line (in walls or attic) with a slope towards the compressor (you want to drain water away from the outlets). Make sure that the pipe is sloped as constantly as possible (i.e. no 'relative' low points which will hold water). Slope should be 1" per 4' of horizontal run.
- Connect the compressor via flexible, non-heat conducting pipe to a water trap/filter. My filter sits in a bucket which can be filled with ice water to help condense out moisture.
- Use an automatic water drain on the tank (spurts on every pressure cycle); also incorporate a manual drain for those times when you need to manual drain it!
- Use a decoupler hose (reinforced hose coupling) between your compressor and where it connects into the shop wall; this will also reduce vibration noises into your shop walls.
- For the drops from the attic to the shop, use galvanized pipe (it will help the moisture to condense out of the air).
- Place drops at each likely point you will need air; as a minimum one on each side of your shop (if not each wall), AND one at your beadblasting cabinet. I would also suggest a drop at the front of your shop for airing up tires of cars in the driveway, etc.
- Each drop should consist of a downpipe and a 'T' connection. From the 'T' come 6"-1' horizontally to your outlet. Place a 2-3' length down from the 'T' with a drain valve for collecting water. (Use the 'quick' handles for the drain valve instead of the 'water faucet' handles).
- Each outlet should be planned for what you want to do with it. All outlets should have a water separater/dryer and regulator and a female quick coupler.
- Plan for specific outlets for running air tools and other outlets for painting, sandblasting, beadblasting, etc. Use an automatic oiler for those outlets planned to run air tools. Do not use an oiler on your clean air outlets... (:^)
- You should also think about whether you should use 1/4" or 3/8" couplers; most air tools will work great with 1/4" outlets and they are cheaper and more convenient. But you should use 3/8" couplers for the sand blaster, and bead blaster to get more air with less drop.
Ventilation
- Be able to blow air into the garage from a known point (fan in window). This way you can filter it, and put positive pressure on the garage. This is a bad idea for an attached garage, though.
- Be able to suck air from the garage from a known point. Again, a fan in the window.
- Make exhaust vents for car exhaust pipes (use dryer ducts).
- Lots of windows for light and ventilation. Also lots of fans.
- Install a furnace or heater. Either electric or outside the garage to prevent fires.
Construction
- Go to the lumberyard and buy one or several 4'x8' sheets of pegboard. Nail 'em to the studs for hanging tools, extension cords, or whatever. Pegboard comes with 2 size holes, 1/4" for big stuff and 3/16" for little stuff. The pegs are sized correspondingly. The 1/4" pegs fit the holes much tighter IMHO.
- Consider using two layers of concrete blocks and building an 8 ft. wall on the blocks to get a 10 ft high garage. This prevents rotting of the walls, allows washing garage with hose, and prevents water from flooding in.
- On a double car garage, get a single large door. This will allow lots of room on each side with the project parked in the middle.
- Install an extra car door in the back of the garage for access to the backyard, and ventilation. Put it directly across from the main door so you can drive straight through.
- One door extra high. If you have a conversion van, it will not fit in many normal garage doors. Go for an 8 ft. or 10 ft door height on at least one door.
- If the floor is brand new, consider painting it. Look in the Granger catalog for paints. There are paints in there that can survive a mild oil fire!!!. Cleanup is easy and this will allow you to move heavy things just by sliding them on the floor. It the concrete is dirty or old, you may be able to clean it. But if you don't do a perfect job the paint won't stick and you end up with peeling paint - a worse mess IMHO.
- Cabinets! It's very cool to look into a garage and not see anything lying around. Old kitchen cabinets are great to hold books, tools and everything. Also keeps them away from prying hands. Number the doors and drawers so you can tell someone else exactly where a tool is while you are lying under the car.
- Paint the inside white.
- Have a high ceiling. This will allow for lofts and a lift.
- Include a loft area for storage. Be sure to use real stairs to get to the loft (the attic type is too light for carrying transmissions).
- Make it deeper than you would normally expect. Most compacts are 15' long and need 20' to work around, a truck like a Suburban or Crew Cab will be closer to 24' long with 30' needed to work around it.
- Fiberglass car doors are lighter and allow light through.
- Steel car doors are better for security.
- Install a drain in the floor.
- Slope floor towards the car door.
- Have a level section of floor for alignments.
- Install water and a large wash-up sink in the garage. Your significant other will be happier.
- At least one large, heavy workbench. A "detailing station" with lots of light and a clean (formica?) surface. A "clean room" away from messy equipment for assembling engines, etc.
- Install a lift or a pit.
- Have one heavy beam to attach your chain hoist to. Put a trolley on it so you can move the engine to the engine stand without having to move the car.
- Install tie down bolts in the floor. That way you can winch a car into the garage or pull parts. Use long, heavy bolts and a plate embedded into the concrete while pouring if possible.
- Don't forget the parts washer.
Buying a new car
Dealers are only interested in the amount of profit they will make on a sale. Every vehicle has a Manufacturer's Suggested Retail Price (MSRP, aka sticker price, moroney, etc.) and an invoice price (the theoretical price the dealer pays for the vehicle). The difference between the two is the "markup or profit margin." If they sell it less than the MSRP, they have discounted the price. Dealers generally negotiate a deal based on the amount "over invoice," i.e., if they want to make $500 profit, they sell it for $500 over invoice, etc. The Edmund's homepage Tom referred to should tell you what the MSRP and invoice are of most any vehicle, based on the last time I viewed it (though it isn't always up to date). You can also buy "Edmund's" new and used car price guides at many book/magazine stores, that have the up to date prices (Edmund's would rather sell you the information as opposed to give you the information free on the Internet).
To complicate the matter, you will also hear about an amount referred to as "holdback." Holdback is an amount referenced on the actual invoice. This is generally about 3%. Manufacturers give the dealers a check quarterly for this amount. This amount is what the dealers use to cover their overhead (and maybe a little profit, depending on the overhead of the dealer, though they generally won't even discuss the holdback when negotiating a price for a car).
The last few cars I've bought for myself and friends I've bought over the phone. If you do the research and know what you want to buy, which options you want, and have determined what the invoice should be, you are ready to start. Many dealers in larger metropolitan areas have advertisements (in the used car section oddly enough) for fleet sales. When you call those numbers, tell them what you want to buy and ask them if they have a vehicle like that and how much over invoice they will sell it for. If they tell me they want $500 over invoice (about the going rate for a vehicle anybody would want), I generally say something like "I can buy it in the Bay Area for $300 over, can you meet that?" After you've done this with a few dealers (generally the ones you've heard of that give the best deals), you can be fairly sure that you're getting about the best price possible. If you buy a current model year vehicle that's selling at a normal pace for less than $200 over invoice, you got a good deal! And make them show you the real invoice! And don't negotiate based on your monthly payment (email me direct, I'll tell you why)!
Of course if the manufacturer is giving the dealer an incentive to move cars, the dealer can sell the vehicle for less than invoice. This often happens at the last of a model year, or when a particular model isn't moving well. Edmund's seems to have good information on which manufacturer is giving what kind of incentives or rebates. Of course if a manufacturer is giving a $1000 rebate to the dealer, you'd want to negotiate from a price that's $1000 less than the usual invoice price. Or if it's the end of a model year and the new model year is already being sold, or if it's a vehicle that's been put into "demo" (short for demonstrator) service, you can deduct another 5% for either of those (approximately). The manufacturer gives the dealer rebates for those. Oddly enough, if you start discussing these issues with the dealer, especially over the phone, it's amazing what I've had them volunteer, e.g., "The manufacturer's giving us an X% rebate right now to reduce inventory, or get rid of last year's model."
And then there's the profit they make on financing, extended warranties, alarm systems, stereos, rustproofing, etc. Because the above information (actual dealer cost) is so easy to get, and today's buyers are so knowledgeable of dealer cost, dealers generally make more profit on these other items than the new car itself. You're generally better off to arrange your financing elsewhere (unless the dealer can offer a lower rate than your credit union), and negotiate the Hell out of the amount they want for extended warranties, or any addons. For example, it's not uncommon for a dealer to want $800 for an extended warranty, and if you negotiate you may get it for $300.
And then there's what you're going to get for your trade in. Four words...don't trade it in...unless it's a piece of crap and you don't want some private buyer coming back to tell you. The dealer will only give you wholesale price for a trade in, because they have to resell it and make a profit. The used car lot has to make a profit on what they sell too. But remember, that wholesale amount is negotiable too!
Another thing to remember, if a dealer is selling you a car without air conditioning, and you want a/c, they make the profit on the car they sell, the parts department makes it's profit on the air conditioning kit they sell to the service department, and the service department makes it's profit on the installation. That's 3 markups. If you buy the car that has factory air, you only pay the profit on the car (and you don't give the service department the opportunity to screw up the installation)! Sames goes for all other add on accessories.
Based on the current Edmund's figures, a 1996 Coupe costs the dealer $32,432 (without any options). My guess is that a dealer's cost on a leftover 1995 Coupe (without any options) is around $28,000. Trust me, I've seen few examples where the dealer didn't make a profit. So, your job, if you so choose, is to determine how much the car is costing them and how much profit they're making.
Hope this was of some value. And believe it or not, this was the condensed version...I didn't even talk about buying used cars. Actually, I've been sitting on the other side of the table (purchasing/contracting) for the last 20 years. I spend your tax dollars. I hope this doesn't get me as much wrath as being an attorney did a couple of other people.
Jim mailto:flattop@calweb.com
