Fuel Injector Size Calculator

In order for your engine to run it takes air, fuel, and spark. The fuel injector supplies the fuel and is controlled by vehicle's computer. To increase your horsepower you have to increase the air and fuel supply to your engine.

The calculator bellow will help you figure out what size of injector will give you the horsepower you are after!

Injector Flow Rate Calculator

  Typically the Brake Specific Fuel Consumption (BSFC) for naturally aspirated engines
  ranges from .4 to .5, for turbocharged / supercharged engines this number is slightly
  higher .5 to .6 . You can either select a preset option or choose Custom.

  Please select your BSFC from the following options:

                                          Naturally Aspirated :
                                          Turbo/Super-Charged :
                                          Custom :

  Please enter your target variables:

  Enter desired horsepower :
  Enter number of injectors :
  Enter desired Duty Cycle :

  ex. 350
  ex. 8
  ex. .80


  Tire Size Calculator

When you have made the decision to upgrade your set of wheels, tires come to mind. There is a wide range of tires available that come in different sizes and composed of various materials. We will eliminate one of the head aches that comes with choosing tires : Size!

Example: 195/55/16

The section width is the width of the tire from outside edge facing the street to the inside edge facing the vehicle. Section width in this case would be 195. It is measured in millimeters. The aspect ratio is the height from the edge of the rim to the edge of tire that touches the pavement. Aspect ratio in this example is 55. Aspect ratio expresses the height to width ratio as a percent. The smaller the number, the lower the profile. A 55 aspect ratio means the tire's cross sectional height is 55% of it's width. The wheel diameter is the distance between one point of the rim's edge to the opposite side of the rim's edge. The wheel diameter is the last number, 16 in this example, measured in inches.

The rule of thumb here is you can usually go +/- 2 sizes from the factory wheel diameter without any modifications. So with the tire size above, you could safely put 18-inch rims on your vehicle without fear of rubbing.

The calculator below will help you figure out what size of tires will be as close to the factory size as possible!

Tire Size Calculator

  Please enter the factory tire size which could be found on the side of your tires:

  Enter section width :
  Enter aspect ratio :
  Enter wheel diameter :
  Enter desired wheel diameter :

  ex. 195
  ex. 55
  ex. 16
  ex. 18


  Backspace-Offset Calculator

Know how to measure or have been able to locate your rim's backspace, yet the new set of rims you like is listed with offset? Not a problem!

To convert from inches to millimeters simply multiply your number in inches by 25.4.
To convert from millimeters to inches simply divide your number in millimeters by 25.4.

The calculator bellow will help you figure out what backspace matches which offset!

Backspace to Offset Calculator

  Backspacing is measured in inches.
  Offset is measured in millimeters.
  Wheel Diameter is measured in inches.

  Please enter either an Offset or Backspacing and the Wheel Width:

               Backspace to Offset :
   Offset to Backspace :

Rim Diameter:


  Gear Ratio/MPH Calculator

Select one of the presets below to automatically fill in the boxes. You can also click on Clear Top to clear them all out and use your own values, or just edit each box to your liking.

Gear Ratio/MPH Calculator

Tire Size
(e.g. 245/50-16)
/ -
Tire Diameter
(in inches)
Revolutions Per Mile
Axle Ratio
Redline (RPM)
First Gear
Second Gear
Third Gear
Fourth Gear
Fifth Gear
Sixth Gear