Aftermarket Audi S4 camshafts are one of the best ways to make power, since they essentially control your engine's combustion charge of air and fuel by opening and closing the intake and exhaust valves at a set time. By giving your Audi S4 engine a more potent mixture, power can be increased through a specific RPM range determined by the camshaft's specifications.

Camshafts can be described differently by various manufacturers, so be sure to compare all of the info in Audi S4 camshaft descriptions to make sure that you are getting exactly what you are looking for. In general, longer duration equals more power, but that sometimes comes at the expense of low-end drivability. Choose a camshaft based on your driving needs, as an extremely high lift/duration Audi S4 camshaft would probably not do well for a street-driven vehicle. Remember that camshafts are a compromise, as they work best at specific RPMs, so pick the best compromise for your needs.

Q: What do camshafts do? Why buy camshafts?
A: Air travels through your intake manifold into your intake valves and exhaust valves. By upgrading to more aggressive camshafts on both the intake and exhaust side, it will create greater duration and lift. This means the intake and exhaust valves can remain open longer, which allows for more air to move through the cylinder head efficiently. If you're looking to get more horsepower out of your car, aftermarket camshafts are a great option.

Q: Are camshafts sold individually?
A: Camshafts are sold individually unless otherwise noted in the product description. Single overhead cams (SOHC) utilize one camshaft while dual overhead cam (DOHC) motors utilize two.

Q: How do you install camshafts?
A: Installation should be left to the pros on this one since timing will be involved. If you plan on doing it yourself removal of the upper timing belt cover will need to be done to reveal the cam gears. The valve cover along with the camshafts will need to be removed. Once this is done replace your factory camshafts the aftermarket camshafts and reinstall your cam gears. Make sure when you remove and reinstall the camshafts and cam gears they are at top dead center (TDC). Replace everything as you removed them and re-time your vehicle.