Dyno Comparison -- Stock vs. Hypertech Underdrive Crank Pulley

Dyno graph of before and after underdrive crank pulley.

Here, the dyno shows a 0.7 horsepower and 5.1 ft/lbs torque difference between the stock crank pulley and a Hypertech Power Pulley. This produced an average gain of 4.4 horsepower and 5.8 ft/lbs torque. Remember, average numbers count too, as that is your area under the curve. Check out the Dynojet Race Routine between the stock vehicle, the K&N equipped car and the Power Pulley equipped car.
Note: All runs were performed with the car at approximately 180 degrees at the start of the run.


Again I could not feel a power increase in acceleration, but the engine is much more responsive in neutral and when blipping the throttle for downshifts. I makes the engine respond to throttle much quicker. Also, by turning the accessories slower, I am actually saving wear and tear on the alternator, a/c compressor, air pump and power steering pump. The power steering pump on the fourth generation cars is a reverse flow design that is very expensive and is also succeptable to overheating from sustained high RPM use. See my power steering cooler installation to see how to help remedy the problem.