What's an Underdrive Pulley?
Underdrive Is the Slowing of the Rate of Rotation in a System, Achieved by Either Making the Crank or Main Pulley Smaller or Making the Accessory Pulley Larger...
Underdrive is the slowing of the rate of rotation in a system, achieved by either making the crank or main pulley smaller or making the accessory pulley larger than the original diameter pulleys.
Do underdrive pulleys add horsepower?
Underdrive pulleys will yield a small increase in horsepower anywhere from 8 to 15 hp. This is accomplished by reducing the amount of power needed to drive the engine accessories that eat up precious horsepower.
Is an underdrive pulley worth it?
For many owners, there is no downside to the installation of underdrive pulleys. In most situations, owners are swapping pulleys and that is it. They receive improved responsiveness from the vehicle, along with a little extra power to enjoy.