Actually these have nothing to do with supercharged or non-supercharged applications.
Lightweight pulleys work the same way as a lightweight flywheel or lighter wheels and tires, lighter brakes...Any time you can free up some rotating mass you are freeing up horsepower. By reducing the weight of the pulleys you are reducing the energy or horsepower required to spin them. It makes your engine much more efficient.
If you plan on getting a supercharger sometime down the line we do not recommend getting an underdrive pulley. An underdrive pulley will underdrive everything that is powered by your engine...Basically meaning your supercharger will be underdriven. Lightweight pullies are great for superchargers, but we don't recommend installing underdrive pullies for supercharged vehicles.
Turbo vehicle's will benefit from either light weight or underdrive pullies.
|