Turning the supercharger at a faster rpm produces more boost and more real horsepower! Pulleys are made from AISI/ASE 1144 Stressproof round bar (medium carbon steel) for great machinability and durability. Measurable boost is dependant on many factors, including but not limited to; modifications such as air intake, exhaust, cam (with rockers, pushrods and springs), temperature, barometric pressure and altitude etc. We suggest at the minimum to install a custom air intake and a boost gage when running any overdrive supercharger pulley. The ?2.3" runs 10 to 12 PSI. RPM levels--?2.3" = 14348 sc rpm @ 5500 engine rpm or 14000 @ 5367.
