Intended for ultra-high output applications, VFE's S/C Pulley Kit is designed to optimize rotational speeds when using larger superchargers pushing 12-18 psi. The units are carved from aerospace-spec aluminum stock and then triple-hard anodized before being rotationally balanced. VFA13-4884-E46 Full Pulley Kit-CS/WP/PS/Alt $1,250performance-pulley-e46-(1-of-1)