When every last bit of reliable output counts on the track, the VAC Motorsports’ Underdrive Crank Pulley for BMW S14 engines will ensure lowest possible parasitic loss.

This pulley is designed featuring a step on the back side to easily accept their Crank Trigger Rings for your standalone ECU install, whatever manufacturer you are using.

Tech Notes:

– VAC recommend this pulley not be used on any street car, race use only.

– This pulley can be used in conjunction with VAC’s Underdrive Power Pulley Set, but only on very high revolution S14s

Also known as VAC part number VAC-11-CP-U-S14.