Smaller S/C pulley spins faster.
Faster spin increases boost.
More Boost increases acceleration.
Safe for extended Use
CravenSpeed's supercharger pulleys are machined to a specific reduction of the original equipment on your MINI's supercharger. It is widely accepted that these sizes are safe amount of reduction on this particular supercharger. Smooth, form fitting teeth on your pulley take longer to machine but are worth the extra time. Our pulleys will neither eat nor throw your belt. You can be confident your belt will last long, and run quietly. We do recommend using a slightly smaller belt with these reduction pulleys, a NAPA 060539 or similar.
15 or 17?
If both sizes are safe for the supercharger which one should you choose? The supercharger is only creating boost under acceleration, on a normal or even a spirited drive this is only occasional. However, at the track or an autocross event acceleration is sustained and frequent. If you use your MINI for these types of events it is better to use the 15% reduction. This is because the 17% pulley causes the supercharger to heat more rapidly and the warm air begins to negate the positive effects of the extra PSI earlier in the band.
This pulley will work on all supercharged MINI models except the JCW which already has a similarly reduced size pulley on the supercharger. Although this two part pulley is self-centering to help ease installation you may still want to check our
for a CravenSpeed Authorized Installer near you. If you plan do on wrenching on your own, make sure you have a puller
designed to remove the MINI's press-fit OEM pulley. Our quick puller allows you to remove the OEM pulley without removing the tensioner.