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.
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. . . .
Notice: This product has NOT been certified for legal use in CA and other states adopting CA emissions standards under Section 177 of the Federal Clean Air Act of 1970. Please check with laws in your area to make sure that your use of this product is compliant with current regulations in your jurisdiction.