Lightweight aluminum supercharger pulley that reduces rotational inertia so the Eaton supercharger spools and builds boost faster. Cross-drilled belt grooves and oversized retainers improve belt grip and stop belt walk under load. The 17% reduction adds roughly 1.5 psi more boost at redline for about 20+ wheel-hp on an otherwise stock MINI Cooper S.

Fitment: MINI Cooper S (R52/R53) and John Cooper Works GP/MC40 (R53), W11 1.6L supercharged engine. A matching belt is recommended when installing a reduction pulley.