ALTA Supercharger Pulley – 15% Reduction – MINI Cooper S / JCW (SKU: AMP-ENG-200V2)

Unlock smoother, safer power gains with the ALTA 15% Supercharger Pulley, precision-engineered for supercharged MINI Cooper S and JCW models. Crafted from lightweight 6061-T6 aluminum, this pulley reduces rotational mass, improving throttle response and adding up to 20 WHP.

The Version 2.0 design features a stainless steel clamp-on coupler, oversized belt retainers, and cross-drilled grooves for superior belt grip. Unlike other press-fit pulleys, ALTA's clamp-on hub securely attaches even to worn shafts—up to .020" wear tolerance—making it an ideal solution for damaged or previously modified superchargers.

Balanced for performance at up to 16,000 RPM, this pulley offers high-speed reliability and long-term durability. ALTA pioneered this clamp-on method, and it remains the gold standard for MINI pulley upgrades.

Key Features:

• 15% Reduction Drive Ratio – Increases supercharger speed for ~20 WHP gain

• 6061-T6 Billet Aluminum Body – Lightweight, anodized, and naturally balanced

• Stainless Steel Clamp-On Coupler – Secure fit on worn or damaged shafts

• Cross-Drilled Grooves – Enhances belt grip and reduces slippage

• Oversized Belt Retainers – Prevents belt derailment under boost

• Balanced to 0.1g @ 16,000 RPM – Better than stock-level balance

• Version 2.0 Design – Improved construction and shaft engagement

• Install Aperture – Allows visual confirmation of proper fitment

• Compatible with ALTA Pulley Removal Tool (AMP-ENG-208)
  (Not compatible with JCW or GP pulley removal)

Vehicle Fitment:

• 2002–2006 MINI Cooper S Hardtop (R53)

• 2004–2008 MINI Cooper S Cabrio (R52)

• 2002–2006 MINI Cooper S JCW / GP
  Pulley fits, but ALTA pulley puller will not remove OEM JCW/GP pulley.

What’s Included:

• (1) ALTA Supercharger Pulley Hub – 303 Stainless Steel

• (1) ALTA Supercharger Pulley Body – Black Anodized 6061-T6

• (5) Grade 12.9 Bolts & (5) Grade 10.9 Hi-Collar Lock Washers

• (1) Allen Wrench

• Instructions

• ALTA Warranty Info

• ALTA Stickers