Mazda RX8 Underdriven Race Pulley Kit

Fits series 1 RX8 / Renesis Engines (2003-2008)

Green Brothers have designed this kit to have the least amount of horsepower loss possible. Diameters and resulting pulley speeds are optimised for waterpump and alternator efficiency. Slowing down the waterpump significantly reduces impeller cavitation and parasitic drag. The narrower than stock4PK belt has less weight & frictional loss than the factory width belt. The net result is lower coolant temps, less power loss, and improved engine acceleration response

• Lightest weight kit available with a combined pulley weight of just 310grams
• CNC machined from 6061 T6 billet aluminium. Designed and manufactured in-house 
• 35um semi hard black anodised for surface toughness and longevity 
• Machined to tight tolerances eliminating runout and wobble (both of which rob engine power) 
• Supplied with OEM quality belt 

If you're trying to control coolant temps we recommend Green Brothers billet impeller waterpump be used in conjunction with this pulley kit 

Designed for racing. Will not work with A/C pulley