With a stock engine, horsepower (HP) is typically lost in the requirement to drive accessory pulleys (water pump, power steering, alternator, A/C). This parasitic loss can often be reduced by under-driving certain engine pulleys. For a number of years, Evosport has been a recognized leader in developing under-drive pulley systems that safely reduce this parasitic power loss in high-end European vehicles, resulting in measurable HP gains. With its Power Pulley System for the new BMW V8 M3 producing a net gain of approximately 21 HP and 8 ft-lbs of torque on CA91 octane, Evosport has once again developed a superior product for performance-minded BMW M3 owners. Pulley System features: -Custom-designed and engineered crankshaft pulley manufactured by evosport; T-6061 billet aluminum, black anodized, laser-etched logo -Simple bolt-on design