Macht Schnell Performance Underdrive Pulleys - BMW E9X M3 / E60 M5 / E63 M6

Free additional power to your M3/M5/M6’s rear wheels without sacrificing or compromising your BMW’s reliability. Machined from 6061-T6 aerospace aluminum, Macht Schnell Performance Underdrive Pulleys are strong as well as lightweight to limit parasitic drag from the accessories within a moderate level for maximum performance on or off the track. After machining and engraving, pulleys are then T3 hard anodized for additional strength, anti-corrosion & wear resistance. Our DualDrive design replaces the Crank Accessory & Power Steering Pulleys, resulting in 18-20 HP and 16-20ft. lbs TQ gain for the M5/M6 and a 9-14 HP and 7-9ft. lbs TQ gain for the M3. Gains are due to a reduction in power required to turn accessories; an increase in accessories lifespan due to lower speed will also result. All factory harmonics/balancing are undisturbed. Macht Schnell Performance Underdrive Pulleys have no negative effect on the accessory operation and come fully equipped with new belts. Performance Underdrive Pulleys Features: - DualDrive design allows maximum performance, with minor affect on accessory speed - Proper cooling temperatures are retained at proper levels on or off the track - Maintains proper alternator speed, allowing sustained levels to sensitive control modules - Machined from 6061-T6 aerospace aluminum - T3 Hard-Anodized for maximum strength and corrosion/wear resistance - No affects on crankshaft dampening or harmonics - Simple bolt-on installation Models Supported 2008+ E9X M3 2006-2010 E60 M5 2006-2010 E63 M6 NOTE FOR E9X M3: If your power steering belt is double sided, please select 06/08+