We'll be honest... We never thought performance underdrive pulleys made a difference, UNTIL, we fit these on our own E92 M3. Paired with the rest of the bolt-ons, the pulleys completely transform the character of the S65. Free power!
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.
The DualDrive design replaces the Crank Accessory & Power Steering Pulleys, resulting in 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 accessory operation and come fully equipped with new belts.