Dinan D560-0001 Underdrive Crankshaft Pulley Kit for BMW M5/M6

The Dinan D560-0001 Underdrive Crankshaft Pulley Kit is engineered to reduce parasitic drag on BMW M5 and M6 engines, freeing up horsepower for improved performance. This complete kit includes a precision-machined billet aluminum crankshaft pulley, mounting hardware, and shortened accessory belts for a complete bolt-on installation.

Key Features:

• 13% underdrive ratio reduces drag on all engine accessories including alternator, water pump, and power steering
• Lightweight billet aluminum construction reduces rotating mass for quicker engine response
• Black anodized finish with laser engraving for durability and professional appearance
• Includes all necessary mounting hardware and properly sized replacement belts
• Direct bolt-on installation with no permanent modifications required

By underdriving the accessory components, this pulley kit allows the engine to spin more freely while maintaining proper accessory function. The reduction in parasitic loss translates to measurable gains in both horsepower and throttle response, particularly noticeable in the upper RPM range where accessory drag becomes most significant.