Dinan 13% Underdrive Crankshaft Pulley Kit for BMW E60 M5 & E63/E64 M6 (S85 V10, 2006-2010) - Lightweight Billet Aluminium Power/Accessory Drive Crank Pulley Upgrade with Belts

Unlock effortless power on your BMW S85 V10

Free up real-world performance with this precision CNC machined lightweight crank pulley upgrade for the E60 M5 and E63 E64 M6. By underdriving the accessory system by 13 percent, it reduces parasitic losses, helping the engine rev more freely and deliver a noticeable bump in acceleration and throttle response. Expect gains of around 6 bhp and 4 lb-ft torque (about 5 Nm), with a sharper, more eager feel across the rev range.

Why enthusiasts choose this pulley

• 13 percent accessory underdrive for reduced drag and improved response
• Retains the factory harmonic balancer for OE-level smoothness and reliability
• Lightweight billet aluminium construction for lower rotational mass
• Direct bolt-on fit with shorter belts and all mounting hardware included
• No software required and fully compatible with stock or tuned S85 engines
• Backed by a 4 year or 50,000 mile warranty from the manufacturer

We run this upgrade on our own demonstrators and have installed it on numerous customer cars. Owners consistently report a crisper pedal, faster rev pick-up and a more responsive V10 without compromising refinement. It is a brilliant street and track day friendly modification that complements other breathing and exhaust upgrades.

Built for reliability

The design keeps the original crank damper in place, maintaining crucial vibration control to protect the crankshaft. The result is a durable, performance-focused pulley solution that prioritises longevity as well as speed.

What you receive

• Lightweight billet aluminium crank pulley
• Shorter accessory belts matched to the underdrive ratio
• All required mounting hardware
• Fitting instructions from the manufacturer

Compatibility

• BMW E60 M5 Sedan 2006 to 2010
• BMW E63 M6 Coupe 2006 to 2010
• BMW E64 M6 Convertible 2007 to 2010
• Engine: S85 5.0 V10

Ideal search terms

BMW M5 crank pulley upgrade, M6 S85 lightweight pulley kit, V10 underdrive pulley, accessory drive pulley for E60 M5, E63 M6 performance pulley, billet aluminium crank pulley, power pulley kit, reduced parasitic drag, throttle response upgrade, bolt-on pulley conversion, harmonic damper retained, dyno proven power increase.

Professional installation

Want it fitted perfectly first time? Book installation with MJ Modifications in Warwickshire. Request a quote at info@mjmodifications.co.uk.

Add this to your basket today for a simple, high value performance gain that lets your S85 V10 breathe easier and pull harder.