Turner Motorsport BMW S85 V10 Underdrive Pulley Kit – Lightweight Accessory Drive/Power Pulleys for E60 M5 & E63/E64 M6, S85B50 Performance Pulley Set (Alternator, Water Pump, Power Steering)

Unlock easy, proven gains on your BMW V10

Free up real wheel horsepower on your BMW E60 M5 or E63 E64 M6 with this lightweight underdrive accessory pulley set for the S85B50 V10. Independent dyno testing has shown increases of 18 to 22 bhp and 17 to 21 lb ft on a standard car, without any software tune or other hardware.

Why enthusiasts choose this upgrade

This performance pulley upgrade reduces parasitic drag from the accessory drive so more of the engine’s output reaches the tyres. By optimising the drive ratio for the alternator, water pump and power steering, you gain sharper throttle response and stronger mid range pull while retaining everyday reliability.

• Genuine, repeatable power increase on stock S85 V10 engines
• CNC machined from high grade 6061 aluminium for strength and reduced rotating mass
• Hard anodised black finish for durability and resistance to heat and chemicals
• Track and road validated to maintain correct accessory function
• OEM like appearance with a motorsport focus on efficiency

What you will notice

• Faster revs and improved acceleration
• Smoother delivery through the rev range
• More responsive feel without compromising drivability

Vehicle compatibility

• BMW E60 M5 5.0 V10 S85
• BMW E63 M6 5.0 V10 S85
• BMW E64 M6 5.0 V10 S85

Built for long term performance

Constructed from premium aluminium and finished in a hard wearing anodised coating, this underdrive pulley kit is designed to withstand heat cycles and chemical exposure in demanding conditions. It delivers the efficiency gains of a lightweight accessory pulley set while looking right at home in the engine bay.

Trusted by owners and our workshop

We have installed this upgrade on multiple customer cars and the feedback is consistently positive. Drivers report a livelier top end and a noticeable improvement in real world pace. It is one of the most effective bolt on mods for the S85 platform if you want extra performance without a remap.

Ideal search terms and related uses

BMW M5 pulley upgrade, BMW M6 underdrive pulleys, S85 V10 accessory drive kit, lightweight pulleys for E60 M5, alternator and water pump pulley set, crank drive pulley upgrade, drive belt performance pulleys, reduce parasitic loss, horsepower increase without tune, UK BMW performance parts.

Professional fitting available

Installation is a straightforward bolt on for a specialist, and we recommend professional fitting for best results. Book with MJ Modifications in Warwickshire. Request a fitting quote at info@mjmodifications.co.uk.

Note: Figures quoted are from testing on standard cars and may vary depending on vehicle condition and supporting maintenance.