Dinan Underdrive Pulley Kit for BMW M3 E9X (E90 E92 E93) 05/2008+ - S65 V8 Performance Upgrade, 6061 Aluminium Black Anodised, Retains Factory Harmonic Damper

Dinan Reduced-Drive Crank Pulley for BMW M3 E9X S65 V8

Free up real, useable power on your S65 V8 with this Dinan reduced-drive crank pulley. By lowering the accessory load on the serpentine system it lets more of the engine’s output reach the tyres, delivering quicker revs, sharper throttle response and a livelier feel without sacrificing everyday refinement. Proven in high heat testing and road use, this is a must-have bolt-on for E9X owners who want extra performance without a tune.

Precision CNC machined from 6061-T6 billet alloy with a hard black anodised finish, the pulley is built for longevity and corrosion resistance. Crucially, it keeps the OEM vibration damper in place instead of altering it, preserving reliability and long-term engine health while still reducing accessory drive ratio for measurable gains.

Key benefits

• Releases power by lowering accessory load on alternator, coolant pump and air con compressor
• Noticeably faster rev pickup and improved mid-range urgency on the S65
• CNC 6061-T6 aluminium construction with durable black anodising
• Retains factory balancer for OEM-level smoothness and peace of mind
• Track-capable yet daily-friendly, validated in hot climate conditions
• Quality engineering from a trusted BMW tuning brand

Compatibility

For BMW M3 E9X with S65 V8 built after May 2008:

• E90 M3 Saloon 2008 to 2011
• E92 M3 Coupé 2008 to 2013
• E93 M3 Convertible 2008 to 2013

Not suitable for early pre-05/2008 production vehicles.

Why M3 owners choose this pulley

We run this upgrade on our own S65 cars and our customers consistently report smoother revs, crisper response and a more eager feel without compromising driveability. It is a simple, effective power-freeing mod that complements exhausts, intakes and software later on if you choose.

Installation

Professional fitting recommended. MJ Modifications offers in-house installation at our Warwickshire workshop. For a fitting quote email info@mjmodifications.co.uk.

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