The MMR Performance One-Piece Crank Hub Upgrade Kit is the definitive solution to one of the most notorious weaknesses in BMW’s S55 and N55 engines—the OEM three-piece crank hub’s tendency to slip under load. In the factory design, the friction plate can rotate independently, altering timing just enough to risk piston-to-valve contact and catastrophic engine damage. Whether on a completely stock car or a high-powered build, this upgrade replaces the compromised multi-piece unit with a single, precision-engineered billet EN36 crank hub that eliminates slip entirely. Heat-treated with a 0.75mm case hardening, this hub is built to withstand extreme stress, delivering race-proven durability and bulletproof reliability.
For drivers seeking absolute protection, the optional MMR Capture Plate offers the next level of security—machined from billet aluminum and bolting directly over the crank bolt head to physically prevent loosening due to vibration or harmonics. Together, the One-Piece Hub and Capture Plate form the most comprehensive and cost-effective solution available, ensuring flawless timing retention for street, track, or competition use. With unmatched engineering precision and premium materials, this kit delivers confidence and performance that no OEM setup can match.
Product Details:
- Precision-machined from billet EN36 with 0.75mm case hardening
- One-piece design eliminates friction plate slip found in OEM hub
- Heat-treated for maximum strength and long-term reliability
- Direct fit for BMW S55 and N55 engines
- Ideal for both stock and heavily tuned applications
- Optional billet aluminum Capture Plate for ultimate bolt security
- Designed for professional installation with proper crank bolt torque procedure
- Perfect for high-performance street cars and dedicated track builds
