S55 Crank Hub Upgrade

Want to unlock the potential of your engine while ensuring reliability?

We’ll need to address a critical issue with the factory S55 crank hub.

It relies on a friction disk to mate the multi-piece component together, and as you increase the power output, you risk catastrophic failure by surpassing the friction limit: skipping engine timing and bending valves.

Our upgrade of choice is the RK Autowerks S55 Crank Hub as it utilizes billet 4130 Chromoly, is keyed, and uses four pins to securely connect to the crankshaft. We have had success through the years with this in plenty of our client cars, as well as, our own F80 M3 race build.

The RK Autowerks S55 Crank Hub is also utilized in our BMW S55 Motor Build Program with motors rated for over 1200whp.