In the BMW S55 engine, camshafts are connected to the crankshaft via a camshaft chain. This chain, in turn, is connected to a sprocket that’s mounted on the crank hub. In stock form, this sprocket is not fixed on the crank hub, putting tuned engines at considerable risk of failure. If the sprocket shifts out of alignment due to increased power, so does the engine’s timing.
The MSL Crank Hub offers a vast improvement in terms of engine safety. We recommend the crank hub modification for heavily tuned engines that put increased levels of strain on the crank hub and sprocket.