Way Motor Works has your fix for a broken crank pulley, or soon to fail crank pulley. The ATI Super Damper is the best replacement for the stock harmonic balancer on your supercharged R52 or R53 Cooper S. I'd say once a week we see one of these failed. When this happens the car will go into limp mode and your stuck with a tow bill. And if your tracking the car the extra heat will induce a failure. The ATI damper also seems to make the MINI idle smoother and bearings last longer. This is the same pulley I use on my race car and the RSR race team uses. too