Craven Speed 15% Pulley for R53 Mini Cooper S This Pulley was custom stamped for the Grassroots Garage, For a minimal amount of money, the MINI Cooper S Supercharger Pulley The stock pulley is one of the first things R53 MINI Cooper S owners replace to increase the performance of their car. Just do the research on the forums. Changing to a 15% smaller supercharger pulley on an otherwise stock motor has been shown, through independent testing, to provide increases of 15-20 horsepower with similar increases in torque. The smaller supercharger pulley causes the unit to spin faster and create more boost. Stock Mini Cooper S engines will see a 3-4 pound increase in boost. Add to that a modified intake or exhaust and your Mini Cooper S will have even bigger power gains. There simply is no greater bang for the buck out there. Retails New $109 Plus shipping . This lightly used for approx 1000 miles, in excellent condition for $85 shipped. (in CONUS USA Only) Paypal Only. More info about the pulley in below links Supercharger Pulley - CravenSpeed Online Craven Speed 15% Supercharger Pulley - Way Motor Works