For a minimal amount of money, the MINI Cooper S Supercharger Pulley can make even the Monday commute seem like a run around Laguna Seca. The stock pulley is one of the first things BMW MINI Cooper S owners replace to increase the performance of their car. 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. More boost=bigger grin! 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. MINI Cooper S tuners, including the venerable John Cooper Works, have extensively tested the 15% reduction supercharger pulley and found it to be ideal for street and track use. For the even more adventurous, changing to a 19% reduction pulley will have the boost kicking in 750rpm sooner than the 15% pulley. The 19% Mini Cooper S Supercharger Pulley is ideal for street driving conditions ONLY! It is not recommended for the long high revving situations typically seen on the racetrack! Sustained 6000-7600rpm generates more heat reducing the 19% pulley's effectiveness. Be sure to see our article on installing an underdrive pulley on the MINI Cooper S as well. It's also a good idea to runa set of colder heat range spark plugs with the underdrive pulley to help prevent detonantion that might occur from the increased boost temperatures. You will also need to use the shorter length serpentine belt from the John Cooper Works cars for optimal results.
Madness Motorworks 15% Reduction Underdrive Pulley, Cooper S (2002-06), Cooper S Conv. (2005-08) Brand: Madness Motorworks [More Info]
Madness Motorworks 19% Reduction Underdrive Pulley, Cooper S (2002-06), Cooper S Conv. (2005-08) Brand: Madness Motorworks [More Info]
Madness Motorworks EZ Pulley Puller, Cooper S (2002-06), Cooper S Conv. (2005-08) Brand: Madness Motorworks [More Info]
NGK BKR7EQUP Colder Heat Range Spark Plug, For Use With Underdrive Pulley (4 per car, sold individually), Cooper S (2002-06), Cooper S Conv. (2005-08), Each Brand: NGK [More Info]
Serpentine Belt, For Cars With John Cooper Works Package Or for use with Underdrive Pulley, Cooper S (2002-06), Cooper S Conv. (2005-08) Brand: Contitech [More Info]