The Crank Pulley that moves the belt, that spins the supercharger pulley, that adds the pressure on the engine, in order to get power out of a mini engine, is too heavy! This 7 lb weight that the engine has to spin every time you rev the engine is robbing power that could be much better spent on making the car get up and go. The Detroit Tuned 2% Crank Pulley is severely lightened to cut rotating mass. Compare the 7lbs. weight of the Cooper S model crank pulley to a mere .875 lb. on the Detroit Tuned lightened pulley.
Bigger IS Better
This Pulley is 2% over sized to drive your supercharger faster by altering the ratio between the size of your supercharger pulley and that of the crank pulley. When combined with the very popular 15% reduction supercharger pulley a synergistic effect is achieved. The ratio is exaggerated such that much less energy is required to spin more revolutions. The result is increased pressure (psi)(boost) out of the supercharger. Experts have likened the results to using a much smaller supercharger pulley, like a 19% reduction. By increasing the size of the crank instead you can retain the stock sizing on your belt. Since we use out Tru-form profile on all of the pullies we manufacture your belts will last longer.
All Detroit Tuned Pulleys are precision CNC machined to +/- 0.001" in order to maintain better-than-factory balancing and minimize excess noise.
Note: Will only fit R52/R53 MINI Cooper S's.