Speed Pulley Set = Supercharger, Lightened Crank & Overdrive Alternator Pulley
Want to add 20hp to your MINI Cooper S?
Your supercharged MINI has leeches! The Crank pulley that moves the belt, that spins the supercharger pulley and alternator, that puts the pressure on the engine, in order to get power out of a mini engine, is too heavy! So is the alternator pulley. They are cast in steel molds to keeps costs low for those more concerned about price than performance. We make our lightweight versions out of 6061 Aircraft aluminum. And instead of pouring a mold, we machine the pulley out of a solid bar.
Your supercharger also has the ability to produce a lot more boost, it just needs the right tools. Our stainless steel pulley is 15% smaller than the stock one to allow it to spin faster and create more power at your feet.
Fast Things Come in Small Packages:
The most popular modification to make to a MINI Cooper S is to add a reduction supercharger pulley. By reducing the size of this pulley the supercharger is able to create more pressure which it converts to power. Experience better boost for your buck with a bolt-on performance pulley made from powder-coated stainless steel.
Craven Speed is the only manufacturer utilizing "truform" tooth profile, to eliminate drive belt damage. Smooth and form-fitting teeth provide maximum surface area contact with the belt. It makes producing them take longer and cost more, but they do not cut corners.
The Craven Speed race tested pulley utilizes a 2 piece collet style design that locks the pulley to the shaft. Three bolts are used to ensure that the pulley is secured flat to the hub--because everybody knows that 3 points define a plane. These bolts are rated to hold 800lbs each and are used to activate the collet-type clamp. Once installed, there is almost no force whatsoever applied to the bolts.
It is widely accepted that this 15% size reduction pulley is the optimum balance between performance and engine longevity. It also leaves plenty of surface area so as to avoid slippage of the serpentine belt. Independantly raises boost about 4 psi and 18-20hp!!!
Bigger is Better (sometimes):
The Crank 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 uber-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) at the disposal 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 Craven Speed uses there Tru-form profile on all of the pullies they manufacture your belts will last longer.
All Craven Pulleys are precision CNC machined to +/- 0.001" in order to maintain better-than-factory balancing and minimize excess noise.
If your MINI also carries a high electrical load with aftermarket audio/video accessories, our overdrive alternator pulley will ensure that all the electronics maintain the proper charge.
You will save big $ at the speed shop by having all three (supercharger, crank, alternator) pulleys installed at the same time.
Fits R53 Mini Cooper S (02-06) |
