Description Reviews Here is the best bang for your buck for the supercharged cars. You get the most HP vs. dollars spent! When you put a smaller pulley on your MINI's supercharger, it spins faster. When the supercharger pulley spins faster, it creates more pressure (psi). When the supercharger has more pressure, the engine gets more boost. More boost = more speed! Our supercharger pulleys are machined to a 15% reduction of the original pulley on your MINI's supercharger. It is widely accepted that 15% is a safe size reduction on this particular supercharger. Our pulleys will neither eat or throw your belt, so you can be confident it will last the life of your car. This pulley is self centering and is made so you will not get any excessive belt noise. Note: To use this pulley correctly, you will need a shorter belt and colder heat range plugs. See our pulley kit for the full package. Got any questions? Give us a call! Note: We recommend a professional install for this part. You will need a pulley puller and a belt tensioner tool, as well as a few other tools (like 2 jacks) to do this job. But we rent the tools here on our website should you want to do it on your own.