In 2002 Alta Performance was the first to introduce the two-piece, taper fit supercharger reduction pulley for the 02-06 Mini Cooper S; a design that has since become one of the most imitated on the market. What does it do? A smaller pulley increases the supercharger rotation speed per engine revolution, bumping boost output 3-5psi (depending on pulley size) over stock boost levels. This product features a simple design, inexpensive cost and is guaranteed to deliver 15-20hp at the wheels with no other modifications or ECU tuning required! What else could you ask for?
Alta supercharger reduction pulleys are offered in two sizes: 15% and 17% reductions. The 15% pulley is the market standard and produces smooth, safe power increases for a great daily driver. For those seeking a bit more power, the 17% is the best choice for those living on the edge. The 17% reduction builds boost at lower RPM's giving you even more power down low where you need it and 1.5lbs more boost at redline.
Also available is the Alta pulley removal too, designed to adapt a universal pulley removal tool to fit the factory pulley for easy removal during the installation of an Alta reduction pulley.