Evosport - Under-Drive Pulley Kit, Performance, BMW E39 525/528/530

Engineered not only to be the best pulley kits on the market, but to provide the best compromise between performance and reliability for your BMW! Specifically, we have designed them to underdrive the water pump, power steering pump and alternator*. These kits provide 10%-20% overall reduction in driving your car's systems and have been dyno tested to provide up to 12hp gain!

*Alternator pulleys - we offer two kits, one for the performance minded individual and one for the serious audiophile. If you have a significant additional load on the alternator from aftermarket audio amplifiers, you will not want to underdrive the alternator. Thus, we simply lighten that pulley rather then underdrive it. Select the type of alternator from the drop down menu.