The max RPM limit of aftermarket alternators can be around the 18000 alternator RPM mark. This works great for most factory applications until you start building engines that exceed factory RPM. Once the alternator reaches its max RPM it stops charging and your voltage drops, as well as potentially reducing the life of the alternator with the higher RPM. This oversized pulley from Aeroflow Performance will solve this issue.

Specifically designed to suit Aeroflow Ford and Chevy OEM style alternators. This oversized alternator pulley is also required in high-RPM engines (6000 + Engine RPM) to slow down the RPM of the alternator to prevent it from prematurely failing. This is a quick and easy install by removing the pulley and installing this directly on.