Spinning your alternator passed the factory limit often leads to failure. Extend your alternator’s life by reducing its maximum RPM while maintaining sufficient charge at idle. Our 18% underdrive alternator pulley will help keep the rpms within a more reasonable range when spinning past the factory limiter.  Our pulleys are CNC machined from billet 6061 aluminum and are hard black anodized for a durable finish.

70mm OD (measured at top of rib) 

*Includes  replacement nut

*Requires larger belt