PERRIN 06-14 Subaru WRX / 07-21 STI / 06-13 Forester Lightweight Alternator Pulley - Blue

This Perrin alternator pulley is made from a solid piece of billet aluminum, then anodized blue. By reducing the rotational mass on your engine's accessory belt system, you'll notice a slight improvement in how quickly the engine revs up. It's a simple, well-built part that's a popular choice for Subaru owners looking to shave a little weight and improve engine response. The anodized finish also adds a nice touch under the hood.

Swapping out the stock alternator pulley for this lighter one is a straightforward job. It fits right onto your existing belt system without needing any special modifications. While it won't drastically change your car's performance, it's a nice little addition that contributes to a more responsive feel, especially when you're driving spiritedly.