Go Fast Bits

Go Fast Bits Underdrive Pulley Kit Subaru Models

2015-2021 Subaru STI

Ships for free in the 48 states

SKU: 2014We price match!

Out of Stock

The Underdrive Pulley Kit promotes faster engine revs and more performance in the Subaru STI.
You will earn Reward Points with this Purchase.


Go Fast Bits Underdrive Pulley Kit


  • Lightweight aluminum construction
  • The crank pulley weighs .86 lbs
  • Power steering pulley weighs .37 lbs with 18% underdrive
  • Alternator pulley weighs .14 lbs with 16% underdrive
  • The total mass of the GFB pulley kit is 1.38 lbs
  • Mass savings for STI models: 5.31 lbs
  • Mass savings for WRX models: 4.43 lbs
  • AC compressor will still operate at normal speeds
  • Includes new belt
  • Black finish



The Go Fast Bits Underdrive Pulley Kit features lightweight aluminum construction. This kit will include a lightweight crank pulley, power steering pulley, and an alternator pulley. These are direct replacements for the factory pulleys and the weight savings will allow for a faster engine response with faster revs.

Additionally, these pulleys will come in an anodized black finish to add a clean look to the engine bay, making these pulleys a great performance and aesthetic upgrade. 

People who viewed this item also viewed

0 customer reviews

Average rating
(based on 0 reviews)
Ease of Installation
Fit / Quality
Overall Satisfaction

Write Your Own Review

Only registered users can write reviews. Please, log in or register


No questions have been asked about this product.

Upload images for this product