The Underdrive Pulley Kit promotes faster engine revs and more performance in the Subaru STI.

Go Fast Bits Underdrive Pulley Kit

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HIGHLIGHTS:

• 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

 

REDUCING ROTATIONAL MASS IN THE ENGINE ADDS HORSEPOWER

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.