2004-2007 Subaru STI / 2006-2007 Subaru WRX 3-piece underdrive pulley kit by Go Fast Bits (2010) Go Fast Bits

GFB Pulley Kit:

GFB lightweight pulley kits are made from aircraft-grade 6061-T6 aluminium and offer faster acceleration through significant weight reduction on the crankshaft. The effect is similar to a lighter flywheel, and the car feels more lively and willing to rev.

Most of their kits are underdriven, which means the accessories are driven slightly slower to reduce parasitic losses.

Features

• Improved throttle response and acceleration through significant reduction of rotating mass
• Engine feels more free-revving
• Under-driven kits offer more power through reduction of parasitic losses from the accessories with NO adverse affects on their operation