Go Fast Bits 08-14 WRX / 08-21 STI Underdrive Pulley Kit | 2014

This GFB Pulley Kit comes with the crank, alternator and power steering pulleys. Having large heavy pulleys spinning takes away power that is better spent moving the car. This kit takes care of that by replacing the crank pulley with a lighter version that underdrives the power steering and alternator yet leaves the A/C compressor spinning at normal speeds.

Total Mass for GFB Pulley Kit : 1.38lb
Total Mass for Stock Pulleys : 6.69lb (STI) / 5.81lb (WRX)
Mass Savings : 5.31lb (STI) / 4.43lb (WRX)

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