We have re-designed our WRX lightweight pulley (part #2009) to provide even more benefits.
It is now shaped to look exactly like the factory Subaru pulley, so it goes unnoticed in your engine bay - it even uses the factory belts.
A significant amount of weight has been removed from around the rim for even better throttle response. The 2009 pulley now weighs in at 1 1/4 lbs. compared to the factory 4 3/4 lbs. on the WRX and 5 1/2 lbs. on the STi.
This pulley will improve throttle response (particularly off-boost response) and allow the engine to rev more freely in the upper rev range. It suits ALL Subaru EJ-series engines, and does not require additional belts.
Install a GFB light-weight 6061 T6 aluminum billet with OE dimensions without the weight and get better throttle response and more power!
Manufactured in Australia!
How do they do this?
1. Less weight - GFB's pulleys are manufactured on the latest Multi-Axis CNC machines from the highest grade 6061-T6 aluminium billet, making them immensely lighter than their factory steel counterparts. This lower weight yields a large reuction in the rotating inertia of the belt train, allowing the engine to accelerate faster. The effect is similar to fitting a lightened flywheel and is particularly noticeable in the lower RPM range before the turbo spools up. This is because the power required to accelerate a heavy pulley accounts for a much greater proportion of the available power at low RPM.
2. This replacement pulley is a NON UNDER DRIVE engine CRANK PULLEY and is a light weight replacement for the original equipment pulley. Fits all Subaru EJ20 and EJ25 engines.