Product Details: Install a GFB light-weight under-drive pulley kit and get better throttle response and more power!

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. Under-driving - Additional power increases also come from making the crank pulley smaller, thereby slowing down the accessories and reducing the driven load (particularly at high RPM), without affecting their operation.

Fits:

Subaru WRX MY94-96
    -2001 and 2003 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

MY97-98 WRX and Version 3-4 STi
    -2001 and 2003 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

MY99-00 WRX and Version 5-6 STi
    -2001 and 2003 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

MY01-02 (MY02-03 in the U.S.) WRX and STi ("bugeye")
    -Note that the power steering pulley is not removable in this model, hence only the 2001 two-pulley (crank and alternator) kit fits. 2001 kit includes the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

MY03-current (MY04-current in the U.S.) WRX and STi
    -2001 and 2003 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

Subaru Forester GT (MY98 - 00)
    -2001 and 2201 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

Subaru Forester GT (MY01 - 02)
    -2001 and 2201 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

Subaru Forester XT (MY03 - 04)
    -2001 and 2201 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

Subaru Forester XT (MY05 onwards)
    -2001 and 2201 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.

Subaru Liberty/Legacy GT (MY03 onwards)
    -2001, 2201 and 2010 kits include the required shorter belts. 2009 is the same diameter as factory and therefore uses the original belts.