Lightened underdrive pulley kit (3 pulleys and belts included)

Lightweight aircraft grade alumimium Lightened underdrive pulley kit (3 pulleys and belts included) also suits: SUBARU GT MY98-00
SUBARU Impreza 2.0 Turbo GT EJ20T MY94-00
SUBARU WRX MY97-98

GFB machines its lightweight pulley kits from aircraft-grade 6061-T6 aluminium and boosts acceleration by significantly reducing crankshaft weight. Most Go Fast Bits kits use an underdrive design, slowing accessory speeds slightly to cut parasitic losses. These pulley kits improve acceleration by reducing rotational mass (inertia) on the crankshaft and easing the load from driven accessories.

This setup delivers a similar effect to a lighter flywheel, making the engine feel more responsive and eager to rev. GFB optimises the underdrive ratios to maintain full accessory performance. While some engines can experience harmonic issues with lightweight pulleys, GFB avoids those applications. The team thoroughly tests every kit for its intended use, ensuring it won’t cause engine damage in the short or long term.