Go Faster? Add Lightness, GFB's Lightweight Pulley Kits offer sharper throttle response and faster acceleration by significantly reducing the rotating mass at the engine. Made from a single billet of 6061-T6 aluminium, then precision CNC machined to exacting tolerances, our pulley kits offer an exceptional bolt-on performance advantage without the need for supporting mods or tuning. It might be hard to imagine how reducing the mass of a pulley makes a car go faster, but accelerating a heavy factory pulley from say 3000-7000 RPM in a second or two saps a measurable amount of torque. GFB Lightweight Pulleys reduce inertia by up to 85%, so most of the torque that used to accelerate the pulley can now be applied to the wheels.. In some vehicle applications additional performance benefits are available at high RPM by underdriving the accessories (slowing them down), which reduces the parasitic load on the engine. All underdriven kits are thoroughly tested to ensure that the benefit comes without compromising the accessory performance. Sharper Throttle Response and “urge”, engine feels more lively and willing to rev, up to 85% rotating inertia reduction, will not cause engine damage, no negative effects on driven accessory performance. 3-piece underdrive pulley kit (Crank, alternator & power steering pulleys & belts.. 3-piece underdrive pulley kit (Crank, alternator & power steering pulleys. GFB 99-00 Subaru WRX/Forrester GT Light-Weight Engine Pulley Kit. Subaru Suits WRX/STi MY99-00, Forester GT MY01-02). Engine Under Drive Pulley Kit. GFB Pulley Kit. Pulley Kit

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