Lightweight Pulley Kits

GFBs 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.

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.

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.

GFB Subaru WRX Non-underdrive Crank Pulley


We have re-designed our WRX lightweight pulley 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 578g (previously 790g), compared to the factory 2180g on the WRX and 2575g 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.

£127.51£106.26 (ex. VAT)

GFB Lightweight Crankshaft Pulley for Subaru BRZ and Toyota GT86


Specifically designed to fit Subaru BRZ / Toyota GT86 / Scion FR-SMade from aircraft-grade 6061-T6 aluminiumImproved acceleration by reducing the roatational mass of the crankshaftDesigned to improve performance without sacrificing reliability or engine longevityWe've designed our lightweight crank pulley specifically to fit the Subaru BRZ, Toyota GT86 and Scion FR-S.GFB lightweight pulley kits are made from aircraft-grade 6061-T6 aluminium and offer faster acceleration through significant weight reduction on the crankshaft.Most of our kits are underdriven, which means the accessories are driven slightly slower to reduce parasitic losses. GFB pulley kits are designed to improve acceleration by reducing the rotational mass (inertia) on the crankshaft as well as parasitic loads from the driven accessories. The effect is similar to a lighter flywheel, and the engine feels more lively and willing to rev.We know that people are sometimes concerned about possible adverse effects of lightweight pulleys and underdriving, but rest assured we have done our homework! The underdrive ratios have been optimised to ensure there are NO adverse effects on the performance of the accessories, and whilst it is true that some engine types do suffer harmonic issues from lightweight pulleys, we steer clear of those. The kits we release are thoroughly application tested and do NOT cause engine damage in the short or long term.

£133.75£111.46 (ex. VAT)

GFB Lightweight Crank and Alternator Pulley Kit


Lightweight pulley kit to suit '98-'03 Subaru WRX, STI & Outback B4 Includes 2 pulleys and high performance engine belts Made from anodized, aircraft-grade aluminium Suits Bugeye WRX and STI models as well as Outback / Liberty B4 2.0 Turbo engines.

£181.57£151.31 (ex. VAT)

GFB Lightweight Pulley Kit


GFB lightweight Under-Drive Pulley Kits have been designed to improve acceleration by reducing the rotational mass on the crankshaft. Engineered using premium quality 6061 T6 Billet Aluminium on Precision CNC machines, GFB lightweight pulley kits typically save up to 2.5kg of weight over the factory pulleys. Testing revealed that the minimum improvements after replacing the factory pulleys with GFB lightweight Under-Drive Pulleys were as follows:- 3% faster (0.1 seconds) from 30-90 km/h- 4% higher average G-Force (0.02g) from 30-90 km/h- 7.2% higher G-Force (0.03g) at 40km/h (2800 RPM)- 5kW peak power increase (173.7kW to 178.7kW)

£249.48£207.90 (ex. VAT)

GFB Lightweight Pulley Kit

GFB lightweight Under-Drive Pulley Kits have been designed to improve acceleration by reducing the rotational mass on the crankshaft. Engineered using...