Pulleys

Pulleys: crank, supercharger and underdrive parts that change how your accessories and blower spin

A pulley sits on the crank, alternator, water pump or supercharger snout and sets the speed those components turn at relative to the engine. Fit lightweight or underdrive pulleys and you cut rotating mass and can slow the accessories to free up a little crank effort. Swap a supercharger pulley to a smaller diameter and you spin the blower faster for more boost. This is a bolt-on job on most builds, but belt routing and tension have to be right or you'll throw a belt or chirp the accessories.

What ThreePiece stocks in pulleys

There are 44 products in this category, spanning 11 brands with current in-stock prices from $71 to $362. That range is what's live now, not a standing promise. Perrin Performance is the deepest, with 20 items, followed by Go Fast Bits and VMP Performance at 5 each, ATI at 4, and Fleece Performance, HKS, Aeromotive, BBK, GReddy, Torque Solution and Gates filling out the rest.

The line covers crank pulleys, alternator and water pump pulleys, multi-piece kits and supercharger pulleys. For a Subaru, the Perrin lightweight crank pulley for 19-21 WRX and 16-18 Forester and the GFB 3-piece lightweight kit for the BRZ / FR-S are good examples. The GFB underdrive/non-underdrive kit for 08+ WRX/STi tops the range at $361.53. On the forced-induction side, the ATI 8.46 supercharger pulley for the CTS-V LSA and the ATI 9.40 pulley for 2014+ LT1/LT4 cover GM blower motors, and the Aeromotive 28-tooth pulley handles belt-drive accessory needs.

How to choose

Decide what job you're doing first. A lightweight or underdrive crank pulley is about reduced mass and slowed accessories - most of the Perrin and GFB Subaru parts fall here. A supercharger pulley is a boost decision: the smaller-diameter ATI pulleys list overdrive percentages in their names, so match the diameter to how much extra blower speed your setup can safely take. Kits like the GFB 3-piece bundle crank, alternator and water pump pulleys together, which is tidier than sourcing them one at a time. Budget-wise, single crank pulleys sit toward the lower end while multi-piece kits and supercharger pulleys run higher.

What else you need with it

Plan for the belt and its hardware. Browse Bearings if you're refreshing the accessory drive, and check Fittings and Adapters for supporting hardware. Boost changes from a smaller blower pulley often lead to Fuel Pumps and cooling upgrades like Radiators. The full Engine Components section holds the rest.

Fitment and ordering

Fitment data is present on 23 of these parts, covering Subaru, Dodge, Nissan, Cadillac, Ford, Chevrolet, Pontiac and Scion across model years from 1984 to 2023 - including the Subaru WRX, WRX STI, BRZ, Impreza and Forester, Cadillac CTS-V, Chevrolet Camaro, Pontiac Firebird, Ford Mustang and Shelby GT500, Dodge 2500 and 3500, Nissan 300ZX and Scion FR-S. Verify year, make and model against the product listing before you buy. All orders ship free, and Affirm and Katapult financing is available - see financing. Not sure a pulley fits your engine? Call fitment help at 813-535-5801 or reach us through contact us.

Pulleys: crank, supercharger and underdrive parts that change how your accessories and blower spin

A pulley sits on the crank, alternator, water pump or supercharger snout and sets the speed those components turn at relative to the engine. Fit lightweight or underdrive pulleys and you cut rotating mass and can slow the accessories to free up a little crank effort. Swap a supercharger pulley to a smaller diameter and you spin the blower faster for more boost. This is a bolt-on job on most builds, but belt routing and tension have to be right or you'll throw a belt or chirp the accessories.

What ThreePiece stocks in pulleys

There are 44 products in this category, spanning 11 brands with current in-stock prices from $71 to $362. That range is what's live now, not a standing promise. Perrin Performance is the deepest, with 20 items, followed by Go Fast Bits and VMP Performance at 5 each, ATI at 4, and Fleece Performance, HKS, Aeromotive, BBK, GReddy, Torque Solution and Gates filling out the rest.

The line covers crank pulleys, alternator and water pump pulleys, multi-piece kits and supercharger pulleys. For a Subaru, the Perrin lightweight crank pulley for 19-21 WRX and 16-18 Forester and the GFB 3-piece lightweight kit for the BRZ / FR-S are good examples. The GFB underdrive/non-underdrive kit for 08+ WRX/STi tops the range at $361.53. On the forced-induction side, the ATI 8.46 supercharger pulley for the CTS-V LSA and the ATI 9.40 pulley for 2014+ LT1/LT4 cover GM blower motors, and the Aeromotive 28-tooth pulley handles belt-drive accessory needs.

How to choose

Decide what job you're doing first. A lightweight or underdrive crank pulley is about reduced mass and slowed accessories - most of the Perrin and GFB Subaru parts fall here. A supercharger pulley is a boost decision: the smaller-diameter ATI pulleys list overdrive percentages in their names, so match the diameter to how much extra blower speed your setup can safely take. Kits like the GFB 3-piece bundle crank, alternator and water pump pulleys together, which is tidier than sourcing them one at a time. Budget-wise, single crank pulleys sit toward the lower end while multi-piece kits and supercharger pulleys run higher.

What else you need with it

Plan for the belt and its hardware. Browse Bearings if you're refreshing the accessory drive, and check Fittings and Adapters for supporting hardware. Boost changes from a smaller blower pulley often lead to Fuel Pumps and cooling upgrades like Radiators. The full Engine Components section holds the rest.

Fitment and ordering

Fitment data is present on 23 of these parts, covering Subaru, Dodge, Nissan, Cadillac, Ford, Chevrolet, Pontiac and Scion across model years from 1984 to 2023 - including the Subaru WRX, WRX STI, BRZ, Impreza and Forester, Cadillac CTS-V, Chevrolet Camaro, Pontiac Firebird, Ford Mustang and Shelby GT500, Dodge 2500 and 3500, Nissan 300ZX and Scion FR-S. Verify year, make and model against the product listing before you buy. All orders ship free, and Affirm and Katapult financing is available - see financing. Not sure a pulley fits your engine? Call fitment help at 813-535-5801 or reach us through contact us.