Spec Stage 4 Clutch Kit Scion FR-S 2013-2016 / Subaru BRZ 2013-2020 vendor_Mooresport They are a common upgrade

They are a common upgrade in K-series engine builds where OEM valves become a limiting factor under increased power and RPM

The Perrin lightweight crank pulley lightens up your rotating engine parts to free up power

Mishimoto has developed silicone couplers which can be used with a variety of pipe sizes and bends

maximizing traction on power out

03-07 Impreza NA Front and Rear

Spec Stage 4 Clutch Kit Scion FR-S 2013-2016 / Subaru BRZ 2013-2020 vendor_Mooresport They are a common upgradePart #: SU334 The SPEC Stage 4 is a solid hub version of the Stage 3. The hub is solid 8 rivet and the assembly is heat treated for strength and durability. It is available in 6 puck for the smooth engagement. The Stage 4 is street drivable but not street friendly due to the rigid hub. Best for dedicated drag racing, road racing, rally or drift cars. Not suggested for any street driven BRZ. Features: Not recommended for street driving. Harsh