2004-2021 Subaru STI
2006-2021 Subaru WRX
2005-2012 Subaru Legacy GT
2005-2009 Subaru Outback XT
2006-2008 Subaru Forester XT
Note: 240mm upgrade. Must use ACT 240mm pressure plate and flywheel.
ACT 4-Puck Sprung Race Disc (4240518) for your Subaru Impreza WRX STI is a 4-pad spring-centered race disc made with high quality, ceramic friction materials. The engagement is harsher, but shifting is faster. the heavy duty torsional dampening springs are stronger, in most cases, than standard springs and are provided in the best sizes and spring rates to suit the application. The race disc features a heat-treated spring steel drive plate and is well-suited for the smaller disc sizes in smaller engines.
Feel - Aggressive engagement, quick shifts, OE to mild gear rattle
Recommended Use - Recommended for race use only
ACT Difference - High burst strength and holds 28% more torque than typical organic materials
Manufacturer Warranty - Limited Retail Warranty
Installation Instructions - ACT's General Installation Instructions
Can an ACT Race puck-style disc be used for daily driving, and is it recommended?
ACT's race discs are very aggressive and provide no-nonsense performance response. As a result, the engagement is harsh. Taking off from a stop can cause judder and/or an uncomfortable noise. These characteristics have no effect on the performance on the clutch or the drive line components. This type of disc should only be used in a professional race setting and never on the street. ACT always recommends using an organic disc on the street because it offers a smoother engagement and a longer lasting performance value for everyday drivers.
When should a clutch disc be replaced?
The majority of new discs measure .312-.315” (7.93 – 8.00mm) thick – fully worn is .275” (7.00mm) or below. A few applications (mostly Audi and BMW) start out at .332 - .335” (8.43 – 8.50mm). These are to be replaced when below .295” (7.50mm). It’s best to measure with a micrometer. Puck discs are measured as-is, where organic street discs are correctly measured by fully compressing the engagement cushion (marcel) between the linings. If the lining rivets on either side of the disc have made contact with the flywheel or pressure plate face, the disc must be replaced. Note: Using a disc that is thicker or thinner than the working range the pressure plate is designed for will have varying, and often very poor, results.