Fitment Information: This ACT 4 Pad Sprung Race Disc (4228218) fits 2002 - 2018 Subaru WRX, 2005 - 2012 Subaru Legacy GT, 2005 - 2009 Subaru Outback XT, and 2004 - 2008 Subaru Forester XT. Note that starting mid - 2018MY production with VIN J*806877, Subaru used 240mm clutch components, and this ACT disc isn't compatible with the revised OEM parts. Features: Made of high - quality ceramic friction materials, this 4 - pad spring - centered race disc offers a harsher engagement but faster shifting. The heavy - duty torsional dampening springs are stronger than standard ones and are sized and rated perfectly for the application. It has a heat - treated spring steel drive plate, ideal for smaller engines. Feel: Aggressive engagement, quick shifts with OE to mild gear rattle. Recommended Use: For race use only. ACT Difference: It has high burst strength and can hold 28% more torque than typical organic materials. FAQ: Can an ACT Race puck - style disc be used for daily driving? It's not recommended. ACT's race discs are aggressive, with a harsh engagement. Starting from a stop may cause judder or noise. They're for professional race settings only. ACT suggests using an organic disc on the street for smoother engagement and long - lasting performance. When to replace a clutch disc? Most new discs are 0.312 - 0.315” (7.93 – 8.00mm) thick, and fully worn is 0.275” (7.00mm) or below. Some applications start at 0.332 - 0.335” (8.43 – 8.50mm) and should be replaced below 0.295” (7.50mm). Measure with a micrometer. Puck discs are measured as is, while organic street discs are measured by compressing the engagement cushion. Replace the disc if the lining rivets touch the flywheel or pressure plate. Using a disc outside the pressure plate's working range can lead to poor results.
Using the ACT 4 Pad Sprung Race Disc: This disc is designed for race use only, so make sure you're in a professional race setting before installing it. It's not suitable for daily driving on the street. When installing, ensure it fits your specific Subaru model as described in the fitment information. Note that starting from mid - 2018MY production with a certain VIN, the disc won't work with the revised OEM parts. Maintenance: Regularly check the disc's thickness with a micrometer. Most new discs start at 0.312 - 0.315” (7.93 – 8.00mm) and should be replaced when they reach 0.275” (7.00mm) or below. For some models, the replacement thickness is different, so follow the provided guidelines. Also, keep an eye on the lining rivets. If they touch the flywheel or pressure plate, it's time to replace the disc. Using a disc that's too thick or thin for the pressure plate can cause problems, so always measure correctly and replace as needed.
