ACT Performance Street Disc for the 2004-2021 Subaru WRX STI, SB4 Replacement

The ACT Performance Street Sprung Organic Replacement Disc for 2004-2021 Subaru WRX STI (SB4) is a standalone replacement disc compatible with ACT clutch kits and most OEM pressure plates on this application. Use case: street replacement, performance street builds.

DETAILS

• Disc type: performance street sprung organic
• Engagement: street
• Use case: street replacement, performance street builds
• Compatibility: 2004-2021 Subaru WRX STI (SB4)
• Chrome-moly hub, heat-treated

Premium organic friction material with high copper content for improved heat transfer. Steel-backed lining for greater burst strength. Sprung center hub for smooth, quiet engagement.

ACT replacement discs use the same friction materials and hub specifications as the discs included in ACT complete clutch kits. Ordering a replacement disc is the correct approach when the pressure plate is still serviceable and only the friction material is worn. Verify the specific disc reference number against your existing ACT kit to confirm compatibility.

What’s in the Box

• ACT replacement clutch disc
• Installation instructions

Why Choose ACT

Advanced Clutch Technology has been manufacturing performance clutch systems in the United States since 1993. Every ACT pressure plate uses a proprietary diaphragm design that increases clamp load and reduces deflection compared to OEM units, and every diaphragm goes through a four-stage heat-treating process before it leaves the factory. The result is a clutch system that holds more power than the stock unit, engages more precisely, and lasts longer under the kind of driving that wears factory clutches out quickly. ACT designs each application from scratch rather than modifying OEM tooling, which means the fitment is precise and the performance is intentional. Whether the build is a street-driven daily driver or a dedicated track car, ACT offers a kit at the correct specification for the use.

The RallySport Take

ACT replacement discs allow you to replace the friction material in your existing ACT clutch setup without replacing the full system. If the pressure plate is still serviceable and in good condition, a standalone disc is the correct approach it is less expensive than a full kit and produces the same result. The street disc is the ACT friction specification for this application. Verify your existing ACT kit’s disc reference number matches before ordering. Fits Subaru applications 2004-2021.

Fitment