The ACT SB10-HDSS pairs ACT's Heavy Duty pressure plate with its Performance Street sprung disc and ACT's patented Monoloc for the Subaru WRX STI and Legacy GT spec.B. The Heavy Duty pressure plate uses ACT's exclusive diaphragm design to increase clamp load and reduce deflection, with every diaphragm going through a four-stage heat-treating process. The Performance Street disc uses premium organic friction material with high copper content for improved heat transfer and steel-backed lining for durability, with reduced marcel for faster shifts. Monoloc is a one-piece, direct replacement for the standard two-piece wedge collar and wire ring used in pull-type clutches; its hardened chrome-moly construction provides uniform loading on the bearing and pressure plate regardless of driver influence or vehicle modifications.
Specifications:
- Torque Capacity: 522 ft-lb (45% over OE)
- Product Weight: 18.2 lbs
- Disc Diameter: 9.4 in (240 mm)
- Pressure Plate: Heavy Duty, four-stage heat-treated diaphragm
- Disc Material: Organic, high-copper content, steel-backed lining
- Disc Style: Sprung hub
- Includes: ACT Monoloc, chrome-moly construction
- Pedal Feel: Light to moderate effort, smooth positive engagement, OE to mild gear rattle, confidence during hard shifts
- Recommended Use: Street and race use
- Part Number: SB10-HDSS
Vehicle Applications:
- 2004 Subaru Impreza WRX STI
- 2005 Subaru Impreza WRX STI
- 2006 Subaru Impreza WRX STI
- 2007 Subaru Impreza WRX STI
- 2008 Subaru Impreza WRX STI
- 2009 Subaru Impreza WRX STI
- 2010 Subaru Impreza WRX STI
- 2011 Subaru Impreza WRX STI
- 2012 Subaru Impreza WRX STI
- 2013 Subaru Impreza WRX STI
- 2014 Subaru Impreza WRX STI
- 2010 Subaru Impreza WRX STI Special Edition
- 2007 Subaru Legacy GT spec.B
- 2008 Subaru Legacy GT spec.B
- 2009 Subaru Legacy GT spec.B
- 2013 Subaru WRX STI
- 2014 Subaru WRX STI
- 2015 Subaru WRX STI
- 2016 Subaru WRX STI
- 2017 Subaru WRX STI
- 2018 Subaru WRX STI
- 2019 Subaru WRX STI
- 2020 Subaru WRX STI
- 2021 Subaru WRX STI
- 2015 Subaru WRX STI Launch Edition
- 2015 Subaru WRX STI Limited
- 2016 Subaru WRX STI Limited
- 2017 Subaru WRX STI Limited
- 2018 Subaru WRX STI Limited
- 2019 Subaru WRX STI Limited
- 2020 Subaru WRX STI Limited
- 2021 Subaru WRX STI Limited
- 2016 Subaru WRX STI Series.HyperBlue
- 2017 Subaru WRX STI Sport
- 2018 Subaru WRX STI Sport
- 2019 Subaru WRX STI Sport
- 2020 Subaru WRX STI Sport
- 2021 Subaru WRX STI Sport
- 2014 Subaru WRX STI Tsurugi Edition
- 2018 Subaru WRX STI Type RA
Warning: This product can expose you to chemicals including carbon black, glass wool fibers, or silica (in clutch discs), chromium and nickel, which are known to the State of California to cause cancer or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov
FAQ
What torque capacity does the SB10-HDSS handle?
The kit is rated for 522 ft-lb of torque capacity, a 45% increase over the factory clutch.
What is Monoloc and why is it included?
Monoloc is ACT's patented one-piece replacement for the standard two-piece wedge collar and wire ring in pull-type clutches. Its chrome-moly construction provides uniform, consistent loading on the bearing and pressure plate for longer release mechanism life.
What vehicles does the SB10-HDSS cover?
It covers the Subaru Impreza WRX STI and WRX STI (2004-2021) plus the Legacy GT spec.B (2007-2009). See the Vehicle Applications list above to confirm the exact year and trim.
Is this kit suitable for daily driving?
Yes. It is engineered for light to moderate pedal effort with smooth, positive engagement and only OE to mild gear rattle, and is recommended for both street and race use.
