The T1S-S05 Mod-Twin 225 HD Sprung Street Kit is engineered for high-powered AWD street cars, combining twice the organic friction surface area with an ultra-durable spring-center Mono-Drive hub in a fully modular design. Each diaphragm spring goes through ACT's exclusive four-stage heat-treating process for a consistent, light pedal feel, while steel-backed friction plates deliver a stable friction coefficient, strong heat capacity, and long clutch life. The Mono-Drive sprung hub assembly extends input shaft life and reduces driveline shock from torsional vibration. The kit includes a CNC-machined, dynamically balanced flywheel, pressure plate cover, diaphragm spring, puck-style ceramic friction plates, sprung Mono-Drive hub assembly, floater, patented Monoloc Collar, release bearing, alignment tool, and pilot bearing if needed. Mod-Twin clutches are fully rebuildable and most components can be ordered separately.
WarrantyInstallation Instructions
Specifications
- Kit Type: Mod-Twin 225, HD Sprung Street
- Torque Capacity: 700 ft-lbs
- Hub: Sprung Mono-Drive
- Included Components: Flywheel, pressure plate cover, diaphragm spring, ceramic friction plates, sprung hub, floater, Monoloc Collar, release bearing, alignment tool
- Warranty: 1-year ACT limited warranty
- Part Number: T1S-S05
Vehicle Applications
| Year | Make | Model | Trim |
|---|---|---|---|
| 2004 | Subaru | Impreza | WRX STI |
| 2005 | Subaru | Impreza | WRX STI |
| 2006 | Subaru | Impreza | WRX STI |
| 2007 | Subaru | Impreza | WRX STI |
| 2007 | Subaru | Impreza | WRX STI Limited |
| 2008 | Subaru | Impreza | WRX STI |
| 2009 | Subaru | Impreza | WRX STI |
| 2010 | Subaru | Impreza | WRX STI |
| 2010 | Subaru | Impreza | WRX STI Special Edition |
| 2011 | Subaru | Impreza | WRX STI |
| 2011 | Subaru | Impreza | WRX STI Limited |
| 2012 | Subaru | Impreza | WRX STI |
| 2012 | Subaru | Impreza | WRX STI Limited |
| 2013 | Subaru | Impreza | WRX STI |
| 2013 | Subaru | Impreza | WRX STI Limited |
| 2014 | Subaru | Impreza | WRX STI |
| 2014 | Subaru | Impreza | WRX STI Limited |
| 2015 | Subaru | WRX STI | Base |
| 2015 | Subaru | WRX STI | Launch Edition |
| 2015 | Subaru | WRX STI | Limited |
| 2016 | Subaru | WRX STI | Base |
| 2016 | Subaru | WRX STI | Limited |
| 2016 | Subaru | WRX STI | Series.HyperBlue |
| 2017 | Subaru | WRX STI | Base |
| 2017 | Subaru | WRX STI | Limited |
| 2018 | Subaru | WRX STI | Base |
| 2018 | Subaru | WRX STI | Limited |
| 2018 | Subaru | WRX STI | Type RA |
| 2019 | Subaru | WRX STI | Base |
| 2019 | Subaru | WRX STI | Limited |
| 2019 | Subaru | WRX STI | S209 |
| 2020 | Subaru | WRX STI | Base |
| 2020 | Subaru | WRX STI | Limited |
| 2021 | Subaru | WRX STI | Base |
| 2021 | Subaru | WRX STI | Limited |
Frequently Asked Questions
What torque capacity does the T1S-S05 handle?
The T1S-S05 Mod-Twin 225 HD Sprung Street kit is rated for up to 700 ft-lbs of torque.
What is the Mono-Drive sprung hub?
It is a spring-center hub assembly that dampens torsional vibration, protecting the input shaft and reducing driveline shock compared to a rigid hub.
Can the T1S-S05 be rebuilt?
Yes. Mod-Twin clutches are fully rebuildable and most components, including the friction plates and hub assembly, can be ordered separately.
Which Subaru models does the T1S-S05 fit?
It is confirmed for Subaru Impreza WRX STI and WRX STI-badged models across the years listed in the Vehicle Applications table.
