Clutch Masters 850 PRO Series Twin Disc Clutch Kit & Flywheel 06-09 Legacy / 04-21 STI | 8.5" Twin Disc | High-Torque Clutch Kit
Overview
The Clutch Masters 850 PRO Series Twin Disc Clutch Kit & Flywheel is a high-performance conversion kit designed specifically for the 2006-2009 Subaru Legacy and 2004-2021 Subaru WRX STI. This kit replaces the OEM flywheel and clutch setup with a purpose-built system engineered to handle extreme torque and aggressive driving conditions. Ideal for enthusiasts pushing their Subaru’s power limits, this clutch kit offers a significant upgrade in strength, durability, and engagement precision.
Built as the next evolution of Clutch Masters’ multi-disc clutch technology, the 850 PRO Series features a completely redesigned 8.5-inch clutch system. It incorporates advanced materials and engineering solutions such as 12 heat-treated 4140 steel stands and a 12-point nut and stud mounting system, replacing the traditional 6-post aluminum design. This approach eliminates flex and wear issues common in high horsepower applications, ensuring reliable performance on both street and track.
Subaru owners will appreciate the real-world benefits of this clutch kit’s design, including a next-generation driven hub that reduces spline wear and improves transmission input shaft alignment. The kit’s ceramic friction discs provide consistent engagement and heat resistance, making it suitable for serious street performance and competitive motorsports. With options for billet aluminum or steel flywheels, this kit offers flexibility to match your build’s strength and weight requirements.
Features & Specifications
This Clutch Masters 850 PRO Series Twin Disc Clutch Kit & Flywheel is engineered for Subaru Legacy and WRX STI platforms and features an 8.5-inch twin ceramic disc setup. Constructed from heat-treated 4140 steel and billet aluminum or steel flywheels, it delivers exceptional torque capacity and durability for Subaru enthusiasts seeking aggressive street and track performance.
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Brand: Clutch Masters
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Product: 850 PRO Series Twin Disc Clutch Kit & Flywheel
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Part Number: 15017PTD80SHV
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Fitment: 2006-2009 Legacy / 2004-2021 STI
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Material: 4140 Heat-Treated Steel (clutch), 6061-T6 Billet Aluminum or 1045 Billet Steel (flywheel)
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Finish: Type 3 Hard Coat Anodized (aluminum flywheel), Black Oxide (steel flywheel)
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Construction: 12-Point Nut and Stud Mounting, Precision Machined
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Origin: Made in USA
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Torque Capacity: 800 ft.lbs (estimated)
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Clutch Disc Configuration: Twin Disc Ceramic Friction
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Available Stages: Sprung Race (PTD80), Rigid Race (PTD8R)
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Flywheel Options: Billet Aluminum or Billet Steel
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Serviceability: Fully Serviceable with Rebuild Kits Available
Key Benefits
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Performance: Handles up to 800 ft.lbs of torque, ideal for high horsepower builds and aggressive driving.
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Durability: Heat-treated 4140 steel construction resists flex and wear under extreme conditions.
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Fitment: Designed exclusively for Subaru Legacy (06-09) and WRX STI (04-21) with a dedicated flywheel for perfect compatibility.
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Engagement: Ceramic friction discs provide consistent, smooth engagement with reduced spline wear thanks to the next-gen driven hub.
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Adjustability: Choice between sprung and rigid race disc configurations to match driving style and vehicle setup.
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Quality: Proudly manufactured in the USA with rigorous quality control and race team input.
What's Included
- 1× Clutch Masters 850 PRO Series Twin Disc Clutch Kit
- 1× Clutch Masters Billet Aluminum or Steel Flywheel (application-specific)
- Mounting hardware for clutch and flywheel installation
- Installation instructions
Installation & Compatibility
Installation of the Clutch Masters 850 PRO Series Twin Disc Clutch Kit & Flywheel is a moderate to advanced mechanical task best suited for experienced DIYers or professional shops. The kit requires removal of the transmission and replacement of the OEM flywheel, which is not compatible with this clutch system. No special tools beyond standard clutch alignment and transmission tools are required, but care must be taken to ensure proper torque specs and alignment during installation. Tuning is recommended after installation to optimize clutch engagement and drivability, especially on modified vehicles.
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Professional Installation: Recommended
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Modifications Required: OEM flywheel must be replaced; clutch master flywheel required
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Verify Compatibility: Confirm fitment for your specific year and trim level of Legacy or WRX STI
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