ACT Mod-Twin 225 Extreme Duty Sprung Race Twin Disk Clutch Kit 2004-2021 STI

The Mod-Twin 225 XT Sprung Race Kit is designed for high-powered AWD vehicles, delivering aggressive launches and smoother shifting. It combines twice the ceramic friction surfaces with an ultra-durable Mono-Drive sprung hub assembly in a fully modular design. Each diaphragm spring undergoes a four-stage heat treatment to provide consistent light pedal feel. Puck-style ceramic friction plates offer high friction coefficient, superior heat capacity, and long clutch life. Torque is uniformly transferred to the Mono-Drive sprung hub assembly, which extends input shaft life and reduces driveline shock from torsional vibration. The lightweight, sprung design allows quicker shifts and reliable operation. This kit includes a CNC-machined and 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 are available separately.

Specs

• Torque Capacity: 1120 ft/lbs (214% over OE)
• Disc Material: Ceramic
• Disc Diameter: 8.8 in / 225 mm
• Input Shaft Diameter: 1 in
• Pressure Plate Type: Xtreme
• Product Weight: 28.1 lbs
• SFI Certified: 1.2

Performance Characteristics

• Feel: Predictable aggressive engagement, light pedal effort, quick shifting, possible start-off judder, OE to mild transmission gear noise
• Life: Forged aluminum cover, Mono-drive hub, exclusive diaphragm, premium friction materials, and hardened wear points ensure long-lasting performance under demanding conditions
• Quality: Engineered for maximum performance and heat tolerance with robust design, premium materials, and tight tolerances
• Recommended Use: Drag, Road, or Rally Racing
• ACT Difference: Ultra-durable, customer-serviceable, high torque capacity twin disc clutch. 100% clamp load tested, dynamically balanced, and SFI certified