ACT Mod-Twin 225 Heavy Duty Sprung Race Twin Disc Clutch Kit 2004-2021 STI

The Mod-Twin 225 HD Sprung Race Kit is engineered for high-powered AWD vehicles, providing aggressive launches with smoother shifting. This modular twin-disc design combines twice the ceramic friction surfaces with an ultra-durable Mono-Drive sprung hub assembly. Each diaphragm spring undergoes a four-stage heat treatment for consistent light pedal feel. Puck-style ceramic friction plates deliver a high friction coefficient, superior heat capacity, and long clutch life. Torque is evenly transferred through the Mono-Drive sprung hub assembly, which extends input shaft life and reduces driveline shock from torsional vibration. The kit includes 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 required). Mod-Twin clutches are fully rebuildable, with most components available separately.

Specs

• Torque Capacity: 895 ft/lbs (152% over OE)
• Disc Material: Ceramic
• Disc Diameter: 8.8 in / 225 mm
• Input Shaft Diameter: 1 in
• Pressure Plate Type: Heavy Duty
• Product Weight: 28.1 lbs
• SFI: 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: Maximum performance and high heat tolerance through robust design, strategic features, select materials, and precise tolerances
• Recommended Use: Drag, Road, or Rally Racing
• ACT Difference: Ultra-durable, customer-serviceable twin disc clutch, 100% clamp load tested, dynamically balanced, and SFI certified