Spec Clutch SM804 Stage 4 Racing Clutch Kit - Carbon Semi-Metallic Puck Disc

The Spec Clutch SM804 Stage 4 Clutch Kit is a high-performance, race-focused clutch system engineered for heavily modified engines demanding maximum torque transfer. Rated for up to 525 ft/lbs of torque, this kit delivers instantaneous engagement and reduced rotating mass — making it a top choice for serious motorsport applications including drag racing, road racing, drifting, rallye, pulling, and circle track competition.

The Stage 4 is a solid hub evolution of the Stage 3 design. The rigid, solid 8-rivet hub eliminates the compliance found in sprung-hub clutches, providing immediate, aggressive engagement ideal for race-only use. The entire hub assembly is heat-treated for maximum strength and long-term durability under extreme load.

Key Features:

• SFI Approved — certified for competitive racing applications
• High-clamp pressure plate for maximum clamping force on heavily modified powerplants
• Carbon semi-metallic friction disc — available in 3, 4, or 6-puck configurations
• Solid 8-rivet rigid hub — heat-treated for strength and durability
• 3-puck: lightest weight option for maximum RPM response
• 4-puck: balanced compromise between weight and engagement smoothness
• 6-puck: smoothest engagement of the three configurations
• Includes high-torque carrier assembly, release bearing, and installation tool kit

Intended Use: Drag, Drift, Road Race, Rallye, Pulling, Circle Track

Note: The Stage 4 is a race-only clutch. Due to its rigid hub design, it is not street-friendly and produces harsh engagement characteristics not suitable for daily driving. The solid hub eliminates the spring dampening present in street-oriented clutches, which is a deliberate design choice to maximize torque holding capacity and response.