Spec Clutch SC664 Stage 4 Performance Clutch Kit - Carbon Semi-Metallic

The Spec Clutch SC664 Stage 4 Clutch Kit is a high-performance, solid-hub clutch system engineered for heavily modified, high-output applications demanding maximum power transfer and instantaneous engagement. This is a race-focused upgrade built for drivers who prioritize performance over daily drivability.

The SC664 is a solid-hub evolution of the Stage 3 design. The 8-rivet solid hub eliminates the spring dampening found in street clutches, and the entire assembly is heat-treated for superior strength and long-term durability under extreme conditions. It is capable of handling up to 809 lb-ft of torque at the flywheel.

Available Puck Configurations:

• 3-Puck: Lightest option — ideal for maximum weight reduction in racing applications
• 4-Puck: Balanced compromise between weight savings and engagement smoothness
• 6-Puck: Smoothest engagement of the three; marginally street-drivable, though the rigid hub makes it unsuitable for comfortable everyday use

Kit Includes:

• High-clamp performance pressure plate
• Carbon semi-metallic friction disc (3, 4, or 6 puck — specify at time of order)
• High-torque solid hub and carrier assembly
• Bearing and installation tool kit

Recommended Driving Applications: Drag Racing, Road Racing, Drifting, Rally, Pulling, Circle Track

Break-In Requirement: A minimum of 450 miles of primarily city/stop-and-go driving is required before full-throttle engagement, drag launching, or speed shifting. Failure to complete the break-in process may hinder clutch performance and will void the warranty.