Spec Clutch SF334 Stage 4 Performance Clutch Kit - 3/4/6-Puck Carbon Semi-Metallic

The SPEC SF334 Stage 4 Clutch Kit is a race-grade clutch solution engineered for heavily modified, high-output engines where maximum power transfer, instantaneous engagement, and reduced rotating mass are the priority. As SPEC's top-tier single-disc offering, the Stage 4 steps up from the Stage 3 by eliminating the sprung hub in favor of a solid, high-torque rigid hub design built to withstand the demands of competitive motorsports.

Solid Hub Construction: The Stage 4 features a solid 8-rivet hub with a heat-treated assembly for superior strength and durability under extreme loads. This rigid hub design maximizes torque transfer but results in harsher engagement characteristics — making this kit best suited for dedicated race or track vehicles rather than daily street use. The 6-puck configuration offers the most manageable engagement of the available options, though street use is still not recommended due to the rigid hub.

Available Puck Configurations:

• 3-Puck: Lightest rotating assembly — ideal for maximum RPM response and weight reduction
• 4-Puck: A balanced compromise between weight savings and engagement smoothness
• 6-Puck: Smoothest engagement of the three options; most manageable for occasional road use

Key Features:

• High-clamp performance pressure plate for increased clamping force
• Carbon semi-metallic friction material for aggressive grip and high heat tolerance
• Solid 8-rivet, heat-treated hub and disc assembly for maximum torque capacity
• 9.500 in. (241 mm) disc diameter
• 23-spline input shaft, 1.031 in. shaft diameter
• Bearing and tool kit included
• Flywheel not included — sold separately

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

SPEC Clutch designs and manufactures all of its clutch kits and flywheels in-house at their facility in Bessemer, Alabama, maintaining strict tolerances throughout the production process. Every SPEC clutch kit is SFI approved, making the SF334 a trusted choice for sanctioned racing events and serious performance builds.