Spec Clutch SN504 Stage 4 Carbon Clutch Kit

The SPEC SN504 Stage 4 Clutch Kit is a competition-grade clutch system engineered for heavily modified engines where maximum torque transfer, instantaneous engagement, and reduced rotating mass are critical. This is a race-focused, track-only solution — not intended for street driving due to its aggressive engagement characteristics.

Key Features:

• Solid 8-Rivet Hub: A solid hub design (an advancement over the sprung Stage 3 hub) with eight rivets and heat-treated construction for exceptional strength and durability under extreme loads
• High Clamp Pressure Plate: Delivers aggressive, precise clutch engagement suited for high-output applications
• Carbon Semi-Metallic Friction Disc: Available in 3, 4, or 6-puck configurations — the 3-puck minimizes rotational weight, the 4-puck balances performance with engagement feel, and the 6-puck offers slightly smoother engagement among the puck options
• SFI Approved: Meets SFI standards for motorsport competition use
• Complete Kit: Includes high clamp pressure plate, carbon semi-metallic puck disc, high torque rigid hub and carrier assembly, release bearing, and installation tool kit

Intended Use:

• Drag Racing
• Drifting
• Road Racing
• Rally
• Circle Track
• Pulling

Important Note: The Stage 4 is not street-friendly. Its rigid hub and aggressive clamp load produce harsh engagement that is best suited for dedicated competition vehicles. For applications requiring street drivability, consider the SPEC Stage 3 or lower.