Spec Clutch SZ385 Stage 5 Clutch Kit - Full-Metallic Sintered Iron Disc

The Spec Clutch SZ385 Stage 5 Clutch Kit is engineered for the most demanding high-performance and motorsport applications. Built around a full-metallic sintered iron disc, this kit delivers the highest possible friction coefficient available in the SPEC clutch lineup — making it the top choice for heavily modified drag race engines and high-load pulling applications.

Unlike sprung hub designs, the Stage 5 uses a rigid, unsprung disc assembly with a solid 12-rivet hub that is heat-treated for maximum strength and durability. Because there are no springs to dampen driveline shock, this clutch provides extremely aggressive, direct engagement — ideal for race environments where maximum torque transfer and quick, consistent launches are the priority.

Kit Contents:

• High-clamp pressure plate (adjustability available on select applications)
• Full-metallic rigid iron disc assembly
• Release bearing
• Installation tool kit

Key Features:

• Full-metallic friction material for the highest available friction coefficient
• High-clamp pressure plate for maximum torque clamping force
• Solid 12-rivet unsprung hub — heat-treated for strength and durability
• Progressive torque-induced engagement capability
• Suitable for slipper clutch applications
• Best for drag racing and pulling competitions

Important Note: This clutch is not street-friendly due to its harsh engagement characteristics. The unsprung hub design does not absorb drivetrain vibration, which can result in clutch chatter under normal driving conditions. This kit is intended for dedicated race and competition use. For best results, consult a SPEC technical representative with details about your specific build and application before ordering, as custom configurations are available.