Spec Clutch SM381 Stage Performance Clutch Kit - 1

The Spec Clutch SM381 Stage 1 Clutch Kit is a high-performance clutch solution built for drivers who demand more than a stock replacement without sacrificing daily driveability. Featuring an integrally molded carbon Kevlar-based, high-performance organic friction lining, this clutch delivers smooth, predictable engagement and exceptional service life. The lining is bonded to a steel backing plate for added strength under high clamp loads and elevated operating temperatures.

The disc hub is double-sprung with spring cover reliefs for torsional flexibility during engagement, while all hub components are heat-treated for long-term strength and durability. With a 9.500 in. (241mm) disc diameter, a 1.031 in. input shaft, and 23-spline count, the SM381 is a precisely engineered fit for its application. Designed and hand-built in the U.S.A., every SPEC clutch kit meets rigorous quality standards before leaving the factory.

Key Features:

• Carbon Kevlar-based, high-performance organic friction lining for smooth engagement and long life
• Steel-backed, multi-compound woven organic disc material for strength under load
• High-clamp performance pressure plate for improved torque transfer
• Double-sprung hub with spring cover reliefs for flexibility and reduced driveline shock
• Heat-treated hub components for enhanced strength and durability
• 9.500 in. (241mm) disc diameter | 1.031 in. input shaft | 23-spline
• Includes high-clamp pressure plate, clutch disc, release bearing, and alignment tool

Recommended Driving Applications: Street, Drag, Drift, Road Race, Rallye, Pulling, Autocross

The SPEC SM381 Stage 1 is an ideal upgrade for bolt-on naturally aspirated and mildly modified forced induction engines, providing stock-like pedal feel with a significant jump in holding power, wear life, and overall clutch quality.