Spec Clutch SB63ST Super Twin Multi-Disc Clutch Kit ST-Trim with Billet Steel Flywheel

The SPEC SB63ST Super Twin ST-Trim is a high-performance multi-disc clutch and flywheel kit engineered for street and track applications in vehicles producing extreme horsepower and torque — rated to handle between 700 and 1,500 ft-lbs of torque. Despite its race-level capability, the Super Twin delivers near-stock drivability with smooth, quiet operation thanks to its all-billet construction.

The ST-Trim designation uses carbon composite friction discs with a dampened, full-face design that provide aggressive yet controllable engagement across a wide range of performance driving disciplines. The assembly is precision-machined from aircraft-grade aluminum and high-carbon billet steel, milled to industry-leading .001-inch tolerances for perfect balance and consistent actuation.

Key Features:

• Torque capacity: 700–1,500 ft-lbs — ideal for heavily modified street and track builds
• ST-Trim carbon composite full-face dampened dual discs
• All-billet construction — aircraft-grade aluminum and high-carbon billet steel
• Precision-milled to .001-inch tolerances for optimal balance and actuation
• No shimming or setup required — true bolt-in installation
• Maintenance-free operation with a long service life
• Rebuildable by SPEC or the end user; replacement components always available
• Billet steel flywheel and track-spec hardware included
• Suitable for street, drag, drift, road racing, time attack, pulling, and rallye

Each kit ships complete with a billet steel flywheel and track-spec hardware, making installation straightforward without the need for additional shimming or custom setup. The units are fully rebuildable, and SPEC offers rebuild services and replacement components to maximize the long-term value of your investment.