Spec Clutch SC57A Billet Aluminum Flywheel SFI Certified - 1.1

The Spec Clutch SC57A is a billet aircraft-quality aluminum flywheel engineered for high-performance and racing applications. CNC machined to an industry-leading .001-inch tolerance—ten times tighter than the industry standard of .010—this flywheel delivers exceptional dimensional precision, a perfectly flat clutch disc seating surface, and true rotational balance at high RPM. Every SC57A carries SFI 1.1 certification, making it suitable for competitive motorsport environments.

Key Features:

• Billet aircraft-quality aluminum construction for reduced rotating mass
• 14.000-inch diameter with 168-tooth ring gear
• Internal engine balance design
• CNC machined to .001-inch tolerance for a guaranteed flat clutch seating surface and zero harmful runout
• Replaceable steel friction plate specially formulated for optimal clutch bedding and holding power, allowing the flywheel to be rebuilt rather than replaced
• SFI 1.1 certified for use in sanctioned racing competition
• Race bolt kit included
• Designed for use with SPEC single-disc clutch kits and compatible aftermarket LS1/LS6-style single-mass clutch systems — not intended for use with OEM-style clutch designs

Aluminum vs. Steel Flywheel:

Compared to a steel flywheel, the SC57A aluminum unit provides faster engine revving, reduced drivetrain drag, and quicker throttle response by significantly lowering rotating mass. This makes it the preferred choice for track-focused builds where rapid acceleration and crisp gear changes are a priority. The SC57A is engineered and optimized by SPEC's R&D team specifically for its application, accounting for vehicle weight, gear ratios, tire type, power output, and powerband characteristics to deliver the ideal Moment of Inertia (MOI) for maximum performance.

The flywheel's three core functions — providing a consistent friction surface, contributing the correct inertia for the application, and maintaining true dimensional balance at RPM — are all executed at a level of precision that surpasses generic lightweight flywheel alternatives. SPEC flywheels are application-specific, not one-size-fits-all components, and are developed through extensive real-world testing to optimize output for each platform.

Note: This flywheel requires a SPEC single-disc clutch kit for proper installation and operation. It is not compatible with OEM-style clutch assemblies. This application uses a concentric hydraulic slave/bearing assembly rather than a conventional throwout bearing.