SPEC SC86S High Carbon Billet Steel Flywheel SFI Certified

The SPEC SC86S is a high carbon billet steel flywheel precision-engineered for high-performance street and racing applications. SPEC flywheels are CNC machined to an industry-leading .001 inch tolerance — ten times tighter than the industry-standard .010 — delivering a perfectly flat clutch disc bedding surface and exceptional rotational balance. Every SPEC flywheel carries SFI certification, making them a trusted choice in competitive environments where safety and precision are non-negotiable.

The flywheel is the single most critical component in ensuring optimum clutch performance and longevity. The SC86S fulfills the three essential roles of a performance flywheel:

• Friction Surface: Provides a consistent, friction-enhancing contact surface for reliable clutch disc engagement and holding power
• Inertia Management: Flywheel weight directly controls the ratio of power to acceleration, influencing drivability and response across different gear ratios, tire types, and power outputs
• True Rotational Balance: Engineered to eliminate dimensional runout at high RPM, preventing engine-damaging vibrations and ensuring smooth, consistent engine revolutions

The SC86S is constructed from high carbon billet steel, offering a medium-weight inertia option that is well-suited to street performance and a wide range of racing disciplines. Steel flywheels retain RPM more effectively during gear changes compared to aluminum alternatives, making them a practical choice for street-driven vehicles that also see track time. SPEC invests extensively in research and development to optimize flywheel dimensions and moment of inertia (MOI) for specific driving environments, ensuring the SC86S delivers measurable performance gains for your application.