Wilwood Superlite FSL4R/ST 4-Piston Caliper with Thermlock® Pistons

Wilwood Superlite FSL4R/ST 4-Piston Caliper with Thermlock® Pistons Wilwood Superlite FSL4R/ST 4-piston calipers deliver race-proven stopping power, reduced weight, and superior thermal management for competitive motorsports and high-performance street use. Built to resist fade and extend pad life, these calipers blend advanced piston geometry with optional Thermlock® pistons for consistent performance under extreme heat. Key Features Differential bore pistons — Optimized piston sizing reduces pad taper and evens wear by compensating for mechanical load and temperature differences across the pad face. Thermlock® piston option (ST) — Proprietary thermal barrier pistons reduce heat transfer to caliper, fluid, and seals by up to 25% versus standard stainless pistons for improved brake feel and longevity. Type III hard anodize finish — Durable, corrosion-resistant coating engineered for harsh racing and off-road environments. Lightweight Superlite construction — High-strength design minimizes unsprung mass for better handling and quicker response. Versatile applications — Ideal for dirt and asphalt oval racing, rally, road course, and aggressive street performance where sustained braking is demanded. Engineered for thermal stability and hydraulic integrity, the FSL4R/ST maintains pad contact consistency and reduces maintenance intervals. Choose the Thermlock® ST variant for maximum heat protection and more repeatable laps under race conditions.