Wilwood 120-13576 FSL4R/ST Forged Superlite 4-Piston Rear Brake Caliper

The Wilwood FSL4R/ST forged superlite caliper delivers professional-grade braking performance with advanced differential bore piston technology and optional Thermlock® heat-resistant pistons. Engineered for sustained hard braking in oval track racing, off-road, rally, and road course applications, this caliper combines exceptional strength with lightweight construction.

Key Features:

• Differential bore pistons provide optimized pad wear and consistent braking performance
• Internal fluid ports eliminate external crossover tubes for cleaner installation and reduced failure points
• Dual bleed screw assemblies allow left or right hand orientation without leading/trailing configuration requirements
• Type III hard anodized finish delivers superior wear and corrosion resistance
• Stress-flow forged from premium grade aluminum alloy billet for maximum strength-to-weight ratio
• Closed end bridges with radial transitions reduce stress concentrations and body deflection under load
• Lightweight design at just 4.4 pounds assembled weight
• Computer-generated solid modeling and stress analysis optimized body design

The FSL4R represents a complete redesign of Wilwood's popular four-piston rear caliper platform, incorporating lessons learned from professional racing applications. The elimination of external fluid tubes simplifies installation and reduces potential leak points, while the advanced forging design provides measurable improvements in rigidity and thermal management. Ideal for dirt and asphalt oval track racing, as well as demanding road course and off-road competition use.