Wilwood 120-14055-Y Forged Narrow Superlite Radial Mount Brake Caliper - 4R

The Wilwood Forged Narrow Superlite 4R (FNSL4R) radial mount disc brake caliper combines race-proven performance with precision engineering for extreme braking applications. Designed for vehicles requiring high-performance stopping power, this caliper features radial mounting that simplifies installation and provides two planes of adjustment for precise alignment over the rotor.

Advanced Construction:

Each caliper body is stress-flow forged from premium-grade aluminum alloy billets, a process that realigns the metal's internal grain structure to flow within the contour of the caliper body. This eliminates internal stresses and grain interruptions that occur with traditional billet machining, creating an exceptionally strong and durable caliper that weighs just 4.9 pounds. The design is optimized through computer-generated solid modeling and FEA stress analysis technology.

Key Features:

• Stress-flow forged aluminum body for maximum strength and minimum weight
• Radial mounting with dual-plane adjustment capability
• One-piece stainless steel pistons with slow heat transfer properties and superior corrosion resistance
• Available in multiple piston bore sizes for front or rear applications
• SRS (Stainless Rotor Sleeves) bridge plates eliminate bridge wear and pad rattle while dampening vibrations
• Two-piece bleed screws on each end with internal fluid crossovers protected from debris
• High-temperature square-faced bore seals for maximum sealing area and controlled piston retraction
• Compatible with full range of Wilwood performance pad compounds
• Optional upgrade to Thermlock multi-part pistons for enhanced thermal barrier performance

The FNSL4R delivers professional-grade braking performance with cooler operating temperatures, extended service life, and resistance to heat-induced brake fade. Ideal for road racing, track days, and high-performance street applications where reliability and stopping power are critical.