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

The Wilwood Forged Narrow Superlite 4R (FNSL4R) radial mount brake caliper represents the latest evolution in high-performance braking technology. Engineered for extreme environments and demanding applications, this caliper combines lightweight construction with exceptional stopping power and precise disc alignment through its dual-plane radial mounting design.

Advanced Forged Construction:

Starting at just 4.9 pounds, each FNSL4R caliper body is stress-flow forged from premium grade aluminum alloy billets. This specialized forging process realigns the metal's internal grain structure to flow within the contour of the caliper body, eliminating the stresses and grain interruptions that occur when machining straight billet blocks. The result is the strongest possible aluminum caliper body, validated through computer-generated solid modeling and FEA stress analysis.

Key Features:

• Radial mounting configuration provides two planes of adjustment for accurate disc alignment
• One-piece stainless steel pistons with slow heat transfer properties and superior corrosion resistance
• Available in multiple piston bore sizes for front or rear brake applications
• Optional Thermlock piston upgrade creates thermal barrier to reduce heat transfer to seals and fluid
• SRS (Stainless Rotor Saver) bridge plates eliminate pad gouging and extend caliper life
• Spring-loaded SRS plates prevent pad rattle and dampen vibrations that cause brake squeal
• Two-piece bleed screws on each end with internal fluid crossovers protect against track debris damage
• High-temperature square-faced bore seals maximize sealing area and control piston retraction

Performance Benefits:

The FNSL4R delivers big brake performance across a broad range of racing and high-performance street applications. Compatible with the full range of Wilwood pad compounds, allowing precise tuning of brake response and heat management for any competition or sports driving scenario. The caliper's thermal management features reduce heat-induced pedal fade and extend component service life.