Wilwood 120-14438-BK Forged Narrow Superlite Dust Seal Disc Brake Caliper - 4R

The Wilwood Forged Narrow Superlite 4R Dust Seal (FNSL4R-DS) represents the latest evolution in high-performance brake caliper technology. Featuring exclusive wiper dust seals, this caliper is engineered for extreme environments where environmental sealing is essential, delivering big brake stopping power across a wide range of performance applications.

Advanced Forged Construction:

Weighing just 4.9 pounds, the FNSL4R-DS body is stress-flow forged from premium grade aluminum alloy billets. This specialized forging process re-aligns the metal's internal grain structure to flow within the caliper body contours, eliminating internal stresses and creating a significantly stronger structure than traditional machined billet designs. Computer-generated solid modeling and FEA stress analysis ensure optimal strength-to-weight ratio and durability.

Key Features:

• Six-piston differential bore configuration for balanced pad loading and even wear in high-heat conditions
• One-piece stainless steel pistons with slow heat transfer properties and superior corrosion resistance
• Compatible with optional Thermlock pistons for enhanced thermal barrier protection
• SRS (Stainless Rotor Sleeves) bridge plates eliminate bridge wear from pad gouging and prevent pad rattle
• Integrated wiper dust seals for environmental protection in demanding conditions
• Two-piece bleed screws on each end with internal fluid crossovers for protected fluid routing
• High-temperature square-faced bore seals maximize sealing area and provide controlled piston retraction
• Spring-loaded SRS plates dampen harmonic vibrations to reduce pad squeal

Performance Benefits:

The differential bore design ensures balanced brake pad wear during sustained high-temperature operation. Stainless steel pistons minimize heat transfer to the caliper body, seals, and brake fluid, while the optional Thermlock piston upgrade creates an additional thermal barrier for even cooler operating temperatures. This translates to extended service life, consistent pedal feel, and reduced risk of heat-induced brake fade.

Compatible with the full range of Wilwood pad compounds, allowing precise tuning of brake response and heat range for competition racing, track days, and aggressive street driving applications.