Wilwood 120-14438 FNSL4R - Dust Seal Universal Radial Mount Caliper 4 Pistons Black

Forged Narrow Superlite 4 Dust Seal Radial Mount

The Forged Narrow Superlite 4R Dust Seal (FNSL4R-DS) is our newest version for the venerable Superlite caliper series adds the versatility and convenience of radial mounting to this widely popular caliper group. Radial mounting simplifies adaptation and provides two planes of adjustment for accurate alignment over the disc. The addition of Wilwood’s exclusive wiper dust seal allows these calipers to be used in areas that may mandate environmental sealing. These calipers integrate "Big Brake" style with Wilwood's latest technology to generate big stopping power in extreme environments over a broad range of vehicle applications.

The key to the superior performance of the FNSL4R-DS comes from the extremely durable and efficient body design. Starting at 4.9 pounds it is the product of computer generated solid modeling and FEA stress analysis technology. The most noteworthy feature of this new caliper design is the forging. Each body is stress-flow forged from premium grade aluminum alloy billets. Stress-flow forging re-aligns the metal's internal grain structure to flow within the contour of the caliper body. This process eliminates the stresses and interruptions to the internal grain structure that occur when machining a straight block billet. Simply stated, there is no better way to build a stronger aluminum caliper body.

A unique six-piston differential bore configuration provides balanced loading for even pad wear in sustained high heat environments. The standard FNSL4R-DS calipers feature one-piece stainless steel pistons. Stainless is used for its slow heat transfer properties and high resistance to corrosion. Calipers can be upgraded with Wilwood's exclusive Thermlock pistons. This multi-part piston design creates a highly efficient thermal barrier to further reduce heat transfer from the pads to caliper body, seals, and fluid. Cooler temperatures translate to longer service life and less chance for heat induced pedal fade.