Wilwood Forged Superlite Internal Caliper

The Superlite caliper series is the benchmark in short track, late model, modified and open wheel competition. It also enjoys prominence in a variety of road-race, off-road, rally and sport driving applications. The new FSLI model series is the latest innovation to this Superlite family of calipers. It has been redesigned with internal fluid ports that eliminate the external fluid cross-over tubes, along with any potential problems that could arise from a damaged tube. The transfer tube has been replaced with two additional bleed screw assemblies which allows this group of symmetrical piston bore models to be mounted either right or left in a leading or trailing position.

The most noteworthy feature of all of the FSL caliper models is the exceptional strength and reduced weight of the forging. With assembled weights just at 4.4 pounds, the FSL body design in itself is a product of computer generated solid modeling and stress analysis technology. Each caliper features closed end bridges with a radial transition down to the main body and piston bore housings. The elimination of machined steps and sharp shoulders in this critical area provides a measurable increase in overall body strength and resistance to deflection under load.

Every FSL body is stress-flow forged from a premium grade aluminum alloy billet. Stress-flow forging realigns 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.

FSL calipers are assembled with high strength steel main bridge bolts in tension and then supplemented with center bridge bolts to provide maximum resistance and strength against deflection and body separation under load. The center bridge support also provides positive pad retention with quick access when it’s time for service. Clamping force, structural deflection, and volume displacement tests have proven the superior strength and efficiency of the FSLI. Simply stated, there is no better way to build a stronger or more efficient one or two-piece aluminum caliper body at equal or lower weight.

FSL calipers feature all of Wilwood’s latest refinements and proven performance features including replaceable SRS stainless steel bridge plates. SRS plates extend caliper life by preventing wear at the bridge abutments otherwise caused by pad edge gouging. Spring tension in the SRS plates also eliminates pad rattle and helps to dampen the vibration harmonics that can contribute to squeal under braking. Other standard Wilwood features include high-temperature, square faced o-ring seals for positive sealing, controlled piston retraction, and long service life in high heat conditions. Machined stainless steel pistons are used to resist corrosion, retard heat transfer, and eliminate backside deflection under pressure. Two-piece bleed screw assemblies provide long, reliable service life and are easily replaced if necessary.