Billet Superlite 4R Radial Mount-ST

The Billet SL4R 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 key to the superior performance of the SL4R comes from the extremely durable and efficient body design. Starting at 4.84 pounds it is the product of computer generated solid modeling and FEA stress analysis technology. Full length stiffening ribs and a reinforced radial transition from the piston bore housings to the closed end bridges has produced the strongest SL caliper bodies ever built.

When compared to open bridge calipers that use tube or stand spacers between the body halves, the closed end bridge design is measurably stronger with less separation or deflection under load. Additional strength and resistance to deflection comes from the four high-strength steel end bridge bolts. A fifth center bridge bolt provides even more overall strength and easy access to the pads without the need to remove the caliper from the mount. Calipers can be had in 4-piston differential bore configurations provide balanced loading for even pad wear in sustained high heat environments. Also available are non-differential piston 'square-bore" units targeted for racing classes that require the OEM master cylinder to be used.

The standard SL4R calipers feature one-piece stainless steel pistons. Stainless is used for its slow heat transfer properties and high resistance to corrosion. The SL4R/ST models feature 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. In addition, each SL4R is equipped with SRS bridge plates. SRS plates eliminate all bridge wear caused by pad gouging and extend the service life of the caliper. The spring-loaded action of the SRS plates also eliminates pad rattle and dampens the harmonic vibrations that contribute to pad squeal.