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.
Additional Notes
Two piece bleed screws and dampened fluid tubes are recess mounted to shield them from track debris and other potential damage sources. High temperature, square faced bore seals provide the largest possible sealing area and controlled piston retraction on release. The full range of Wilwood pad compounds is available to match the brake response and heat range of any competition or sports driving application. Certain calipers in this group feature a reduced width outboard body to provide additional clearance between the caliper face and the wheel or hub. These calipers were originally built for use with wide 5 hubs, but have found their way to OE performance "Big Brake" conversions, road racing, and other close fit wheel applications. The caliper bridge radius will clear rotors from 11.75" to 13.06" in overall diameter. Each caliper in this group uses 7420 type 20mm thick pads.
About Wilwood Engineering
Wilwood Engineering designs and manufactures high-performance disc brake systems. Since the company’s inception in 1977 by Bill Wood, we have developed a substantial matrix of brake components and engineering techniques that allow us to quickly and reliably create brake systems for almost any application. Our core ability is the rapid development of custom engineered brake systems using a combination of off-the-shelf and custom components. In addition to designing and manufacturing brakes for all types of competitive motor sports, Wilwood also manufactures brake systems and components for agricultural equipment, industrial applications, utility vehicles, snowmobiles, quads, motorcycles and military vehicles.
With headquarters in Camarillo, California, Wilwood employs approximately 250 people. We have on-shelf stock of more than 300 different brake calipers, 200 rotor designs, 100 master cylinder designs and a wide assortment of brackets, fittings, valves and brake lines. Our off-shelf brake calipers range in size from tiny calipers used on go-carts and light duty industrial equipment, to heavy duty original equipment brakes for the U.S. military Humvee.
Wilwood's engineering department uses the latest computer-aided design and manufacturing techniques in conjunction with finite element analysis, dynamic test and cycle test equipment, to find high-performance and reliability solutions for the most difficult braking tasks. Our extensive inventory of proprietary on-the-shelf components allow us to provide cost-effective solutions for unique brake applications.
Wilwood is ISO 9000 compliant and has extensive experience maintaining quality levels of 100ppm or less for original equipment manufacturers.
