GP320 Caliper - 120-10715

The Wilwood GP 320 billet four piston caliper is a compact, high efficiency performer. Weighing just 1.70 pounds, it was purpose built as an upgrade with increased pad size over two piston calipers on lightweight open wheeled racecars. The GP 320 is also well suited for racing applications including karts, motorcycles, mini-sprints, and formula sports racers. The GP 320 bridge configuration will accommodate rotors between .75 in and .81 in thick, with overall diameters between 9.00 in and 11.50 in . Caliper is full CNC detail machined from premium alloy billet. FEA structural analysis technology was employed to develop a design that minimizes weight and maximizes rigidity against deflection. Full width bridges are reinforced with four, high strength steel cross bridge bolts. The cross bridge bolts are coated for corrosion resistance and provide added resistance to deflection and body separation under high loads. Internal fluid ports with a single outboard bleeder provide quick and effective evacuation of gasses and spent fluid. Clamping force is generated by four, 1.25 in diameter, stainless steel pistons. The clamping force is spread evenly over the length of the pad to minimize backing plate deflection and promote balanced pad wear. The overall piston bore area provides an increase in clamping force over similar range two piston calipers. Stainless steel is used to resist corrosion and retard the heat transfer from the brake pad to the caliper body, seals, and fluid. The GP 320 uses Wilwood type 6211 brake pads. The pads measure .44 in (11,2mm) thick with an overall length of 2.74 in ( 69,6mm). This represents nearly a 50% increase in pad area over some of the popular two piston calipers used on similar applications. The 6211 pad is available in many different compounds from street to high temperature race uses which provide predictable engagement, high friction, long wear, and extreme high temperature fade resistance in the harshest conditions. Other Wilwood performance enhancements include high temperature square faced bore seals that provide a wide sealing area with positive piston retraction on release. Quick-Clip retention pins provide easy access for pad service without caliper removal. The calipers are finished in Type III hard anodizing for protection against corrosion and the elements.