Wilwood 120-15734 Powerlite-ST Radial Mount Disc Brake Caliper - 4-Piston

The Wilwood Powerlite-ST is a high-performance four-piston radial mount disc brake caliper engineered for rally, circle track, and off-road competition use. Starting at just 2.5 pounds, it delivers an exceptional strength-to-weight ratio while maintaining durability under sustained high-temperature braking conditions. Wilwood's exclusive Thermlock pistons provide additional thermal insulation, protecting the caliper body and brake fluid from heat transferred through the rotor.

Stress-Flow Forged Construction:

The Powerlite-ST's structural integrity begins at the manufacturing level. Stress-flow forging re-aligns the metal's grain structure to follow the contour of the caliper body — eliminating the internal grain interruptions that result from machining a straight billet block. This is further reinforced by an FEA-optimized radial transition design that removes steps and shoulders between the piston housing and caliper bridges, significantly increasing resistance to deflection and caliper separation under heavy braking loads.

Key Features:

• Four-piston radial mount design — starting weight of 2.5 lbs for maximum unsprung weight reduction
• Thermlock pistons — insulate caliper and fluid from high rotor temperatures
• Stress-flow forged aluminum body — optimized grain structure for superior strength without added weight
• FEA-generated radial transition bridges — enhanced resistance to deflection and caliper separation under load
• 7912-type brake pads with Quick-Clip top-retention retainers — no pad support step required, enabling closer hub mounting on small wheel and rotor applications
• Compatible rotor diameters: 9.45 in (240.0 mm) to 11.75 in (298.5 mm) — fits inside many 13.00 in (330.2 mm) wheel applications
• Quick-Clip pad retainers — allow fast, tool-friendly pad changes without removing the caliper
• SRS stainless steel bridge plates — prevent bridge wear from pad gouging, eliminate pad rattle, and dampen vibration harmonics that cause brake squeal
• Internal fluid passages — no external fluid tubes required for a cleaner, more reliable installation
• Four-corner bleed screws — ensure thorough air evacuation; caliper can be mounted in any of four orientations
• Bracket kits (sold separately) accommodate radial mounting with two planes of adjustment for precise rotor alignment; kits include radial mount bracket, studs, locknuts, and caliper alignment shims

With a full range of compatible 7912-type brake pad compounds available for sport and competition use, the Powerlite-ST is a proven choice for builders and racers who demand lightweight, thermally resilient, and precisely engineered stopping power.