Wilwood Right Forged Superlite Internal 4 Caliper, 1.25-Inch Rotor Width / 5.18-Sq-In Area

The right-hand wide-rotor FSLI4 has differential 1.88/1.75-inch stainless bores. It provides 5.18 square inches of effective area and a nominal 1.25-inch rotor-width channel in a forged anodized housing. This component comes from Wilwood Engineering, established in 1977 by Bill Wood and based in Camarillo, California. Its disc brake design and manufacturing work includes calipers, brake rotors, master cylinders, valves, fittings and brake lines for motorsport, street-performance and specialized systems.

Technical Details

• Manufacturer part number: 120-11329. Component: Forged Superlite Internal 4 caliper.
• Supply: one brake caliper, not a complete axle brake kit. Match the mating rotor, pads, bracket and connection hardware to the installation.
• Bracket interface: 3.50-inch lug centers with 0.45-inch holes. Specified mount height: 2.85 inches; orientation: right hand.
• Pad fit is type 7420. Match the pad dimensions and compound to the rotor and intended braking conditions.
• Construction and surface: forged aluminum housing finished in Type III anodize.
• Hydraulic inlet thread: 1/8-27 NPT. Use a fitting with the correct thread and sealing seat.
• Caliper weight: approximately 5.2 lb.
• Nominal rotor width 1.25 inch; compatible outside diameter from 11.75 through 13.06 inches. Specified rotor-width limits: 1.19–1.38 inch.
• Piston dust boots: not fitted.
• Bore configuration 1.88/1.75 inches across 4 pistons; piston material: stainless steel. Hydraulic effective area: 5.18 square inches.

Fitment & Compatibility

Match both the right-hand piston arrangement and wider rotor offset. The 3.50-inch lugs do not establish interchangeability with another Superlite width or bore combination.

For a replacement or custom installation, send PMB Performance the brake dimensions and existing component identification. Our 20+ years of experience can help narrow down the correct combination.