Wilwood GN4R-ST Front Race Brake Kit for Ford Mustang (2005–2014), 13-Inch Dynamic Lug Drive GT Rotors and Braided Hoses

Ford Mustang front race brakes combine GN4R-ST calipers, Thermlock pistons and 13-inch GT rotors. Check wheel fit; racing pads require operating heat. Bill Wood founded Wilwood Engineering in 1977 in Camarillo, California, where the company is based. Wilwood designs and manufactures disc brake systems, producing brake rotors, calipers, master cylinders, fittings, valves and brake lines for motorsport, street-performance and specialized applications. Individual parts are selected to meet the requirements of the complete braking system.

Technical Details

• Manufacturer part number: 140-16666
• Kit function: Front Brake Kits - Road Race; front position
• Service calipers: 4-piston GN4R; Type III Anodize
• Caliper mounting: Radial; piston material: Thermlock
• Rotor package: 13.00 × 1.25 inches; Spec-37 Iron; vented; GT Slotted
• Supplied service-pad compound: BP-35
• Hydraulic inlet: 1/8-27 NPT
• Rotor / hub bolt-circle specification: 5 x 4.5 in; 5 x 114.3 mm
• Nominal wheel diameter reference: 17 in; verify the complete clearance drawing
• Hydraulic flexlines: Included; 220-9111 (18.00 in)
• Included installation items: mounting hardware
• Not supplied: spindles, wheel hubs, master cylinder, brake booster
• Quantity: Sold as a kit.

Fitment & Compatibility

The GN4R-ST kit is intended for four-piston road-race applications on the listed 2005–2014 Mustang configurations. Compare the full GT, Boss 302, Bullitt and Shelby rows and their factory brake conditions in the table below. Dynamic lug-drive GT rotors and Thermlock pistons are paired with BP-35 pads; extended cold operation causes premature pad and rotor wear. The 18-inch braided flexlines are included. Check DS-1482 against the actual wheel profile: catalog wheel-size statements do not replace a complete clearance check.

Wilwood product specifications · Installation instructions

For a race-brake fitment check backed by more than 20 years of parts experience, send PMB Performance the hub, spindle, wheel and complete brake-system details. Selection depends on the actual competition installation.

Manufacturer warning — brake pads only: WARNING: Cancer and Reproductive Harm. www.P65Warnings.ca.gov.