AP RACING BY ESSEX BIG BRAKE KITS

About AP Racing by Essex

Essex Parts Services has been at the forefront of high-performance braking since 1992. Founded by Michael Gue in Essex, Connecticut as an offshoot of his racing team that competed in SCCA and IMSA events, the company evolved into one of North America's premier suppliers of motorsport braking components. Now based in Charlotte, North Carolina, Essex is the exclusive North American designer and assembler of AP Racing big brake kits for street and track applications. Every kit sold through Function Factory Performance is designed, assembled, and quality-checked by Essex's team using genuine AP Racing components.

AP Racing needs no introduction in the motorsport world. With countless wins in Formula 1, NASCAR Sprint Cup, ALMS, DTM, and WRC, AP Racing components are the choice of champions at every level of professional racing. Essex brings this race-proven technology to enthusiasts through meticulously designed brake kits that deliver genuine motorsport performance for your road or track car.

What Is AP Racing Radi-CAL Technology?

AP Racing's patented Radi-CAL caliper design represents the biggest leap in brake caliper engineering in decades. Using advanced CAD modeling and Finite Element Analysis (FEA), material is redistributed based on dynamic loads rather than static ones — resulting in an asymmetrical design that looks radically different from traditional box-shaped calipers. The results speak for themselves:

• 30%+ increase in both static and dynamic stiffness
• 33% reduction in deflection versus leading competitors
• Significantly lighter — the CP9660 weighs just 6.13 lbs (2.78 kg), the CP9668 just 6.83 lbs (3.1 kg)
• Superior thermal management with optimized airflow and stainless steel domed pistons that reject heat
• More even pad wear and longer caliper service life

Radi-CAL technology debuted in NASCAR in 2007 — Tony Stewart won at Watkins Glen using the first Radi-CAL calipers. Today, the technology is standard across Formula 1, Sprint Cup, and countless professional road racing series worldwide. Essex brings this same technology to street and club racing applications through their Radi-CAL Competition and Road brake kits.

AP Racing by Essex Brake Kit Types

Competition Brake Kits (Track/Race)

Designed for dedicated track cars and serious track day enthusiasts. Competition kits feature anodized calipers with stainless steel pistons (no dust boots) for maximum heat resistance, anti-knockback piston springs to prevent pad retraction under heavy cornering loads, and high vane count two-piece floating discs optimized for weight reduction. Pads and fluid are not included — track drivers typically swap between different compounds depending on conditions. Available in both standard and Radi-CAL caliper configurations.

Radi-CAL Road Brake Kits (Street/Dual-Purpose)

Built for street-driven cars that see occasional track use. Road kits use painted calipers (red, black, or silver) with aluminum pistons and dust boots to protect against road debris, salt, and moisture. Available with one-piece or two-piece disc options and includes sport brake pads and fluid. These kits deliver a massive upgrade in braking performance while maintaining daily-driver reliability and the aesthetics to fill your 18", 19", or 20" wheels.

ENP (Electroless Nickel Plating) Finish

Select AP Racing by Essex kits are available in an ENP (Electroless Nickel Plating) finish — a hard, corrosion-resistant nickel coating applied to the caliper body. ENP provides superior protection against the elements compared to anodizing, making it ideal for cars that split time between track days and street driving. The distinctive silver-nickel finish also gives a clean, factory-quality appearance behind the wheel.

Vehicle Applications at FFP

Why Buy AP Racing by Essex from FFP

Function Factory Performance is an authorized AP Racing by Essex dealer — every kit we sell comes factory-direct from Essex Parts Services with full manufacturer warranty and support. But what sets us apart is expert installation. Our Thousand Oaks, California shop has hands-on experience installing Essex big brake kits on Mustangs, BMWs, and McLarens. Brake kit installation is one of the most precision-critical jobs on any car — caliper alignment, rotor runout, line routing, and pad bedding all need to be done exactly right to get the performance these kits are designed to deliver. When you buy from FFP, you're not just getting a box of parts — you're getting access to a team that knows these kits inside and out. Call 805-206-2523 to discuss your build.

AP Racing Caliper Quick Reference

Frequently Asked Questions