AP Racing Radi-CAL Brake Kit: Motorsport Braking, Street Legal

The AP Racing Radi-CAL Brake Kit is a radial-mount monobloc caliper system developed directly from AP Racing's motorsport programs, paired with two-piece J-hook rotors, high-temperature brake pads, and braided stainless brake lines.

Unlike many performance kits that adapt street-oriented calipers for harder use, the Radi-CAL design starts from a race caliper platform and is packaged for street and track duty, with a monobloc body that eliminates the bridge-bolt flex found in two-piece calipers.

Standard factory calipers, and even many aftermarket two-piece designs, can flex slightly under hard braking loads. This flex translates into a softer, less precise pedal feel and can allow uneven pad wear over time.

A monobloc caliper body machined from a single piece of aluminum resists this flex far more effectively, while the radial mounting design keeps the caliper properly aligned with the rotor across a wider range of rotor sizes and thicknesses. The result is a noticeably firmer pedal and more consistent bite, lap after lap.

Compared to a factory or entry-level aftermarket brake system, the AP Racing Radi-CAL kit delivers a dramatically firmer pedal, stronger initial bite, and far greater resistance to fade during repeated hard stops. Two-piece J-hook rotors also improve heat dissipation and self-cleaning during heavy track use, reducing pad deposit buildup.

Installing an AP Racing Radi-CAL kit requires removing the factory calipers, brackets, and rotors, then fitting the new radial-mount brackets, calipers, and two-piece rotor assemblies. Brake lines must be replaced with the supplied braided lines, and the entire system needs a full fluid bleed afterward.

Because bracket offsets are wheel-fitment specific, it's worth confirming wheel clearance before installation, since the larger calipers and rotors may require spacers or different wheels on some setups.

Inspect pads, rotors, and caliper pistons regularly, especially after track use, since higher clamping forces can accelerate pad wear. Brake fluid should be replaced on the manufacturer's recommended interval, and braided lines should be checked periodically for wear at the fittings.