AP Racing Radi-CAL ENP Competition Front Kit 355mm - Subaru WRX STI

The AP Racing by Essex Radi-CAL ENP Competition Brake Kit gives the Subaru WRX and WRX STI a front brake system made for track work and rally-bred abuse. It combines AP Racing CP9660 Radi-CAL Pro5000R six-piston calipers in electroless nickel plating with 355 x 32mm, 72-vane J Hook discs, replacing the factory four-piston brakes on Impreza WRX and STI models from 2002 and the VA-chassis WRX and STI through 2021.

Why upgrade

Turbocharged all-wheel-drive Subarus carry a lot of weight over the front axle, and the stock brakes fade quickly under repeated hard stops. This kit eliminates about 10 pounds of unsprung weight from the nose: each caliper is 6.2 pounds against 8.2 for the OEM STI unit, and each disc 17.6 pounds against 21.8, while disc diameter grows from 326mm to 355mm. Piston sizing integrates with the factory master cylinder and ABS.

Caliper and disc construction

The CP9660 is a computer-optimized, asymmetric Radi-CAL body that is stiff along the load paths and trimmed of weight elsewhere. Its ENP coating is resistant to wear and deterioration at high temperature and cleans easily after a dusty event. Stainless steel pistons, anti-knockback springs and high-temperature seals keep the pedal firm, and pads change without unbolting the caliper. The CP7177 discs float on 6061 hard anodized aluminum hats.

Features

• AP Racing CP9660 Radi-CAL Pro5000R six-piston calipers in ENP finish
• 355 x 32mm, 72-vane J Hook discs on floating hats
• About 10 lb lighter than the factory front brakes
• Larger, cooler running disc than the 326mm OEM part
• Works with the OEM rear brakes

What's Included

• One pair AP Racing CP9660 Radi-CAL Pro5000R racing calipers in ENP (Electroless Nickel Plated) finish
• One pair 355x32mm AP Racing CP7177, 72 vane, J Hook racing discs, with fully floating 6061 hard anodized aluminum hats and attachment hardware
• One pair caliper mounting brackets and hardware
• One pair Spiegler Stainless Steel Brake Lines with abrasion resistant coating
• Detailed installation instructions

Brake pads are not included.

Specifications

Video

Fitment notes

Covers the US WRX and WRX STI models below. The confirmed wheel is Volk Racing TE37 SL 18 x 9 ET45 without a spacer; factory wheels have not been confirmed, so check your wheels with the wheel fitment template before ordering. Call us to confirm your hub before ordering.

Fitment