AP Racing Radi-CAL Competition Front Kit 355mm - Porsche 981, 718

The AP Racing by Essex Radi-CAL Competition Brake Kit is a front system for the mid-engine Porsche 981 and 718 Boxster and Cayman. It fits every 981 variant except the GT4, along with 718 base, S, T and 2.5-liter GTS models, replacing the factory front brakes with AP Racing CP9661 Radi-CAL Pro5000R six-piston calipers and 355 x 32mm, 72-vane J Hook discs.

Why upgrade

Boxster and Cayman owners who track their cars quickly learn that the factory one-piece discs crack and the pads wear fast. This kit uses a two-piece floating disc that weighs 17.6 pounds against 20.2 pounds for the 981 S part and 21.7 pounds for the 718 S part, saving about 2 pounds over the 981 Cayman S system and 10 pounds over the 718 S system. A major practical gain is that front pads change without removing the caliper, which makes swapping between street and track compounds a quick job in the paddock.

Caliper and disc construction

The CP9661 is a computer-optimized, asymmetric Radi-CAL caliper with a hard anodized finish. Stainless steel pistons insulate the fluid from heat, anti-knockback springs keep the pedal firm, and low-drag seals stand up to sustained track temperatures. Pads are available from all major manufacturers. The CP7177 J Hook discs ride on 6061 hard anodized aluminum hats with fully floating hardware. Pistons are sized for the OEM master cylinder and ABS.

Features

• AP Racing CP9661 Radi-CAL Pro5000R six-piston calipers
• 355 x 32mm, 72-vane J Hook discs on floating aluminum hats
• Saves 2 to 10 lb depending on the car
• Front pads change without removing the caliper
• Works with the OEM rear brakes or a matching AP Racing rear kit

What's Included

• One pair AP Racing CP9661 Radi-CAL Pro5000R racing calipers
• 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

Fits the 981 and 718 Boxster and Cayman models below. Not for the GT4, 718 Spyder or the 4.0-liter GTS. Clears the OEM 19 inch wheel from the 2010 Cayman S, APEX SM-10 18 x 8.5 ET42 and ET50, APEX SM-10 18 x 9 ET46, OZ Alleggerita HLT 18 x 8.5 +53 and Forgeline 18 x 9 +49 without a spacer. Check other wheels with the wheel fitment template.

Fitment