AP Racing Road Rear Brake Kit 380mm - BMW E9X M3, 1M

The AP Racing by Essex Road Brake Kit is a rear brake upgrade for BMW E90, E92 and E93 M3 and the 1M Coupe. It pairs AP Racing CP9541 World Radi-CAL II four-piston calipers with 380 x 28mm, 48-vane AP Racing J Hook discs on fully floating aluminum hats, built for fast road driving and track days.

Why upgrade

The kit removes about 10 lb of unsprung weight from the rear of the car compared with the OEM, despite being far larger. Each caliper weighs 7.1 lb without pads, against 8.1 lb for the factory caliper. Each two-piece disc weighs 16.4 lb, compared with 21 lb for the original 350mm disc. The 16.9mm pad is thicker than the 16.1mm factory pad, so it lasts longer and absorbs more heat between changes. Painted calipers with dust boots add durability in wet and dirty conditions. Low noise, vibration and harshness give an OE-like feel in daily driving. Pistons are sized to maintain brake bias and work with the OEM master cylinder and ABS.

Caliper and disc construction

On the BMW E9X M3, 1M, the CP9541 caliper mounts radially on a dedicated bracket at 195mm centers with a 36mm offset, with an M10x1.0 inlet thread. It is a four-piston AP Racing caliper. The 380 x 28mm discs use 48-vane AP Racing J Hook rings on 6061 hard anodized aluminum hats with fully floating hardware.

Features

• AP Racing CP9541 four-piston calipers
• 380 x 28mm, 48-vane J Hook discs on floating hats
• 16.9mm thick brake pads
• Pistons sized for the OEM master cylinder and ABS
• Two-piece discs on 6061 aluminum hats

What's Included

• One pair AP Racing CP9541 World Radi-CAL II four piston calipers
• One pair 380x28mm AP Racing CP5914, 72 vane, J Hook 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
• One set of Ferodo DS2500 Brake Pads
• Detailed installation instructions

Specifications

Video

Fitment notes

This rear kit fits the vehicles in the table below, which we confirmed against two sources using US model years. Check your wheel with the Essex wheel fitment template before ordering.

Fitment