AP Racing CP9449 Pro 5000R 378mm Rear Big Brake Kit – BMW F8X M2 M3 M4

The AP Racing Pro 5000R Rear Big Brake Kit (378x32mm) for the BMW F8X platform is designed to complement high-performance front brake setups and deliver balanced, consistent braking performance for fast road, track day and motorsport applications.

Paired with 378x32mm two-piece rear discs, lightweight aluminium bells and precision mounting brackets, this system significantly improves rear braking stability, thermal capacity and durability compared to the factory rear braking system. The larger disc diameter and floating disc design improve heat management under repeated heavy braking, helping maintain consistent braking performance during demanding track sessions.

This kit is supplied with high-quality aftermarket two-piece discs/rotors, providing a cost-effective and durable solution for track-driven vehicles. At Clubsport Garage we have tested these discs ourselves on our F87 M2 Competition track car with excellent results in terms of performance, durability and consistency. A number of customers who previously ran AP Racing discs have also switched to these aftermarket discs/rotors and reported similarly positive results, making them a compelling option for those looking to reduce running costs without sacrificing performance.

The discs are available in grooved or J-Hook patterns and are supplied pre-assembled with bells and mounting hardware already installed, ensuring correct fitment and simplifying installation.

Like the front AP Racing motorsport calipers, the calipers used in this kit do not utilise dust seals. This motorsport design allows them to operate reliably at much higher temperatures than typical road calipers. As a result, they are ideal for track and motorsport environments but may require more frequent cleaning and maintenance when used on the road, particularly in harsh weather conditions.

An optional anti-rattle/pad retention spring kit is also available for customers who plan to use the car on the road and want to minimise brake pad movement and noise during everyday driving.

Designed as a bolt-on upgrade using supplied brackets and hardware, this kit mounts directly to the factory rear uprights and delivers a motorsport-grade rear braking solution that pairs perfectly with AP Racing front brake kits.

Further information below.