Angry Ass | 340X28 4 Piston Rear Brake System | Competition
Our 340X28 4 Piston Rear Brake System | Competition is designed for customers who want a competition ready rear braking system, which fits under 17” wheels. This system uses AP Racing Radi-Cal 4 piston calipers and 340X28 60 vane J-hook friction discs which are the same caliper and disc type found in big brake kits offered for the most modern and advanced vehicles, from F80 M3s to 991 GT3s. If you have any questions or need more help assembling your system please get in touch.
NOTE: Kits are assembled upon order which can add 5-10 days to your order, if longer we will update you by email.
ATTENTION: Installation requires removal and replacement of the dust shields, which requires cutting your existing units off. Alternatively if replacing your rear wheel bearings you can simply unbolt them, contact us for more information.
CAUTION: The parking brake remains functional but should only be used when stationary and not during any movement! Use of the parking brake while driving will permanently damage the hats and could cause failure of the brake assembly!
Our 340X28 4 Piston Rear Brake System | Competition is designed for customers who want a competition ready rear braking system, which fits under 17” wheels. This system uses AP Racing Radi-Cal 4 piston calipers and 340X28 60 vane J-hook friction discs which are the same caliper and disc type found in big brake kits offered for the most modern and advanced vehicles, from F80 M3s to 991 GT3s. If you have any questions or need more help assembling your system please get in touch.
NOTE: Kits are assembled upon order which can add 5-10 days to your order, if longer we will update you by email.
ATTENTION: Installation requires removal and replacement of the dust shields, which requires cutting your existing units off. Alternatively if replacing your rear wheel bearings you can simply unbolt them, contact us for more information.
CAUTION: The parking brake remains functional but should only be used when stationary and not during any movement! Use of the parking brake while driving will permanently damage the hats and could cause failure of the brake assembly!
Our 340X28 4 Piston Rear Brake System | Competition is designed for customers who want a competition ready rear braking system, which fits under 17” wheels. This system uses AP Racing Radi-Cal 4 piston calipers and 340X28 60 vane J-hook friction discs which are the same caliper and disc type found in big brake kits offered for the most modern and advanced vehicles, from F80 M3s to 991 GT3s. If you have any questions or need more help assembling your system please get in touch.
NOTE: Kits are assembled upon order which can add 5-10 days to your order, if longer we will update you by email.
ATTENTION: Installation requires removal and replacement of the dust shields, which requires cutting your existing units off. Alternatively if replacing your rear wheel bearings you can simply unbolt them, contact us for more information.
CAUTION: The parking brake remains functional but should only be used when stationary and not during any movement! Use of the parking brake while driving will permanently damage the hats and could cause failure of the brake assembly!
Additional Information
Virtually the same weight with significantly increased thermal capacity vs the 300X20 OEM single piston sliding setup
Reduces ~5lbs of unsprung weight with ~3lbs being rotating vs the 328X20 OEM single piston sliding Setup
Asymmetric two piece drop forged caliper body optimized for the dynamic forces experienced during braking
Caliper and all aluminum hardware is hard anodized to handle elevated temps - no paint or powder coat to fail
Ventilated and domed back stainless steel pistons to keep heat out of your brake fluid and ensure a stiff pedal
Anti-knockback springs on pistons
Internal crossovers (which means no external crossover pipes to damage or leak)
Single bolt pad change with common 17mm thick pad shape. No need to remove caliper to change pads
High temperature, low drag piston seals designed to handle track duty
No dust boots - no risk of melting
Disc metallurgy specifically designed to handle competition duty for long term durability
Cost effective lifetime professional caliper rebuild service available through our partner. Pull them off and send them in for a full cleaning and reconditioning
For more information see AP Racing Radi-Cal story
System includes
Left and right AP Racing CP9450 calipers made in UK
Left and right 6061 aluminum caliper mounting brackets with custom caliper studs and M10 K-nuts made in USA
OEM BMW hardware for mounting caliper mounting bracket to hub
Rear stainless steel brake lines manufactured by Spiegler to Angry Ass specifications in the USA with banjo bolts, crush rings and Teknofibra heat protection sleeve
Left and right AP Racing 340X28 60 vane friction discs assembled on 6061 aluminum mounting hats with anti-knockback/rattle springs. Friction discs made in UK and mounting hats made in USA.
OEM BMW rotor retaining screws
Loctite 271
We highly recommend using AP Racing Radi-Cal Brake Fluids, Ferodo pads and having your pads bedded in by us so your rotors are ready to use
If interested in a bit less NVH from the pads moving we recommend the anti rattle blocks
