Complete the rear axle of your 992 GT3 and GT3 RS race build with Alcon four-piston calipers, 390x32mm floating rotors and Project Mu H21 pads. This is the rear assembly from Pro-System’s 390mm race package, with dedicated hats and brackets and a clearly defined service-parts specification.
The rear calipers weigh 5.3 lb each and use 31.8 / 34.9mm piston diameters. Paired with 18mm-thick Project Mu H21 pads and 390x32mm rotors, the package brings caliper, rotor and friction dimensions together in a dedicated race configuration.
Alcon Pro-System Porsche 992 GT3 and GT3 R Rear Race Brake Kit
Pro-System draws on more than two decades of motorsport experience to assemble brake packages around Alcon calipers. The value lies in the complete application: rotors, hats, brackets, calipers, pads and mounting hardware chosen together. Dyno-bedded rotors and pads are part of that preparation, bringing the friction components together before installation.
Features
- Alcon four-piston rear competition calipers
- 390x32mm floating two-piece rotors with 48 ventilation vanes
- Dyno-bedded rotors and pads
- Precision-machined aluminum hats and dedicated caliper brackets
- Individually identified replacement rings, pads and mounting parts
Alcon Competition Calipers
The four-piston layout and 31.8 / 34.9mm piston dimensions define this caliper assembly. Dedicated mounting brackets locate the calipers over the matching rotors, while the 18mm pad thickness provides the friction specification for the race package. Use the part references below when servicing the kit so that replacement pads and mounting components match the original configuration.
Floating Two-Piece Rotors
The iron friction ring and aluminum hat operate at different temperatures during hard braking. A floating attachment allows the ring to expand as heat builds, reducing the restraint of a rigid connection. The two-piece construction also makes the kit practical to maintain: a worn rotor ring can be replaced while retaining a serviceable hat.
Ventilation and Heat Management
The 390x32mm rotor rings use 48 ventilation vanes to move air through the friction assembly and help carry away braking heat. Repeated braking places a sustained demand on this assembly, making rotor dimensions, ventilation and the floating attachment important parts of the overall specification. Separate left and right rotor references identify the correct ring for each side.
Fitment and Installation
This is the dedicated race specification, separate from the standard street/track kit. Confirm wheel clearance for your exact wheels before ordering; wheel diameter alone does not establish caliper clearance. Follow the kit installation instructions and use a technician familiar with performance brake systems.
Kit part number: BRK.200621-Rear
Replacement Parts for Your 992 GT3 and GT3 R Rear Race Kit