AUDI TT TTS 8J TFSi TDi QAUTTRO REAR BIG BRAKE DISC UPGRADE CONVERSION KIT 310M February 29, 2024 admin FOR CONVERTING YOUR REAR BRAKES TO VENTED. 310MM DIAMETER VENTED REAR BRAKE DISC CONVERSION. 2 X NEW REAR VENTED DRILLED GROOVED 310MM DIAMETER BRAKE DISC. 2 X NEW REAR ELECTRIC BRAKE CALIPERS COMPLETE WITH CARRIERS + BRAKE PADS.