Audi A4 allroad (B9) Big Brake Kit Upgrade / TTSPORT Classic 8703
The Audi A4 allroad (B9) came to China with a 2.0L TFSI four-cylinder turbo, a 7-speed S-tronic gearbox, 211 hp, 350 Nm of torque, and quattro all-wheel drive — enough to hit 0-62 mph in 6.9 seconds. It's not a full-blown performance sedan, but it moves. The factory single-piston brakes, according to the owner, felt soft and a little overwhelmed once you actually used that power. The fix here didn't require any exotic parts: a TTSPORT TT8703 six-piston front kit and a matching set of 355mm high-carbon heat-treated rotors, front and rear.
The kit was built around the car's stock 18-inch wheels — no wheel or spacer change needed to make the bigger rotors and calipers work.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Audi A4 allroad (B9), 2.0 TFSI quattro, 18-inch factory wheels |
| Front caliper | TTSPORT TT8703 cast-aluminum six-piston monobloc caliper |
| Front rotor | TT 355x32mm high-carbon heat-treated drilled rotor |
| Rear rotor | TT 355x12mm high-carbon heat-treated rotor, paired with the retained OEM single-piston rear caliper/parking-brake motor |
| Lines | TTSPORT stainless steel brake lines |
Why It Works
- The TT8703 caliper is cast in one piece from aluminum alloy — a rigid, non-flexing body under hard braking holds pad-to-rotor contact steady instead of letting the caliper flex outward and eat pedal travel.
- Six pistons spread clamping force across a larger pad, which is a big part of why the factory single-piston setup felt soft by comparison.
- Jumping from the stock rotor to a 355mm high-carbon heat-treated disc adds mass and surface area, which means more heat capacity and less fade on repeated hard stops.
- Built-in dust boots on the TT8703 caliper keep grit out of the piston bores, which cuts down on the maintenance a big six-piston setup would otherwise need.
Side-by-side, the difference between the factory single-piston caliper and the TT8703's six-piston, cast-aluminum body explains the pedal complaint on its own.
Rear Rotor Solution for Other Audi Models
Rear rotor upsizing has always been a headache on Audi platforms because clean direct-replacement options are scarce. TTSPORT built a cross-drilled 355x22mm rear rotor specifically to close that gap — it's designed as a direct swap, with a matching bracket, for Audi performance models such as the A8 that need a larger rear rotor without a custom fabrication job.
Paired with its dedicated bracket, this rotor bolts in place of the OEM disc on supported Audi models, matching stock geometry while stepping up rotor size.
Installation Gallery
FAQ
What wheel size does this TTSPORT kit fit on the Audi A4 allroad (B9)?
What's in the front TTSPORT kit used on this Audi A4 allroad?
Did the rear brakes get new calipers too?
Does TTSPORT offer a rear big-rotor option for other Audi models?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.