BMW 5 Series Big Brake Kit Upgrade / TTSPORT Classic 8703
A BMW 5 Series is a car that's supposed to feel composed under hard braking, but the factory calipers on this one weren't keeping up with the rest of the car's road manners. The owner went with a full front-and-rear TTSPORT big brake kit — a TT8703 six-piston setup up front and a TT8903 four-piston setup in back — all tucked behind the stock 19-inch wheels.
Up front, the car gets a custom tri-color TT8703 cast six-piston caliper paired with a 380x34mm curved-slot rotor. The bigger rotor diameter and thicker disc fill out the factory 19-inch wheel a lot more convincingly than the stock brakes ever did, while adding real swept area for the pads to work with.
Out back, a matching tri-color TT8903 monobloc-cast four-piston caliper runs on a 380x28mm curved-slot rotor with an anti-rust coating. The curved slot pattern helps keep the rotor face clean of pad deposits, and the coating is there to slow surface corrosion over time — a small detail that keeps the whole setup looking as good as it stops.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BMW 5 Series, 19-inch factory wheels |
| Front caliper | TTSPORT TT8703 cast six-piston caliper, custom tri-color finish |
| Front rotor | 380x34mm curved-slot rotor |
| Rear caliper | TTSPORT TT8903 monobloc-cast four-piston caliper, matching tri-color finish; EPB-compatible caliper also offered |
| Rear rotor | 380x28mm curved-slot rotor with anti-rust coating |
| Hardware | TTSPORT gold-finish caliper bridge hardware and mounting kit |
Why It Works
- Cast six/four-piston calipers clamp more evenly across a wider pad than the OEM single- or dual-piston units, which is what firms up pedal feel and cuts down on flex under hard stops.
- Larger 380mm front and rear rotors add mass and surface area, giving the system more thermal capacity so braking stays consistent instead of fading on repeated hard stops.
- The whole kit was sized to clear the car's stock 19-inch wheels, so the owner gets the upgraded hardware without switching wheels or running spacers.
- The curved-slot rotor face and anti-rust coating keep the braking surface cleaner and better protected, which helps preserve consistent pedal feel over time.
Installation Gallery
Does this TTSPORT big brake kit fit behind the BMW 5 Series' factory 19-inch wheels?
Is an electronic parking brake (EPB) caliper option available for the rear kit?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.