BMW 3 Series Big Brake Kit Upgrade / TTSPORT Classic 9040
The BMW 3 Series has built its reputation on driving feel, so when the brakes are the weak link, it shows fast. This 3 Series rolls on 18-inch wheels and picked up a front six-piston / rear four-piston TTSPORT big brake kit — a straightforward way to close the gap between what the chassis can do and what the stock calipers could actually hold back.
Up front, the car runs a TTSPORT TT9040 forged six-piston caliper paired with a 355x32mm high-carbon, heat-treated, drilled rotor. Out back, a TT8901 forged four-piston caliper clamps a 345x28mm rotor of the same spec. Both ends were sized to sit behind the car's existing 18-inch wheels.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BMW 3 Series, 18-inch wheels |
| Front caliper | TTSPORT TT9040 forged six-piston caliper |
| Front rotor | TTSPORT 355x32mm high-carbon heat-treated drilled rotor |
| Rear caliper | TTSPORT TT8901 forged four-piston caliper |
| Rear rotor | TTSPORT 345x28mm high-carbon heat-treated drilled rotor |
Why It Works
A forged fixed caliper doesn't flex under load the way a stock sliding caliper can, so pedal input translates more directly into clamping force instead of getting absorbed by caliper deflection. Going to six pistons up front and four in the rear also spreads clamping load across a larger pad area, which helps pedal feel stay consistent rather than going soft as the pads heat up.
The larger 355mm front and 345mm rear rotors add rotational mass and surface area, giving the system more thermal capacity before fade sets in, while the drilled faces help ventilate gas and debris off the pad surface. Because the kit was sized around the car's stock 18-inch wheels, it went on without needing spacers — and per the source, it actually fills the wheel opening better than the factory brakes did.
- Forged fixed calipers front and rear reduce flex versus the stock sliding setup
- 355mm/345mm rotors add heat capacity for more consistent stopping power
- Fits behind the factory 18-inch wheels with no spacers mentioned
Installation Gallery
Does this TTSPORT big brake kit fit behind the BMW 3 Series' stock 18-inch wheels?
What does this BMW 3 Series brake upgrade include front and rear?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.