BMW 3 Series (G20) Big Brake Kit Upgrade / TTSPORT Classic 8703
The new-generation BMW 3 Series (G20 standard wheelbase / G28 long wheelbase) is lighter and stiffer than its predecessor, but the factory brakes still feel soft when you're actually pushing the car. For this build, the owner went with a front-six, rear-four TTSPORT kit sized to work behind the car's factory 18-inch wheels — and because the G20's rear axle runs an electronic parking brake, the rear caliper had to be an EPB-specific unit, not a standard fixed caliper.
Power for this 325i/325Li-spec car comes from BMW's B48B20B 2.0T four-cylinder, rated at 184 hp with the 8-speed automatic — plenty of motor to make a soft factory brake pedal feel like the weak link. The fix here was a matched front and rear TTSPORT kit rather than just swapping pads and rotors.
Vehicle & Kit Specs
Here's the hardware breakdown for this install, front and rear:
| Item | Specification |
|---|---|
| Vehicle | BMW 3 Series G20/G28, 18-inch factory wheels, B48B20B 2.0T / 184 hp, 8-speed automatic |
| Front caliper | TTSPORT TT8703 cast monobloc six-piston caliper (one-piece cast aluminum) |
| Front rotor | TT 355 x 32mm high-carbon, heat-treated, curved-vane rotor |
| Rear caliper | TTSPORT TT6411 cast four-piston caliper |
| Rear rotor | TT 355 x 28mm high-carbon, heat-treated, curved-vane rotor |
| EPB caliper | TTSPORT universal electronic parking brake caliper, integrates with the factory EPB switch |
| Brake lines | TTSPORT stainless steel braided lines |
Why It Works
The TT8703 front caliper is a one-piece cast aluminum body, which is what keeps clamping force consistent under repeated hard stops instead of flexing away pedal feel. The larger, high-carbon 355mm rotors add rotational mass and surface area over the stock discs, which means more heat capacity before the brakes start to fade on a spirited drive or a track day.
- Cast six-piston front / four-piston rear layout adds pad contact area over the factory single-piston sliding calipers, translating to a firmer, more progressive pedal
- The rear TT6411 pairs with a dedicated TTSPORT EPB caliper, so the car's electronic parking brake and auto-hold keep working normally after the swap
- Both kits were specced to clear the car's stock 18-inch wheels with no spacers needed
Installation Gallery
FAQ
Does this TTSPORT kit fit under the BMW 3 Series' factory wheels?
Does the rear kit work with the G20's electronic parking brake?
What's included in the front and rear brake kits?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.