BMW 3 Series (E90) Big Brake Kit Upgrade / TTSPORT Evolution EB4
The BMW 3 Series (E90) is still one of the best-driving cars of the E-chassis era, but the factory brakes were tuned for comfort, not commitment. Push it hard on a mountain road or a track day and the pedal gets soft up top, with response that lags behind what the chassis can actually do. This E90 owner addressed that with a front-axle upgrade to the TTSPORT Evolution Series EB4 four-piston kit — a bolt-on fix that firms up pedal feel without overloading the rest of the brake system.
The E-chassis 3 Series has plenty of room to work with behind 18–19 inch wheels, which makes it a good candidate for a proper caliper and rotor upgrade rather than just a pad-and-fluid refresh. The goal here was a tighter, more predictable pedal for daily driving and the occasional spirited run — not a full race setup.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BMW 3 Series (E90), 18-inch wheels |
| Front caliper | TTSPORT Evolution Series EB4 forged four-piston caliper |
| Front rotor | TTSPORT 355mm high-carbon rotor with a wave-drilled face |
| Bracket | Vehicle-specific custom caliper bracket |
| Pads / lines | TTSPORT high-performance brake pads, TTSPORT stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts and fixing hardware |
Below is TTSPORT's official spec sheet for the EB4 caliper used in this build.
| Brake Caliper | |
|---|---|
| Series | Evolution Series |
| Model / Application | EB4 |
| Axle Position | Front |
| Piston Count | 4-piston |
| Piston Type | Two-piece heat-insulated pistons with dust boots |
| Piston Diameter | 40 mm × 2 / 44 mm × 2 |
| Caliper Dimensions | L 289 mm × W 151 mm × H 83 mm |
| Total Piston Area | 55.5 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 3.80 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 18 in or larger |
| Recommended Rotor Size | Ø355–380 mm × 32 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 99 |
| Caliper Mounting Type | Radial mount with vehicle-specific caliper brackets |
| Brake Line Fitting Type | Vehicle-specific fittings; caliper-side and chassis-side fittings vary by application |
Per TTSPORT's spec sheet, the EB4 caliper is built for 18-inch wheels or larger with a minimum spoke clearance of 99mm — which lines up with the 18-inch wheels on this car, so no spacers were needed to clear the new hardware.
Why It Works
- The EB4's two-piece forged aluminum body, with an asymmetric, machined-out design, cuts weight while keeping pressure distribution even across all four pistons — that's what firms up the front and back of the pedal stroke compared to a flex-prone stock caliper.
- Stepping up to a 355mm rotor adds swept area and mass over the factory disc, giving the system more heat capacity for repeated hard stops on a downhill run or a track session.
- Two-piece heat-insulated pistons with dust boots and high-temp seals hold up better under sustained heat and are also compatible with carbon-ceramic rotors if the owner upgrades later.
- A vehicle-specific caliper bracket keeps the whole assembly fitting behind the OEM 18-inch wheel with no spacers required.
Installation Gallery
FAQ
What kit was installed on this BMW 3 Series E90?
Does the EB4 kit fit under stock 18-inch wheels?
What is the EB4 caliper made from?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.