Li Auto ONE Big Brake Kit Upgrade / TTSPORT Evolution EB8/EP4S
Automakers tune factory brakes for a balance of cost, durability, and everyday comfort — not outright stopping power. That trade-off shows up fast once a driver starts pushing a car harder, and the Li Auto ONE in this build was no exception: a soft pedal and a factory setup that couldn't keep up with how the owner wanted to drive. The fix was a TTSPORT Evolution Series big brake kit, running the EB8 eight-piston caliper up front and the EP4S four-piston caliper (with integrated electronic parking brake) out back.
The owner runs the Li Auto ONE on its stock 20-inch wheels, so the goal was more front-to-rear braking authority and a firmer pedal without giving up wheel fitment.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Li Auto ONE, 20-inch factory wheels |
| Front caliper | TTSPORT EB8 forged eight-piston caliper |
| Front rotor | TTSPORT 405mm high-carbon heat-treated rotor |
| Rear caliper | TTSPORT EP4S forged 4+1-piston caliper (four hydraulic pistons + one EPB actuator) |
| Rear rotor | TTSPORT 380mm high-carbon heat-treated rotor |
| Bracket | Vehicle-specific caliper brackets, front and rear |
| Pads / lines | TTSPORT high-performance street pads, stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and installation hardware |
Each kit ships with the calipers, rotors, vehicle-specific brackets, pads, stainless lines, and the fasteners needed to bolt everything on without machining or spacers.
The front axle uses the TTSPORT EB8 caliper; its full spec sheet is below.
| Brake Caliper | |
|---|---|
| Series | Evolution Series |
| Model / Application | EB8 |
| Axle Position | Front |
| Piston Count | 8-piston |
| Piston Type | Two-piece heat-insulated pistons with dust boots |
| Piston Diameter | 28 mm × 4 / 32 mm × 4 |
| Caliper Dimensions | L 349 mm × W 166 mm × H 98 mm |
| Total Piston Area | 56.8 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 4.95 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 19 in or larger |
| Recommended Rotor Size | Ø380–405 mm × 34 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 107 |
| 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 |
The rear axle pairs with the TTSPORT EP4S caliper, which also handles electronic parking brake duty.
| Brake Caliper | |
|---|---|
| Series | Evolution Series |
| Model / Application | EP4S |
| Axle Position | Rear |
| Piston Count | 4 hydraulic pistons + 1 for EPB actuator |
| Piston Type | 2-piece heat-insulated pistons with dust boots + EPB actuator |
| Piston Diameter | 28 mm × 4 / 27 mm × 1 |
| Caliper Dimensions | L 278 mm × W 202 mm × H 93 mm |
| Total Piston Area | 30.4 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 4.50 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 18 in or larger |
| Recommended Rotor Size | Ø345–380 mm × 28 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 97 |
| 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 |
Why It Works
An eight-piston forged front caliper doesn't just add clamping force — it changes how the pedal reads. A single-piece or floating caliper flexes slightly under load, and that flex is exactly what turns into a soft, low pedal. The EB8's two-piece forged aluminum body resists that flex, so pedal pressure translates more directly into pad-to-rotor force instead of getting absorbed by the caliper itself.
Up front, the EB8's lightened forged body cuts unsprung weight while its open, ventilated design helps pull heat away from the pistons and pads faster than a solid caliper casting would.
- Eight pistons (four 28mm + four 32mm) spread clamping force evenly across a larger pad area, giving 56.8 cm² of total piston area up front.
- The 405mm front rotor carries more mass and surface area than the factory disc, which means more heat capacity and slower fade under repeated hard stops.
- Two-piece heat-insulated pistons keep brake fluid further from rotor heat, protecting pedal feel during sustained braking.
- The EP4S rear caliper folds the electronic parking brake actuator into the same forged body as the four hydraulic pistons, so upgrading the rear brakes doesn't mean losing EPB function.
- Vehicle-specific caliper brackets place the EB8 and EP4S calipers at the correct offset for the Li Auto ONE's stock 20-inch wheels — no spacers, no guesswork.
Installation Gallery
Does the TTSPORT EP4S rear caliper still work with the Li Auto ONE's electronic parking brake?
Will the EB8 front / EP4S rear kit clear the Li Auto ONE's stock 20-inch wheels?
What's included in this TTSPORT big brake kit?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.