Mercedes-Benz CLA Big Brake Kit Upgrade / TTSPORT Classic 8657S
Since its debut in 2013, the Mercedes-Benz CLA has carried the "four-door coupe" torch in the compact luxury segment, blending Mercedes styling with a genuinely sporty attitude. From the original C117 to the more aggressive current-gen C118, every CLA generation has pushed a little harder toward real performance. But more power only gets a car so far — the thing that actually separates a fast car from a fast, confidence-inspiring car is how well it stops.
However hard you accelerate or push a corner, everything comes down to what happens when you hit the brake pedal. Factory brake systems on cars like the CLA are tuned for comfort, cost, and everyday driving — which usually means they're conservative by design. Swapping in the TTSPORT 8657S six-piston kit isn't just about track days; it's about having real stopping margin for the sudden moments that show up on regular city streets.
Vehicle & Kit Specs
This CLA runs its factory 18-inch wheels, so fitment was a key part of the build alongside the actual brake hardware.
| Item | Specification |
|---|---|
| Vehicle | Mercedes-Benz CLA, 18-inch factory wheels |
| Front caliper | TTSPORT 8657S forged six-piston caliper |
| Front rotor | TTSPORT 355mm high-carbon rotor |
| Bracket | Custom vehicle-specific caliper mounting bracket |
| Pads / lines | TTSPORT high-performance pads, TTSPORT stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fixing hardware |
Below is the full official spec sheet for the TTSPORT 8657S caliper used in this build.
| Brake Caliper | |
|---|---|
| Series | Classic Series |
| Model / Application | 8657S |
| Axle Position | Front |
| Piston Count | 6-piston |
| Piston Type | Two-piece heat-insulated pistons with dust boots |
| Piston Diameter | 30 mm × 2 / 34 mm × 2 / 38 mm × 2 |
| Caliper Dimensions | L 350 mm × W 165 mm × H 92.64 mm |
| Total Piston Area | 55.0 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 4.05 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 18 in or larger |
| Recommended Rotor Size | Ø355–405 mm × 32–34 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 |
Why It Works
The 8657S is built as a two-piece forged aluminum caliper with a science-based hollow-out design, which keeps weight down without giving up rigidity — the reason a forged fixed caliper holds pedal feel steady under hard, repeated braking where a flexing stock caliper starts to feel mushy.
- Progressive six-piston layout delivers linear, controllable pedal feel instead of an on/off bite.
- The 355mm rotor adds mass and surface area over the factory disc, giving the system more heat capacity before fade sets in.
- Two-piece heat-insulated pistons with dust boots keep clamping force consistent as temperatures climb.
- The vehicle-specific bracket and kit geometry let the setup tuck behind the CLA's stock 18-inch wheels — no wheel or spacer changes needed.
Installation Gallery
FAQ
What does the TTSPORT 8657S kit include for the Mercedes CLA?
Will the 8657S big brake kit fit behind this CLA's factory wheels?
What piston setup does the TTSPORT 8657S caliper use?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.