Ford Mustang Big Brake Kit Upgrade / TTSPORT Classic 8657S
The Ford Mustang has never lacked motor. What it's often lacked is a brake pedal that matches the powertrain. Factory calipers on the Mustang are tuned for daily comfort and cost, not for repeated hard stops from triple-digit speeds — which leaves owners with a soft pedal and a nagging feeling that stopping power hasn't kept pace with the go-power. This case swaps in a TTSPORT front-six/rear-four big brake kit built specifically to close that gap.
As a rear-drive, high-output muscle car, the Mustang puts real load on its brakes under hard use. Owners running this car hard on backroads or at track days typically report three things: stopping distances that grow at speed, noticeable fade after a few consecutive hard stops as the small factory rotors soak up heat, and a pedal that feels soft and vague rather than sharp and predictable — a symptom of factory tuning aimed at comfort rather than feedback.
Why a Mustang Needs a Front-Six, Rear-Four Setup
For American muscle cars, the priority isn't just bigger front brakes — it's balancing front and rear braking force. TTSPORT's recommendation for this build pairs a six-piston front caliper with a four-piston rear caliper, rather than just bolting on a big front kit and leaving the rear stock.
The TTSPORT 8657S six-piston front caliper adds bite and clamping stability up front for quicker, more linear stops. Behind it, the TTSPORT ES4 four-piston rear caliper (with electronic parking brake) keeps rear braking force proportional, which helps prevent the tail from stepping out under hard braking — the same reasoning that goes into any brake bias upgrade, just applied here with matched hardware instead of guesswork.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Ford Mustang, 19-inch wheels |
| Front caliper | TTSPORT Classic 8657S forged six-piston caliper |
| Front rotor | TTSPORT 380mm high-carbon rotor |
| Rear caliper | TTSPORT Evolution ES4 forged four-piston caliper with electronic parking brake |
| Rear rotor | TTSPORT 380mm high-carbon rotor |
| Bracket | Custom vehicle-specific caliper mounting brackets, front and rear |
| Pads / lines | TTSPORT high-performance brake pads, stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fastening hardware |
Below are the official spec sheets for the two calipers used in this build — the TTSPORT Classic 8657S up front and the TTSPORT Evolution ES4 out back.
| 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 |
| Brake Caliper | |
|---|---|
| Series | Evolution Series |
| Model / Application | ES4 |
| Axle Position | Rear |
| Piston Count | 4-piston |
| Piston Type | Two-piece heat-insulated pistons with dust boots |
| Piston Diameter | 28 mm × 2 / 32 mm × 2 |
| Caliper Dimensions | L 255 mm × W 139 mm × H 74 mm |
| Total Piston Area | 28.4 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 2.80 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) | 90 |
| 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
- Forged aluminum caliper bodies flex less than the factory sliding calipers under hard braking, so pedal pressure translates directly into clamping force instead of getting absorbed by caliper deflection — that's the source of the firmer, more linear pedal feel.
- The 380mm rotors front and rear carry more thermal mass than the stock discs, so they absorb more heat before temperatures climb high enough to fade the pads — which is what limits repeated hard stops on the factory setup.
- Six-piston front / four-piston rear isn't just about raw front bite — it keeps rear braking proportional to the front, which is what keeps the car settled and predictable under hard braking rather than shifting weight and grip unevenly.
- Vehicle-specific caliper brackets locate the calipers to clear the factory 19-inch wheels, and the ES4 rear caliper retains electronic parking brake function so nothing about daily drivability is lost.
Installation Gallery
Frequently Asked Questions
What wheel size does this Mustang big brake kit fit?
Does the rear caliper work with the factory electronic parking brake?
What rotor size is used front and rear?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.