Honda Fit/Jazz (GK5) Big Brake Kit Upgrade / TTSPORT Direct-Mount WD4
Six years after launch, the Honda Fit GK5 still moves fast on the used market — cheap to buy, fun to drive, and one of the most modified small cars in the segment. But the factory front brake is a single-piston affair that runs out of feel quickly once the rest of the car gets built up. This GK5 owner addressed that with a front-axle swap to the TTSPORT WD4, a forged four-piston direct-mount caliper built specifically for the platform.
The stock GK5 front caliper is a small single-piston unit — fine for daily commuting, but it flexes and fades once you start pushing the car. Swapping to a forged four-piston caliper addresses both the rigidity and the pad contact area in one shot.
The WD4 is a direct-mount design built for the GK5 specifically, so it bolts up to the factory hub without an adapter bracket and still clears the car's 15-inch wheels.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Honda Fit GK5, running 15-inch OEM wheels |
| Front caliper | TTSPORT WD4 forged four-piston direct-mount caliper (Direct-Mount Series), replacing the stock single-piston unit |
| Rotor | Owner's choice — the WD4 caliper can run on the stock rotor, or be paired with a matching TTSPORT rotor for a full front-axle upgrade |
| Caliper construction | 3,000-ton forged aluminum body (no cast components) for reduced weight and higher structural rigidity |
| Finish | Pink caliper finish shown on this build |
Why It Works
A single-piston floating caliper clamps a pad against the rotor from one side and relies on the caliper body sliding to apply the second pad — under hard or repeated braking, that setup flexes and the pedal starts to feel vague. A forged fixed four-piston caliper clamps evenly from both sides with a much stiffer body, so pedal input translates more directly into clamping force.
- Four-piston clamping spreads force across a larger pad area than the stock single-piston caliper, improving bite and modulation.
- Direct-mount fitment engineered for the GK5 means no adapter bracket and clearance under the car's factory 15-inch wheels.
- Forged (rather than cast) construction keeps the caliper lighter while adding stiffness, so less pedal effort is lost to caliper flex.
Installation Gallery
FAQ
What does the TTSPORT WD4 kit change on the Honda Fit GK5?
Do I need new rotors to install the WD4 caliper?
Is the WD4 caliper a universal fit or vehicle-specific?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.