Honda Fit/Jazz (GK5) Big Brake Kit Upgrade / TTSPORT Direct-Mount WD4
The third-generation Honda Fit (GK5) is light, quick, and cheap to modify — which is exactly why so many owners end up disappointed by its brakes. This car came in with the factory setup still in place: a cast-iron, single-piston front caliper doing all the work. It stops the car, technically, but it doesn't inspire much confidence once you start driving the Fit the way its chassis wants to be driven. The fix here was a TTSPORT Slim WD4 kit — a forged four-piston caliper and a 262x21mm high-carbon, heat-treated drilled rotor, running TTSPORT stainless lines, all sized to clear the car's stock 15-inch wheels.
At just over a ton, the GK5 doesn't need a huge rotor to stop hard — it needs a caliper and pad that can bite consistently and a setup that doesn't add unnecessary weight at the corner. The stock single-piston caliper simply wasn't built for repeated hard stops.
The install swaps the whole front corner — caliper, rotor, and lines — while staying within the factory 15-inch wheel fitment, no spacers involved.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Honda Fit GK5 (3rd generation), 15-inch OEM wheels |
| Front caliper | TTSPORT WD4 forged four-piston caliper, approx. 1.8 kg per caliper |
| Front rotor | 262x21mm high-carbon, heat-treated, drilled rotor |
| Lines | TTSPORT stainless steel brake lines |
Why It Works
A single-piston floating caliper only pushes the pad on one side and relies on the caliper body sliding to clamp the other — under repeated hard braking that slack and flex shows up as a soft, inconsistent pedal. A forged four-piston caliper clamps both pad faces directly and evenly, and the forged aluminum body flexes far less than the stock cast-iron piece under load, so pedal feel stays firm and predictable.
- Forged four-piston caliper replaces the factory single-piston unit for more even, consistent clamping force
- 262x21mm drilled rotor adds surface area and mass for heat capacity beyond the stock disc
- Sized to fit behind the GK5's 15-inch OEM wheels — no spacers needed
- At roughly 1.8 kg per caliper, the forged unit helps keep unsprung mass in check on a car that's already light on its feet
Because the caliper and rotor were sized specifically for the Fit's smaller wheel diameter, none of that comes at the cost of wheel fitment — the kit was built to bolt into the stock wheel well.
Installation Gallery
What's different about the TTSPORT WD4 kit compared to the stock GK5 front brake?
Will the WD4 big brake kit fit under the Fit GK5's 15-inch wheels?
Does the WD4 kit include brake lines?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.