Honda Fit/Jazz (GK5) Big Brake Kit Upgrade / TTSPORT Classic 5440
Six years after launch, the Honda Fit GK5 still moves fast on the used market, and it's easy to see why — light curb weight, a stiff chassis, and a factory personality that already leans toward "pocket sports car." That combination also makes it a magnet for modification, and one of the first things owners run into is the stock brake package running out of confidence once the car sees real driving. This build swaps the front calipers and rotors for a TTSPORT setup built to work behind the GK5's factory 15-inch wheels.
The stock GK5 caliper is a single-piston sliding design — light and cheap to build, but it flexes under hard braking and gives the pedal a soft, less predictable feel as the pads heat up. Swapping in a fixed, multi-piston caliper addresses that flex directly, which is the core of this upgrade.
Vehicle & Kit Specs
This is a front-axle upgrade built around a small-footprint caliper so it clears the car's 15-inch wheels with no spacers.
| Item | Specification |
|---|---|
| Vehicle | Honda Fit (GK5), 15-inch factory wheels |
| Front caliper | TTSPORT 5440 Classic Series forged four-piston caliper |
| Front rotor | TTSPORT 285mm x 24.5mm high-carbon heat-treated slotted ("fishhook") rotor |
| Lines | TTSPORT stainless steel brake lines |
Below is the official spec sheet for the TTSPORT 5440 caliper used in this build.
| Brake Caliper | |
|---|---|
| Series | Classic Series |
| Model / Application | 5440 |
| Axle Position | Front |
| Piston Count | 4-piston |
| Piston Type | Star-profile racing pistons without dust boots |
| Piston Diameter | 38 mm × 2 / 41 mm × 2 |
| Caliper Dimensions | L 276 mm × W 138 mm × H 80 mm |
| Total Piston Area | 49.1 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 2.65 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 17 in or larger |
| Recommended Rotor Size | Ø330–345 mm × 28 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 86 |
| 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
- A two-piece forged caliper body doesn't flex the way a stock sliding caliper does, so pedal input translates more directly into clamping force instead of getting absorbed by caliper deflection.
- Stepping up to a 285mm x 24.5mm rotor adds mass and surface area over the factory disc, giving the system more thermal capacity before pad and fluid performance start to fade.
- With an 86mm minimum spoke clearance requirement, the 5440 caliper is sized to tuck behind the GK5's 15-inch factory wheels without forcing a wheel change or spacers.
- Stainless steel lines replace the factory rubber hoses, cutting down on the line expansion that contributes to a spongy pedal under repeated hard stops.
The pink finish on this particular build is a color option rather than a functional change, but it shows off the caliper's forged lines and the slotted pattern on the 285mm rotor once everything is tucked behind the wheel.
Installation Gallery
Frequently Asked Questions
Does the TTSPORT 5440 kit fit under 15-inch wheels?
What's included in the TT5440 big brake kit used on this GK5?
What kind of caliper is the TTSPORT 5440?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.