Honda Fit/Jazz (GK5) Big Brake Kit Fitment / TTSPORT Direct-Mount Series
Shop for a big brake kit online and it's easy to fall for a caliper's looks or spec sheet before you know whether it will actually bolt up. If you're talking to the factory that builds the kit rather than a local shop, they'll usually ask for one thing before quoting your car: your VIN.
A VIN, also called a chassis number, works like a car's ID card. Decode it and a fitment specialist can pull the actual production data for your car - trim, brake hardware, wheel specs - instead of guessing from the model name alone.
Why TTSPORT Asks for Your VIN
TTSPORT's fitment team runs the VIN before quoting parts, checking four things: the vehicle's stock brake hardware, the production-batch chassis details, the exact wheel specs, and the caliper trim that fits how the car is actually driven.
| VIN Data Point | What It Confirms |
|---|---|
| Vehicle model & trim | Stock master cylinder output and OEM caliper type, so a new caliper's fluid demand can be matched to what the pedal can actually deliver |
| Chassis / production batch | Exact hub and wheel-center data, since the same model built in different years or batches can differ on these numbers |
| Wheel specs | Rim diameter, width (J-value), offset (ET), and hub bore (X-value), which set how much clearance is actually available behind the wheel |
| Caliper version | Whether a Track, Street, or GT trim of a given caliper best matches how the car is driven |
Why It Works: Matching the Master Cylinder, Wheel, and Caliper
Every brake system runs on a master cylinder feeding fluid to the calipers. If the master cylinder can't move enough fluid, the caliper never sees its full mechanical potential. As an example: a stock single-piston caliper might only need about 22ml of fluid per second under full braking, matched to what the OE master cylinder supplies. Swap in a six-piston caliper that needs roughly 400ml per second to hit its best performance, and that same master cylinder can't keep up - full-brake effectiveness can drop to 60% or less of what the six-piston caliper is capable of, which is a real safety concern, not just a lost bit of bite.
Wheel geometry matters just as much. Rim width (J-value), offset (ET), and hub bore (X-value) all determine how much room is actually left behind the wheel for a bigger caliper. Most stock wheels need to be swapped for aftermarket wheels sized for the kit. A handful of platforms are the exception - the Honda Fit GK5, for example, has direct-mount calipers from both TTSPORT and Wilwood built to clear the factory wheel with no wheel change needed.
This is also why the chassis number matters beyond the model name: the same car built across different years or production runs can carry different hub and wheel-center numbers, so the VIN pins down which exact hardware will actually fit.
Choosing the Right Caliper Version
Once the model, chassis, and wheel data line up, the same caliper is often offered in more than one trim. Which one makes sense comes down to how the car gets driven.
- Track version - built for repeated hard stops on track days and competition
- Street version - sized for everyday street driving
- GT version - a middle ground for daily drivers who want more margin than a street setup without going full track spec
Case Gallery
Frequently Asked Questions
Why does TTSPORT need my VIN to recommend a brake kit?
Can a big brake kit fit my stock wheels?
What's the difference between Track, Street, and GT caliper versions?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.