Daihatsu Copen Big Brake Kit Upgrade / TTSPORT Slim SL6S
Small-wheel cars have always been the hard case for brake upgrades. If your wheels are 15 or 16 inches, most performance calipers simply don't clear the spokes without a flange spacer or a wheel swap — and that defeats the point of keeping a light, original-fitment car. The TTSPORT SL6S was built to close that gap, and its first install, on a Daihatsu Copen, shows it bolting up behind the car's stock wheels with no spacers and no wheel change.
The Copen is exactly the kind of car this problem shows up on: light body, tight wheel wells, small factory wheels. TTSPORT's existing Slim Series calipers — the SL6 for 17-18 inch wheels and the SL8 for 19-20 inch wheels — had already proven the "fits without spacers" formula on bigger-wheel cars. Owners running 15-16 inch wheels kept asking for the same thing, which is what led to the SL6S.
Vehicle & Kit Specs
The SL6S isn't a scaled-down SL6 — it's a separate design pass on wheel clearance, rotor diameter, caliper outline, and hydraulic layout, built around the tighter dimensions of 15-16 inch wheels.
| Item | Specification |
|---|---|
| Vehicle | Daihatsu Copen, stock 15-16 in OEM wheels |
| Front caliper | TTSPORT SL6S forged six-piston caliper (Slim Series) |
| Bracket | Vehicle-specific caliper bracket, radial mount |
| Wheel fitment | Direct fit behind stock 15-16 in wheels, no flange spacers, no wheel upgrade |
Below is the official spec sheet for the SL6S caliper used on this build.
| Brake Caliper | |
|---|---|
| Series | Slim Series |
| Model / Application | SL6S |
| Axle Position | Front |
| Piston Count | 6-piston |
| Piston Type | One-piece heat-insulated pistons |
| Piston Diameter | 28 mm × 2 / 30 mm × 2 / 36 mm × 2 |
| Caliper Dimensions | L 268.5 mm × W 121.6 mm × H 74.9 mm |
| Total Piston Area | 46.8 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 1.96 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 15 in or larger |
| Recommended Rotor Size | Ø285–295 mm × 28 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 75 |
| 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
None of this required cutting corners on the caliper itself — the SL6S still uses the same construction principles as TTSPORT's larger Slim Series calipers, just packaged tighter.
- Opposed six-piston layout with a mixed 28/30/36mm bore spread distributes clamping force more evenly across the pad than a stock single- or twin-piston caliper, which is what gives a more linear pedal response.
- The two-piece forged aluminum body resists flex under hard braking better than a cast caliper, which keeps pedal feel consistent instead of going soft as loads climb.
- A compressed caliper outline was the specific engineering target for this size class — the whole point was to shrink outer dimensions without shrinking rigidity or piston area, so it clears the spokes on 15-16 inch wheels.
- One-piece heat-insulated pistons help slow heat transfer into the brake fluid, which supports steadier braking on repeated hard stops or descents rather than a caliper built purely for occasional street use.
Installation Gallery
FAQ
Does the TTSPORT SL6S fit under stock 15-16 inch wheels without spacers?
What is the piston configuration of the TTSPORT SL6S caliper?
What rotor size does the SL6S pair with?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.