BYD Song L (DM-i) Big Brake Kit Upgrade / TTSPORT Slim SL6
The BYD Song family has built a following on hybrid efficiency and everyday practicality, but as the powertrain got stronger, the factory brakes started falling behind. Song L DM-i owners kept reporting the same thing: a soft pedal under hard braking, with stopping power that couldn't quite keep up with how quickly the car accelerates. Many were also reluctant to add wheel flange adapters just to clear a bigger brake kit — extra cost, extra hassle, and a nagging worry about wheel-hub fitment. This case shows a more direct fix.
The complaint was consistent: a mushy initial pedal, especially in emergency stops, that didn't match the car's power. Rather than reach for flange adapters, the shop built a kit designed to bolt straight onto the Song L's factory 18-inch wheels.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BYD Song L DM-i, 18-inch factory wheels |
| Front caliper | TTSPORT SL6 forged six-piston caliper (Slim Series) |
| Front rotor | TTSPORT 355mm vented rotor |
| Rear rotor | TTSPORT 355mm vented rotor |
| Bracket | Custom vehicle-specific caliper bracket |
| Pads / lines | TTSPORT performance brake pads, TTSPORT stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fixing hardware |
The front calipers used in this build are the TTSPORT SL6, part of the Slim Series line designed to fit under smaller factory wheels without spacers. Full specs below.
| Brake Caliper | |
|---|---|
| Series | Slim Series |
| Model / Application | SL6 |
| 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 350 mm × W 135 mm × H 120 mm |
| Total Piston Area | 46.8 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 3.60 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 17 in or larger |
| Recommended Rotor Size | Ø330–355 mm × 28 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 82 |
| 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 |
Wheel spoke clearance is the deciding factor for any spacer-free brake upgrade, so the caliper body's outer profile was checked against the Song L's 18-inch factory wheel before this kit was specified.
Why It Works
- The SL6 caliper's dimensions were engineered against the common inner diameter and spoke geometry of 18-inch wheels, so it bolts on directly without flange adapters or wheel changes.
- Piston sizing was tuned to work with the Song L's stock master cylinder, so pedal travel stays linear rather than feeling "grabby" at the top of the stroke — you get a firmer, more predictable bite instead of an unpredictable one.
- The six-piston opposed layout spreads clamping force evenly across the pad, which helps resist the fade that shows up after repeated hard stops or a stretch of mountain-road driving.
- A larger 355mm rotor on the rear axle rebalances front-to-rear brake bias, which supports overall stopping stability rather than relying on the front axle alone.
Installation Gallery
Does the TTSPORT SL6 kit fit the Song L DM-i's stock 18-inch wheels without spacers?
What does this Song L DM-i big brake kit include?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.