Lexus IS300 Big Brake Kit Upgrade / TTSPORT Classic 8657S
A Beijing-based Lexus IS300 owner wanted more braking margin for high-speed driving and occasional track use than the factory brakes could deliver. Instead of chasing a full track-only setup, the owner installed a TTSPORT Classic Series front six-piston / rear four-piston big brake kit — a straightforward OEM+ upgrade built to bolt on without spacers.
The finished setup pairs a TTSPORT 8657S front caliper with a matching TTSPORT 6411 rear caliper — a combination sized to work with the car's factory 19-inch wheels, no spacers or wheel changes required.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | Lexus IS300, 19-inch wheels |
| Front caliper | TTSPORT 8657S forged six-piston caliper |
| Front rotor | TTSPORT 380x34mm high-carbon heat-treated slotted rotor |
| Rear caliper | TTSPORT 6411 cast four-piston caliper |
| Rear rotor | TTSPORT 345x28mm high-carbon heat-treated slotted rotor |
| Bracket | Custom vehicle-specific caliper bracket |
| Pads / lines | TTSPORT high-performance street pads, stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fasteners |
The front caliper used in this build is the TTSPORT 8657S. Its full spec sheet is below.
| Brake Caliper | |
|---|---|
| Series | Classic Series |
| Model / Application | 8657S |
| Axle Position | Front |
| Piston Count | 6-piston |
| Piston Type | Two-piece heat-insulated pistons with dust boots |
| Piston Diameter | 30 mm × 2 / 34 mm × 2 / 38 mm × 2 |
| Caliper Dimensions | L 350 mm × W 165 mm × H 92.64 mm |
| Total Piston Area | 55.0 cm² per caliper, all pistons combined |
| Manufacturing Process | Two-piece forged aluminum body |
| Net Weight | 4.05 kg per caliper, without pads |
| Surface Finish | High-temperature gloss coating |
| Recommended Wheel Size | 18 in or larger |
| Recommended Rotor Size | Ø355–405 mm × 32–34 mm |
| Fitment & Installation | |
| Minimum Spoke Clearance (mm) | 107 |
| 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
The 8657S is a revised version of TTSPORT's earlier 8657 caliper, with a piston layout tuned for more precise brake force control. The more open, vented caliper body improves heat dissipation for sustained high-speed driving, and the caliper's narrower profile was specifically trimmed down for better fitment behind 18-inch wheels and up.
- Six-piston front / four-piston rear layout, matched as a set for balanced front-to-rear brake force distribution
- Larger 380mm front and 345mm rear rotors add rotor mass and surface area versus stock, for more heat capacity under repeated hard stops
- Fits behind the car's factory 19-inch wheels with a vehicle-specific bracket — no spacers required
- Designed as a bolt-on kit for mid-to-large sedans, SUVs, and MPVs, not a track-only, single-application caliper
Installation Gallery
What wheel size does this TTSPORT big brake kit fit on the Lexus IS300?
What's included in the kit?
Is the rear caliper matched to the front for balanced braking?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.