Jaguar XEL Big Brake Kit Upgrade / TTSPORT Classic 8657S
The Jaguar XEL sells on British styling and a sporty character, but its factory brakes don't always back that up. Some owners try to close the gap with caliper covers — plastic shells clamped over the stock single-piston caliper to fake a big-brake look. It's a cosmetic fix for a mechanical problem, and it comes with real downsides.
This XEL owner skipped the cover and went straight to a functional upgrade: a TTSPORT Classic Series 8657S six-piston caliper kit paired with a 380mm rotor, running behind the car's stock 19-inch wheels.
The Caliper Cover Trap
Caliper covers clip or bolt onto the outside of the stock caliper. They don't touch the hydraulic system, the piston, or the pad — they're purely visual. That creates three practical problems:
- They're not always securely mounted, and can loosen or come off under hard braking or at highway speed.
- They add no cooling capacity, so the underlying caliper and rotor still overheat the same way, leading to the same fade under sustained braking.
- They don't change piston count, pad area, or rotor mass — stopping distance stays exactly where it was.
Vehicle & Kit Specs
Here's the hardware breakdown for this Jaguar XEL build:
| Item | Specification |
|---|---|
| Vehicle | Jaguar XEL, 19-inch factory wheels |
| Front caliper | TTSPORT 8657S forged six-piston caliper |
| Front rotor | TTSPORT 380mm high-carbon rotor |
| Bracket | Custom vehicle-specific caliper bracket |
| Pads / lines | TTSPORT high-performance brake pads, TTSPORT stainless steel brake lines |
| Hardware | Brake fluid, mounting bolts, and fastening hardware |
Below is the full TTSPORT 8657S spec sheet for the caliper used in this kit:
| 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 two-piece forged aluminum caliper, not a floating single-piston unit. A rigid, fixed body flexes less under load, so pedal input translates into clamping force more directly — the "vague" feel of a stock caliper largely comes from body flex, not pad material.
- Six pistons in a progressive layout (30mm/34mm/38mm pairs) spread clamping force more evenly across the pad, which is what gives the linear, controllable pedal feel TTSPORT describes for this caliper.
- Two-piece heat-insulated pistons with dust boots handle sustained heat better than stock pistons, which matters most on repeated hard stops where OEM brakes start to fade.
- A vehicle-specific bracket is engineered around the XEL's factory 19-inch wheel geometry, so the kit clears the stock wheel with no spacers required.
Installation Gallery
Does the TTSPORT 8657S big brake kit fit the Jaguar XEL's factory 19-inch wheels?
What rotor size does the Jaguar XEL use with the 8657S caliper?
What's included in this Jaguar XEL big brake kit?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.