BMW X5 Big Brake Kit Upgrade / TTSPORT Classic 8703S
The BMW X5 was BMW's first four-wheel-drive model and, since its US launch in late 1999, has been a benchmark in the luxury SUV segment. This case car runs the 3.0L turbocharged inline-six good for 306 hp and 400 Nm through an 8-speed automatic — plenty of motor for a mid-size SUV. The catch is the one most heavy SUVs share: curb weight outruns the factory brake hardware. The stock system is adequate for daily driving, but owners who push the X5 harder feel it fade and go soft. This build swaps in a TTSPORT 8703S big brake kit to close that gap.
The install was done by SRW Auto Studio in Hangzhou, fitting the TT8703S caliper and 355x32mm rotor package behind the X5's 18-inch factory wheels — no wheel change required for this case.
Vehicle & Kit Specs
| Item | Specification |
|---|---|
| Vehicle | BMW X5 SUV, 18-inch factory wheels |
| Front caliper | TTSPORT 8703S six-piston, one-piece cast aluminum monobloc |
| Front rotor | TT 355x32mm high-carbon heat-treated drilled rotor |
| Brake lines | TT stainless steel brake lines |
Why It Works
The TT8703S caliper is cast as a single aluminum piece rather than bolted from two halves. That one-piece bridge holds up to clamping loads with less flex than a split-caliper design, which is the difference between a firm pedal and a mushy one under hard, repeated braking.
- Six pistons spread clamping force across a larger pad, giving more consistent bite for a heavy SUV.
- The 355x32mm high-carbon heat-treated rotor carries more thermal mass than the factory disc, resisting the warping that leads to pedal pulsation.
- The drilled rotor face adds friction and helps vent heat, working alongside the caliper to hold performance over repeated stops.
- Stainless steel lines cut hose expansion under pressure, so pedal input translates more directly into clamping force.
Installation Gallery
FAQ
What does the TTSPORT 8703S kit include for the BMW X5?
Will the TT8703S kit fit factory 18-inch wheels on the BMW X5?
How is the TT8703S caliper built, and why does that matter?
Need fitment confirmation? Choose the closest TTSPORT series or send your vehicle, wheel size, and intended use before ordering.