BMW X5 Big Brake Kit Upgrade / TTSPORT Classic 8703S

This BMW X5 came in for a full four-wheel brake upgrade, and the owner's 21-inch factory wheels made it an easy candidate for a genuinely big kit. The result: a TTSPORT six-piston setup up front and a four-piston setup out back, both tucked behind the stock wheels with room to spare.

The X5 has always leaned on a heavy, high-riding body and a sturdy factory brake package to match. Bumping the rotor diameter and caliper piston count gives the pedal more margin, especially with a full load of passengers and cargo on board — the kind of driving this SUV was built for.

Vehicle & Kit Specs

Side by side, the difference is obvious. Behind the stock brakes, you could see straight through to the dust shield through the wheel spokes. With the TTSPORT rotor and caliper filling that same space, the shield is fully hidden — a quick visual check that the upgrade is sized right for this wheel.

Why It Works

• A forged six-piston caliper up front spreads clamping force over more pad area and flexes less under hard braking than a stock caliper, which is what actually firms up the pedal.
• The 405mm front and 380mm rear drilled rotors carry more mass and surface area than the factory discs, giving the system more heat capacity before fade sets in — useful on a heavy SUV working through repeated stops.
• Both rotor sizes were engineered to clear the owner's 21-inch wheels without spacers, so wheel offset, bearing load, and steering geometry stay as the factory intended.

Installation Gallery

FAQ