BMW M3 (E9X) Big Brake Kit Upgrade / TTSPORT Classic 8703S

This BMW M3 isn't a standard 3 Series under the skin — roughly 80% of its parts are M-specific, right down to the naturally aspirated 4.0L V8 that broke from BMW's usual inline-six formula. A car built to this spec deserves brakes that can match the engine's character, so the owner went with a full front-and-rear TTSPORT swap instead of a front-only patch job.

The car runs a 4.0L V8, which means more mass to slow down and more heat to manage than the inline-six M3 variants. Upgrading both axles at once — rather than just the front — keeps braking balance consistent under hard use instead of overloading a stock rear setup paired with a bigger front.

Vehicle & Kit Specs

Up front is the TT8703S, a street/track dual-purpose caliper paired with the 355mm rotor. The larger rotor diameter fills the wheel opening more fully and gives the pads more contact area to work with. The curved-vane pattern isn't just cosmetic — it helps sweep debris off the rotor face while the vanes move air through for cooling.

Why It Works

• Front six-piston TT8703S caliper spreads clamping force across a bigger pad area for a firmer, more consistent pedal.
• Larger 355mm front / 345mm rear rotors add rotational mass and surface area, which means more heat capacity before fade sets in.
• The full kit was fitted and confirmed to clear the car's 19-inch wheels.
• Upgrading both axles together — not just the front — keeps front/rear brake balance matched instead of shifting bias too far forward.
• The rear TT6411 four-piston caliper is compact but, paired with the M3's chassis, still delivers meaningful rear stopping force alongside the upgraded front.

Street/track dual-purpose calipers like the TT8703S are built to handle repeated hard stops without the fade you'd get chasing this kind of performance out of the factory setup — useful for a car whose whole point is being driven hard.

Installation Gallery