Cadillac CT4 Big Brake Kit Upgrade / TTSPORT Classic 8703

A Cadillac CT4 is built to carry itself like a proper sport sedan, but the factory brake package underneath doesn't always back that up once you start pushing the car. This build swaps in a TTSPORT TT8703 forged six-piston caliper paired with a 355x32mm high-carbon rotor, running behind the car's 19-inch wheels with no fitment drama.

The finished car is running the TT8703 caliper in the brand's fluorescent green finish, paired with the 355x32mm fish-bone slotted rotor and a TTSPORT stainless steel brake line — a straightforward one-axle upgrade over the stock hardware.

Vehicle & Kit Specs

Why It Works

• The TT8703 is a forged monobloc caliper rather than a two-piece bolted unit — a solid forged body flexes less under hard pedal pressure, which means more of your pedal input goes into clamping the rotor instead of stretching caliper halves apart.
• A 355x32mm rotor carries more mass and surface area than the stock disc, giving it a larger heat sink to work with when the pads are loaded up repeatedly — that translates to more resistance to fade on a track day or a mountain descent.
• The fish-bone slot pattern on the rotor face is there to move dust and outgassed material away from the pad contact area during hard use, while also adding mechanical strength to the rotor compared to a plain face under the same extreme conditions.
• The kit was fitted and photographed running the CT4's factory 19-inch wheels, confirming the caliper and rotor package clears the wheel without a spacer.

Installation Gallery

FAQ