I know the 550/575 and GranSport share the same brakes and the 550/575 brake upgrade from Brembo also fits the GranSport. Now looking at the Quattroporte, which doesn't stop all that well, it appears though in the Sport Package version it uses the same rotors as the GranSport and 550/575. However the brake calipers are different, the QP uses a weird three piece, 4 piston caliper upfront and a two piston Brembo style rear. The 550/575 and GranSport all use Brembo 4pistons front and rear. The reason I mention all this, is that it may be possible to upgrade the QP's brakes to a 355mm(14in) Front and 345mm(13.6in) Brembo kit pretty easily seeing that the rotors and hats should fit. Even though the QP calipers mount in the same location as the 550/575, the GranSports mount on the front side of the hub, but this probably just involves flipping the brakes. Anyone have any ideas. The bottom line is the QP could benefit from bigger brakes.
