E-man930

I think the centering rings are to ensure no wobble or vibration caused by the rotor not centering itself solely via the studs.

rlm328

If your rotors are wobbling you have other problems. The rotor hat is sandwiched between the wheel and spindle. It is in there pretty snug so wobble it won't. If it is a little off center it does not matter as the rim of the rotor does not rub up against anything. It is not necessary.

E-man930

Wobbling off axis, meaning off center. And yes it does matter because of centrifical forces being uneven and causing vibrations as the rotor spins faster and faster. The Porsche factory designed a bevel on the inside of the rotor hat to locate it perfectly in the center of the 996tt hub. Since the 951 hub is smaller, centering rings are used to fill in the gap and center the rotors the same way Porsche intended.

rlm328

Whatever, as I have said I have never used them and have never had any issues in the years that I have had the 996tt brakes on my car.

E-man930

And a cordial whatever to you too. :/

Darkstar1

And so how did the brake swap go for you E-man?

E-man930

pretty freakin sweet!