The Definitive Z34 Brake Resource

Solus

Forgive my ignorance but I have one of the ever famous stupid questions. Although I can tell the difference between a 1 piece and 2 piece rotor. What is the performance gain of 2 piece of 1 piece? Why is it "better"?

wishihadnav

less rotational mass.

ChrisSlicks

In addition to the "less rotating mass" it also means less unsprung weight. The 2-piece front rotors are more than 10 pounds lighter per corner on average.

2-piece rotors have an aluminum hat (preferably billet) and a iron ring. They can be bolted together in different ways, either fixed mounts or full floating mounts. The full floating setup allows for a larger temperature differential between the ring and the hat as it allows for more expansion, however it requires more maintenance, it is typically only applied in racing setups. The fixed mount setup can move as well because the 2 metals will expand at different rates, however their movement is limited by design.

2-piece rotors in the rear application may use an iron hat in order to have a more durable e-brake functionality. If you are only using the e-brake as a parking brake an aluminum hat is perfectly acceptable provided an appropriate thickness is used.

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Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms

Scott @ RA

^^ Nice post and a perfect explanation.

markymark

great thread : )

anyone have any experience with the carbotech bobcats? I'm after a semi street/track pad but didnt want the squeeling of the carbotech xp's/hawk hp+

ChrisSlicks

The Bobcat's do well on the street and auto-x but will wear down to nothing on the track in a day. A friend of my with a Corvette Z06 tried them on the track and found out the hard way by wearing them down to the backing plates and damaging his calipers. He is an older guy and fairly conservative driver.

__________________
Hotchkis ARB | Stillen CAI | Art Pipes | Berk CBE | Stillen AP Racing Brakes | AE Performance Oil Cooler | BC Racing ER Coilovers | Doran Control Arms