Mixing PCCB rotors w/ iron rotors?

[cfjan]

My front PCCB rotors (from my 996 GT3) are being replaced with iron rotors. My question to the group is, do I have to change out the rear as well? The shop that's working on the car wants to change out the rear too (understandably for liability reason, I assume).

Does anyone have experience running front iron rotors w/ rear PCCB rotors?

I mean, there's really no "magic" involved, right? Friction is friction. As long as the rear is not overpowering the front (that would create instability), I don't see how one can't mix the rotors. (If anything, the pad materials would be more critical, as one can run pads w/ higher and lower friction rating to change the bias)

Thoughts?

[W8MM]

I can speculate, but I'm not a brake engineer and I have never played one on TV.

One should be careful about line-pressure and temperature differences in the response of the two rotor materials. I can imagine a situation where the apparent brake balance could shift depending on how many laps had produced what temps. It might be slow and barely noticeable or it might be spooky quick to occur with "meaningful" differences.

Be careful:-8

[TFENT]

Honestly, your best bet is replacing your PCCB rotors with at minimum the MovIt CER Rotors. You kill 2 birds with one stone with the CER replacements. The steels are less expensive initially but will wear out more often and do not give you the durability or performance the 997 demands. The CER's cover all bases and last a lifetime...

[cfjan]

MovIT would be nice but it is out of question, as cost is a major factor here..

On the 996, the rear last a long time (no PSM, so the rear brakes are not used to stabilize the car), so I am not too worry about the durability aspect.. more just that if I don't need to change it, that's more money in the pocket for other stuff..

[mooty]

one of the fastest 6gt3 in CA ran pccb rear with steel fronts.
but if you want to have zero doubts, just run iron rear discs. they are not much $$$.

movit is good stuff, but until it has accumulated "lifetime" use on track, it's all educated "guesses".

[SH || NC]

You can run the ATEs up front and stock cup rotors in the rear for a low cost iron setup.

[AllanJ]

You can run the ATEs up front and stock cup rotors in the rear for a low cost iron setup.
^^^ I do this now.

A while back I pulled my front PCCB due to small cracks forming and replaced with 997 Cup rotors. The front Cup/rear PCCB combo worked fine, no ill effects on the street, autox or track.

[PJS]

Gamroth has done it on a 996 that is very quick