DK7

Hi guys,

my rotors have some crackes.
Do you think i should use the brake even longer? How much further life is possible..?
Thanks.

ilko

Rotors are toast. Cracks are bad (but OK for a few more miles of street driving). The bigger problem is the large lip at the outer edge of the rotor. It means that the rotor is likely below minimum thickness at this point. Pads look OK.

DK7

Thank you. A pity. I thought I can do 2-3 trackdays...
The lip at the outer edge of the rotor "looks" on the picture a little bit more than real.

boostedt0y

Yep looks toast to me. I have some OEM rotors with less than 3k miles I'd sell cheap. If interested PM me.

rbahr

I guess I am gonna take a contrarian view here. Those small heat check cracks are fine - it is when the cracks make it to the edge of the disk that they are officially junk... I run stuff like this all the time and have yet to have a problem.

Ray

boostedt0y

The cracks are fine. As you mentioned, its when the cracks make it to the edge of the rotor is when they are really a problem.

The issue with OP rotors is not the cracks, but that the rotor is likely below minimum thickness due to the significant "lippage" on the rotor. Best way to confirm is to grab a caliper and measure rotor thickness.

Fisher

A bit of preventative maintenance could be used to reduce the rotor deterioration. Cleaning the holes is a start.

I have been told the following:
"The drilled holes on a brake rotor make it easier for heat, gas and water to be moved away from the rotor surface, helping to keep the brake performance strong."

Dr.Porsche

I'll chime in here as well. Cracks are fine. Can't tell about the lip, but the cracks are not a concern unless they go to the edge or connect the dots.

ranger22

Rotors look fine me to. You can have many more track days out of those.

AGO

I've driven with that rotor condition at the end of their life when I was starting. I'd suggest if tracking to be mindful of brake requirements of the specific track you would run, and also related to your speed/run group...

In you are in doubt, swap them ... those rotors have given plenty of track fun !

rbahr

As far as the lip - I thought I saw one - was not sure - just measure it...

I generally will go with slots over holes anytime - brakes are all about thermal mass, the more the better...

Anyway @ 400-500 deg f water does not last long in a liquid state, current pads don't really outgass much (after they are bedded in), the rumor is that the real Porsche rotors are cast with the holes as opposed to drilled - helps with internal stress...

So, if the rotor measures ok, pads are ok, you still have life - BUT keep an eye on the cracks ...

Ray

DK7

Here you can say the outer edge better.

DK7

..

rbahr

Those are getting a bit worn and I would measure them, but it still looks like there is life in them esp if this is primarily for street use.

Ray

Rob996

For those wanting an idea of totally toasted rotors.