mark kibort

anyone know where i can get some? Rumor has it, that someone found some a while ago. (or 964Turbo rotors 1991)

Thanks,

Mark

svp928

Mark, if you can find solid rotors, I will cut the slots for you...I can also have them cryo'd...

Steve

mark kibort

Thanks Steve!

do you think that it is safe to cut slots in the solid rotors. It doesnt have the same issues as cutting holes into a rotor that should be cast with them,right?

do we need to make a production run to get scotty, the cool adapters that you can make to bolt on S4 or GTS calipers? If so, we might want to start getting names on a list for his next brake replacement. looks like there might be too much cost associated wtih it right now for him to get the used GTS brakes for sale on the list. (i.e, calipers, rotors, and street pads he wouldnt be able to use as well as additional new brake lines required )

Mark

RyanPerrella

what, did you get sick of those rust rings and decide you needed to change rotors already LOL

svp928

Mark, cutting slots doesn't affect the rotor strength at all- Its fairly easy...
If you can find a few people who might want hats, I would do a run of 10 pcs for a reasonable rate- keep in mind, this conversion uses a bracket that bolts onto the 81-86.5 spindle to allow these hats and rotors to fit. I don't think any off-the-shelf rotor/hat combo will give the correct spacing. However, the hat for the 87 and newer replaces the stock rotor directly.

ROG100

GTS Rotors from Porsche are solid - no slots or holes.

IcemanG17

Steve
I'd be interested in some slotted-cyro GTS rotors.....put me on the list

RyanPerrella

hmmm, yeah i guess the 965 rotors which are cast holed can crack, if your into slotted and want factory quality you get the GTS rotors and cut them i guess.

Whats that slotting cost to do on rotors?

When you do your "Cryo" do you cycle it and freeze and then heat and then freeze again? Or is it just frozen once? Not everyones "Cryo" is the same and from what ive read, if done correctly you can change the molecular structure of the iron which is what gives you the increased wear resistance which is why people do this on high wear items, like brake rotors.

mark kibort

Do you see any rust rings??? ha ha ha
So yes, the 964 rotors can crack

mark kibort

I see. The adapters fit the special offset for the hats you have. And, you have special hats that equate to the GTS offset.

Lets try and do the slots. that would be interesting to try, and probably will be just as good as holes, right?

Thanks Steve!

Mark

RyanPerrella

EEEEHHHH YIKES

WOW Thats telling I think the GTS rotors are in order, or something even larger. I cant say ive seen the cracking THAT BAD, and you cant have that many miles on them. Albeit they are VERY VERY HARD MILES.

oh yeah and no rust rings, but i do see a pristine 15% of rotor surface thats totally untouched!

9x8

It really looks like thermal damage, and IMHO that happens due to insufficient cooling, which is probably caused by the front splitter. Stock front spoiler has ducts that provide airflow to brakes, and by installing low front splitter, you pretty much restrict airflow to them.

I don't really have much practical expirience, so I definitely can be wrong.

mark kibort

I usually get one or two cracks that finally meet the outside edge after many more races and all the other holes have little cracks at that point too.

By the way, 15% of the rotor is untouched, not UNLIKE any other pro prepared car. even the 2 piece rotors look like this when you cruise the paddock and look at the big boy set ups. (not all, but many) . again, the F50 calipers have the same swept area depth on the rotor. the GTS width is unusual, and not seen at the track. most rotors have a narrow path in racing set ups.

Here are a couple examples. I dont have pics from the track, but the real large rotors, 2 piece have even more of an "untouched" rotor area than I do.

mk

cobalt

Wow I do tech for many events and that is the worst case of cracking I have ever seen. Usually you warp your rotors long before that occurs.

What do you need to do to crack a rotor like that? My C2 has big reds with 965 rotors and the car is a dual driver car. I actually out brake the ABS and tires and heat them up quite good with my wife driving after me. Wonder if her driving at a slower rate and far easier braking has helped prolong my rotors. But these are mine after 7k track miles using pagid yellows. They are at their wear limits and need to be replaced.

Is it possible that all the cracking comes from cooling down the brakes properly after a hard run?

Edit:

looking at the picture of the cracked rotor, is that a 928? If so is this the leading or trailing side of the rotor. I am just speculating but it looks like I see drop links which would make it the trailing and that would mean these rotors are installed facing the wrong way. The cooling veins would be going in the wrong direction for proper cooling. I would be curious to know if that is the case.

heinrich

I have 2 sets of drilled 964 rotors I bought from Cobalt years ago Mark ... Not sure if you can use them?