Nobody seems to mention the damage that small stones do due to the callipers and wheel barrel small gap. Small stones get caught in between the wheel barrel and caliper causing excessive amount of damage.
These pics are from my 981 GT4 when it was only a couple of months old. I'll never get PCCB again.

 

Oh yes, we mentioned it and there are a number of threads here about it, it can happen as you know, as do I.

But as you know, this is not actually the fault of PCCB rotors, but rather not enough clearance from the Caliper to the inner barrel of the wheel, and FWIW I have only seen this on the front wheels.

 

I don’t think it changes his point. Wider rotors lead to calipers closer to the inside of the wheel. It’s a fair concern and should weigh into any decision, I think.

 

True, except bigger wheels or shallower caliper design (discussed before) could increase these clearances.

Conversely, there are many here that want to go down to 19" wheels for track purposes, this could make the problem worse.

 

Yes correct, not only enough clearance but also the "scoop" design of the clippers, perfect for wedging in stones.

 

@Adrift This is the Tarett kit. Essentially, Porsche caliper bolts are one-time use. So you would need new caliper bolts every time you swap pads or pull the calipers for any reason. There is a risk of cross threading during this process.

The Tarett studs get installed once. Then the caliper nut is all you need to remove. Would also encourage the brake line bracket, also seen in this link.

You just need to verify length of the studs per their sizing spreadsheet based on the car and brakes.

I'd circle back with Hinz to understand if their spacer changes these dimensions at all.

https://www.tarett.com/items/986-987...csk-detail.htm

 

Rick,
Thank you for chirping in. I have a question related to your point number 4 copied below:

Would it be practical to swap in/out your system with the factory PCCBs each season as follows: For the ~10 weeks most likely associated with track day use run your CCSTs, and then swap back to stock PCCBs for low dust operation and routine street driving the rest of the year? (Not needing the spacers is also a plus.) I may just call you for a number on this, but do have an estimate of the component costs associated with such a set-up for a GT4. (~$12k USD?)

 

I had the same occur in just the first few weeks but it isn't a big deal. It is not visible from any normal viewpoint.

You have to get bend down and look well into the wheel barrel to see it. You can't see it on the caliper unless you stick a camera in there or take off the wheel. I only ever notice it when I'm washing the car and it's only on the fronts so far.

 

So the clearances are the same with the 718, seems like Porsche doesn't listen and ignores the issue..
I read somewhere where the groove wore through the barrel creating a leak I'm guessing this would also weaken the strength of the barrel.

 

Although I can feel the 'scratch' in one of my front wheels, it is nowhere deep enough to cause a leak, I would refer to it as cosmetic. Anything deep enough to cause a leak would be scary!

 

It's no where near equivalent to what would happen at a lapping day.

You can youtube videos of people who did the experience as proof of how tame they treat the cars. 1 moderate braking zone, couple smaller braking zones, instructor holding the reins of where everything gets done, out and back in after a few laps type of thing. No helmets is a good indication of how hard they are pushing the cars.

 

@Adrift , great thread and some great info posted throughout.

I don’t mod my cars and am concerned with P car warranties as well my car insurance (in Aus at least, they get VERY particular about modifications from factory).

I'm going for CCBs on my Spyder (pending my build slot coming up soon), she will be a keeper for me and I want factory P car best I can get, so Ceramics it is. I’ll deal with any costs in 5 years if that happens, I’m here for a good time, (likely) not a long time.

Good luck with your decisions.

 

If there was a recurring safety problem with gravel cutting through wheels on the many 911s/Caymans/Boxsters with PCCBs there would be a design change or recall. I tried several attempts at finding a case of an air leak or wheel failure using a variety of Google searches and have yet to find any. If anyone can cite a worrisome number of actual recurring cases of this I'll take the concern more seriously.

 

There would be no benefit to swapping between the OE and ST rotors. Store your OE rotors for resale/trade if you plan to get rid of the car at any point and to use in the event your ST rotors are off for resurfacing.

The ST rotors will have no brake dust. You might consider a pad swap between street/track but once the ST rotors go on the car, no reason to switch back.

 

Aside from this not being all that common, particularly for folks not in snowy climates, do you get down on your hands and knees and look at the inner barrels of your wheels on a regular basis?

IMO worrying about this is like worrying about scratches on the under carriage of your car.