RacingBrake

What we have observed from tracking down Russ' Z28 in different events* can confirm the transfer of material is a very fine/thin layer (after smooth out those rough surface), which is replenished as the pad wears down. Note from my previous post the friction force for CCM brake is via the layer between the disc and pad. (unlike traditional iron rotor directly with the pad.)

You can expect the brake dust would work just like the original CCM rotors (literately no dust).

So far our tests (street and track) are on CCM rotors supplied by Brembo for ZR1/Z28 only, no pccb rotor yet, which will be our next project.

* Micrometer was used to measure the rotor thickness change, and thickness variation after each event.

dewilmoth

I am under the impression that weight dictates wear level on a carbon rotor, not thickness. My ACR rotors are marked with a minimum weight in grams, and I vaguely remember the same on my PCCB Turbo. So if that's the case, how does the pad transfer have any bearing on extending the service life of the rotor? Sure, it makes the rotor thicker, which seems irrelevant when the rotor wear is gauged by weight. It also adds mass to the rotor surface because of pad transfer, which I'm guessing plays into your argument of the rotor not wearing, but that argument seems a little iffy. How do you know the minimum weight of the rotor now that you're putting extra foreign material on the surface. It seems to me that the foreign material on the surface would do zero to help the structural internal makeup of the rotor which has been cooked already due to heavy use. So yeah, it might take longer to get to the indicted minimum weight printed on the rotor hat, but that minimum weight was predicated on a different pad that wasn't transferring material, so what's the actual minimum weight now? I'm guessing it would take a major cash outlay to have an engineering firm come up with the answer to that question.

RacingBrake

Damage to CCM rotor was due to oxidization (over-heat), not wear, as I said earlier because the rotor is extremely hard, so no brake pad can possibly wear the rotor down.



When your rotor has a rough surface (high and low spots) like that if you check rotor thickness it will still be within specs, because the instrument contact is on high spots only.

At this point, you will feel vibration lost of braking power and the pad wear will accelerate, down to backing plate like those shown in earlier post on Ferrari Speciale.



This is when the sintered pad can work its way to heal the wound and restore the disc surface to a smooth surface.

It's the best if a sintered pad is used when the rotor is new (before start pitting) and transfer a layer to rotor surface which can preserve the life both on brake pad and rotor.

RacingBrake

There are different way of determine the rotor's life or serviceability including weight check, wearing mark which are suggested by OE.





This is the guideline set by OEM and they expect you to observe and follow as recommended. However you will not disagree those drilled holes are quickly filled with brake debris, randomly full or partial (see below) which contribute to the weight of rotor, but I have not seen any mentioning of the weight factor attributed to the drilled holes, so I wonder how reliable the weight method is.



Our method is the old school way (same as recommended by Surface Transforms) that is disregard the weight and observe the condition of rotor surface, yes theoretically the layer will add weight to rotor but its only a thin film the weight change is negligible, nor it bears any significance if you agree #2 (below) is a better way.

So basically you have two options to decide when to replace the rotor:

1. Follow OE's WEIGHT method, which you might want to clarify with dealer how to factor in those drill holes build up to be more accurate.

2. Use RB's SURFACE CHECK method and disregard the weight factor.

I think both would work, just a matter of which method is easier, quicker, more practical, and cost effective to determine the serviceability of your CCM rotor - It's entirely up to you.

RacingBrake

RB CCM brake kit installed on a 991 TurboS (18" wheels). Calipers are equipped with sintered track pads.

qbix

I love this thread! It resembles a black hole.

That sucks in all naive uneducated morons from this forum. They will soon be out of the streets crying loud over their bill.

orthojoe

LOL. This is a zombie thread that just won't die.

GTR GUY IN AZ

Wow............. Warren at RB does a great job for all cars. I currently have a GTR and my son has a GT-3--- 2015. He can't quiet run the lap times I can but his car does brake much better. I just spent 90 minute at Porsche's west coast experience center in a GT-3 and again ..GREAT CAR.
Consider Warren's brakes as an option rather than just blow off the RB results.
We don't run CCR on the GT-3, we run steel because Porsche CCR's are too expensive to replace after 10 track days and ....................We flip the cars every 2 years ..........

RacingBrake

What they said:

Brakes are critical on any vehicle but get extra attention on track-focused cars.

At Pikes Peak they get double-extra importance. Not only because you're barreling towards a drop-off at any one of the course's 150+ turns, but because speed management is constant and frequent.

Earlierapex

a) you state that ceramic rotors "wear" due to heat, not friction.
b) your magic pads repair the rotor with a thin deposit of pad, which you admit is actually exactly how every other ceramic pad works.
c) you claim extended life of the rotor due to the reduced exposure to friction forces (which are now being applied to the transferred pad layer).

So which is it that wears the ceramic rotor, heat or friction? I guess it's heat with the stock pad then it magically becomes friction with RB pads?

RacingBrake

a) CCM rotors would hardly wear. No brake pad of any kind can wear the CCM rotors like it would on iron rotors. CCM rotors are subject to deteriorating (surface pitting) due to the overheat (oxidation).

b) Same "deposit" but different result, RB sintered pad is 100% metallic (no resin) the deposit is consistent and uniform across the rotor surface which is beneficial and protective while the conventional semi-metallic pads use resin to hold the friction ingredients together. As the braking temperature goes up resin got melt and emit an inconsistent deposit on rotor surface which is harmful.

c) Yes, a good layer of pad transfer between a CCM rotor surface and brake pad is the way to assure a successful run on CCM brakes.

We never called it a "magic" pad, the sintering (powder metallurgy) is not a new technology, rather we used it to formulate and make a brake pad* to deal with CCM brakes based on our knowledge and expertise.

In RacingBrake all brake products are designed and made with good understanding of metallurgy and fundamental in materiel science.

There is no magic, nor we believe there is one. In our terms a brake issue is usually explainable with a possible solution. It's a proven product that has undergone more than 2 years' development and tests before release. It's relatively new to Porsche but not to other heavily tracked communities such as GTR, ZR1, and Z28.

* Comparing the conventional semi-metallic, the Coefficient of Friction (COF) is considerably higher ~(0.65 vs. 0.5), and more consistent (stable) in friction level w/o being affected by the braking temperature.

Warren-RB

CAlexio

Warren, would you recommend immediately switching to a metallic sintered pad then even with new ceramic rotors so as to create the deposit right away and protect the ceramic disk from any wear? I understand the skepticism to what you are saying, but I also believe you could be absolutely correct. I'm open minded and looking for info. This could be a game changer

17bhub

+1

RacingBrake

Yes, the sooner the better. Why? because as stated earlier, the method of friction between ceramic discs and pads work differently than iron discs.

With iron discs it is the friction between the disc surface and the pad surface that provides the braking force, but with ceramic discs it is the friction between the pad material that has been laid onto the disc surface (Transfer of Layer) and the pad itself that is what provides the braking force. Once the sintered pad layer transfer is completed the disc is protected by the layer, as the layer wear off it's immediately made up by the sintered pad, so this cycle repeats until the pad is worn out and replaced.

We also believe a more practical way to determine CCM rotor's serviceability is to inspect the rotor surface - If it appears smooth and shining it would indicate the disc is healthy, or pitted/rough/delaminated that shall tell you the disc has oxidized or when the disc is loosing its weight in OE/dealer's method (by weight measurement).

Let me repeat that due to its super hard surface, a CCM rotor will never wear down like iron rotor, there is absolutely no brake pad of any kind can possibly cause wear to a CCM rotor. Conversely if a CCM rotor is deteriorated with a rough surface it acts like a grinder and would wear the conventional semi-metallic brake pad down like no time.

It's not uncommon a CCM track pad can turn into dust in just a few laps, and wear down to backing plate.

On Ferrari:


On GTR:


If a CCM rotor already started deteriorating (w/pitted surface), RB sintered pad still can amend it but the pad will wear out faster. So may be the thread title should say "...at the cost of pad wear" at this stage of discussion.

Warren-RB

W8MM

Warren,

You are to be commended for keeping an even keel responding to so many insulting and superstitiously ill-informed taunts. I feel your pain.

I have been chasing more durability in CCM brakes since I put Surface Transform rotors on my former Carrera GT a decade ago.

I had the occasion to speak with a VP of engineering at Weissach when touring the long-lead intro for the 918 in August of 2011. He thoroughly explained the failure mechanism of PCCB rotors to me in the same way you have tried to explain it to Rennlisters. Your explanation agrees 100% with what he told me about over-temp causing the carbon fibers to "burn" (oxidize) and the "worm hole" voids left in the surface (pitting). His English was very good and I understood him exactly.

I have had very good luck with Surface Transform rotors and can only imagine there are even better rotor construction possibilities now or in the future.

I have one remaining question about the sintered metallic pads: When they build up a metal layer (micro foil?) on the CCM rotor, how does that modify the oxidizing-from-heat failure mechanism of the underlying CCM material? I can see how copper could be a heat spreader to equalize impending hot spots, but is there more to it?

BTW for onlookers, I am a 25+ year member of the Society of Automotive Engineers ;~}