IPSA

yep

GrantG

If not the heat shields or engine as mentioned above, I wonder if the parking brake mechanism could interfere (just thinking of differences between front and rear)?

stout

Thanks for the above, and as someone who just took delivery of a 991.2 with PCCB, I am curious what it would cost—even roughly—to convert to RB CCB with RSL-29 pads. I also suspect it would be my first choice in the event I have to replace my rotors, and would be good to learn more about it. Also like the J-hook option from Essex for track work. While I would be sorry to lose the advantages of CCB, it's great to have options...

Thanks to both vendors for posting!

AutoQuest Motorsports

There is another Carbon Ceramic alternative to the typical PCCB or Brembo ceramics on the market now, the same used by Koenigsegg, Singer and very unique high performance applications like the NIO EP9 and upcoming Aston Martin Valkyrie. Surface Transforms ceramic rotors are much more cost-effective and better performing than the PCCB/Brembo ceramics while maintaining the advantages of ceramics over steels. Due to their unique manufacturing process the Surface Transforms ceramics limit the carbon oxidation to the face of the rotor, allowing for them to be Refurbishable (up to 4-5 times) while maintaining their structural integrity. This is unlike the PCCB/Brembo ceramics which oxidize the carbon content from the entire rotor losing structural integrity over their lifespan, not allowing them to be safely refurbished when the friction layer wears out. As Surface Transform ceramics last the same if not longer than the PCCB/Brembo and each refurbishment resets the wear life, their life expectancy is 4-5 times longer than that of the PCCB/Brembo ceramics. Additional benefits on the ST rotors are as follows below.

• Average of 50% less expensive than PCCB Rotors ($11,998 complete set)
• 3x the heat conductivity and faster heat dispersion
• Operating temperatures approximately 200 degrees lower than PCCBs
• Noticeably reduced brake pad wear
• 50% less weight compared to the equivalent GT3/GT4 steel brake systems (average savings of 45-50lbs of unsprung weight!)

Petevb

Can you please clarify? Compared to what, and how do you figure?

That is a tough to understand statement if you're comparing apples to apples.

CAlexio

Just for clarification purposes.. the Surface Transforms which Autoquest sells, and the Racingbrake option are the same type of rotor correct? I'm having a difficult time distinguishing between the two. It seems that both are refurbishable, and furthermore, RB advertises that with metallic sintered brake pads the system is actually "restorative" as the metal gets re-deposited onto the rotor.

I realize each brand/vendor is interested in maintaining distinguishing features, and it seems that RB also sells calipers which are lighter than stock and easier for brake pad changes.. but if anyone has better clarity on the distinctions it would be awesome. Can you mix and match brands?? Who is using what?

I went with steel rotors from stock, knowing that I was ok with spending approx. the same $9k or so to change to CCM type rotors aftermarket vs getting the yellow caliper pccb from porsche. I'm now working to understand which specific CCM rotor option i need to go with after taking delivery. I'm attracted to the 45-50lb weight savings most of all as I know that will make a massive handling difference, but also the no-brake dust feature.

My only certainty is that CCM > PCCB.. after that.. it's all a bit murky.

I'm sure each vendor might not like this.. but if someone puts together a pro-con chart of the brake vendors, (also vs pccb).. i think one of the most confusing aftermarket segments could get cleared up for me as well as for others who undoubtedly have some of the same questions.

RacingBrake

The real challenge to run CCB the longevity and cost which translated into searching for a proper brake pad material that can truly handle the "higher" brake temperature (~30% than conventional iron rotor), especially for track/racing applications where the pad can wear out very fast under the extreme heat, resulting overheated rotor and causing loss of carbon and rotor surface becomes pitted.

Once rotor surface is pitted, the rotor would act like a super grinder and can grind the pad quickly down to the steel backing plate and ruin the rotor which we see all the time, resulting $6,000/rotor replacement, so conventional wisdom of "buy pccb but converted to iron" and shelf the ccb for future re-sale is understandable. Endless debate whether to "pccb" or not to "pccb" is also expected.

I have spent more than two years in developing sintered (full metallic) brake pads specifically for CCM rotors. It has been successfully deployed on those super muscle cars that are heavy and fast like Nissan GTR, Corvette ZR1, Camaro Z28, Mustang GT350, and Hellcat (both are converting to RB CCM rotors), notably Hellcat is a 700HP 5,800 lbs beast and run @158 MPH (w/XC-41 pad), and David Donohu's 991 Turbo run on Pikes Peak Racing.

Based on our long term observation, we can conclude that a CCM rotor if used with RB sintered pads, the rotor will never wear nor pitted. No need to learn how to measure and interpret the loss of carbon (which can't be accurate anyway unless you also take those "rotor holes plugged with debris" into account), unless you find it's fun to learn something new.

All you have to do is to observe the pad wear and have them replaced at about 1/3 -1/4 of lining thickness. It's also noticed that RB sintered pads last 2-3 times (observed & recorded) longer than conventional semi-metallic pads including ZR1 OE (Brembo), Pagid RSL/RSC, or Endless W007/8) made for CCM rotors.

RacingBrake

RacingBrake is totally independent from Surface Transforms, we only use their discs (just like we use Brembo discs) to build our CCB brake system. ST used to supply discs to us just like they did for Move-It, AP or Alcon, but lately they seemed to have changed their policy to sell only rotor with hats (assembly) through their distributors.

During our experiment in restoring the damaged surface on ST's rotors (continuous/long fiber), we have found that restoration is more difficult than Brembo's chopped fiber. See our posting here.
https://rennlist.com/forums/991-gt3-...l#post14357406

Earlierapex

John, if the operating temps are 200 degrees lower on average, I assume the ST rotors are heavier than PCCBs? What is the weight of each?

Thank you.

Earlierapex

RB, don't carbon rotors oxidize from heat? How does the RB sintered pad reduce rotor heat? Can you please provide data on average rotor temp under controlled conditions with your pad vs. stock?

Thank you!

AutoQuest Motorsports

Brembo and SGL (manufacturer of PCCB rotors) use a similar manufacturing process that provides an end product consisting of discontinuous (chopped) carbon fiber that is held together by a silicon resin. You can see this process by following this link. This manufacturing process leaves these rotors limited to the thermal conductivity of the material itself.

It takes Three Months from start to finish to make a Surface Transforms carbon ceramic rotor. You can review this process on their website here.

ST rotors use a CVI (chemical vaper infiltration) process that is a way of growing a particular type of carbon that is highly ordered and has a much higher level of conductivity. They also use a heat treatment process that increases that conductivity further. This allows for thermal conductivity of ST rotors that are 3x higher than that of Brembo and SGL. Given all the rotors heat up at the same rate to the same temperature, during the cooldown phase the ST rotors are able to dissipate heat away from the surface and through the vent holes 3x faster than the others. Because of this, the ST rotors run an average of 150 degrees celsius cooler than that of the other manufacturers.

ST also applies a liquid solution which attaches to the carbon atoms to stop the carbon from oxidizing at high temperatures, which protects the disc from wear at the higher temperatures seen in track conditions leading to improved rotor life over Bremdo/SGL. These same reasons also lead to a substantial increase in pad life due to the difference in building the friction layer on the rotor material. Conventional ceramic rotors need to use a significant amount of pad material to create a thick friction layer, while the ST rotors already have a base layer in place that uses minimal pad material and less of a severe bedding process to create the usable friction layer between the pad and rotor.

We also believe it is Crucial to understand that although it may be possible for typical Brembo/SGL(PCCB) carbon ceramic rotors to be resurfaced, the structural integrity cannot be replenished as the rotor oxidizes carbon from use. If a typical carbon rotor weighs in out of spec for carbon content, that rotor cannot be reused or resurfaced safely by any method for continued use. This ability to negate carbon oxidation and allow for safe refurbishment and continued use is what sets the Surface Transforms rotors apart from the conventional carbon ceramic solutions.

AutoQuest Motorsports

Given the same rotor dimension and the same scale they have shown in the past to be within ounces of each other. Holding them in each hand you would not feel a difference : )

AutoQuest Motorsports

Nice chatting with you again my friend, and glad I could help clear up some of the uncertainties for you : )

Petevb

You've misunderstood. If you talk with ST I think they will set you straight.

Three times the thermal conductivity does not mean three times the heat dissipation. If you were transferring thermal energy to a solid heat sink that would be roughly correct. Here, however, you're transferring thermal energy to air. This transfer is dominated by temperature and the convection coefficient between the air and the rotor. High thermal conductivity only serves to keep the center of the rotor at close to the same temperature as the surface. In a vented rotor this distance is very small, however, on the order of mm, so even with a poor thermal conductor you're only going to get a very small temperature difference between those two points (and a huge difference between the rotor and the air). Thus even a perfect thermal conductor would only increase the surface temperature of the rotor a tiny percent, and hence increase the rate of cooling a similar percent as the rate of cooling is linear with delta T for air (temperature to the 4th power for radiative cooling, but radiation is a very small percent of heat rejection in brake rotors).

As a sanity check consider that aluminum is still used as a brake rotor material for some applications. It has a thermal conductivity four times that of cast iron; those rotors don't cool four times faster.

Ceramic rotors do cool faster overall, but that's a function of their larger surface area, especially for a given weight, and the ability to run hotter without losing performance and hence increase delta T. Where high thermal conductivity in a brake rotor's really going to help is in keeping thermal stress down, as the surface and interior of the disk won't be at significantly different temperatures during rapid heating and hence won't try to warp/ fracture due to differential thermal expansion.

TRAKCAR