CobaltCr

Um no it doesn't. It presents them as a way to restore your ccm rotors. Says so in the title. If you mean something else from what the title says you should change the title. You would have less controversy then.

RacingBrake

https://rennlist.com/forums/991-turb...ikes-peak.html





https://rennlist.com/forums/991-turb...ak-record.html

DDonohue

Sorry for such a stupid long post. If you have insomnia, here is a cure…

I am long overdue to post here, especially after Warren was so helpful at such a critical time in our program. My observations are the result of my actual use of the RB friction materials (CCM Discs and Sintered Pads) and calipers. I would add that I have extensive experience with PCCBs through multiple generations because of my work with Porsche. I work for Porsche currently, but this is not a Porsche influenced write-up. Personally, I love the PCCBs and wouldn’t buy a car without them. Their performance advantage is without question.

To Begin - the Pikes Peak car started life as a well-equipped 2014 Turbo S, including Burmester and a load of other options. If you are going to ask why start with that car, then you can stop reading now because logic doesn't apply to motorsports...ever.

I admit that I do not know in depth all the science behind the materials used, but I have a lot of experience with a broad selection of traditional brake arrangements through my racing and testing. This includes carbon materials on the GT2 Viper back in the late 90's, the Panoz LMP-900, the IROC cars, and the RS Spyder. In the DPs, after much testing, we would change pad materials based upon track grip level, downforce level, ambient temperatures, and race duration. We used a variety of materials from different manufacturers, and would even mix them front to rear based upon conditions, results, and feedback. It cost A LOT!

The most important statement I can make here is that the RB supplied materials and calipers worked flawlessly from the beginning. The braking was consistent from the moment we began testing throughout the course of the month, and until the very end. Even throughout the brake zones themselves, I found little variation from initial bite until the release. We had some challenges with bleeding as you always do with a newly installed system. I found that the best method was the old-fashioned manual pump and open technique, which was superior to vacuum or pressure methods. This was after some good use and heat cycling. Once we got the air out, it was really good and confident.

We are making changes to the car for next year, but the only change to the brake set-up will be Bosch ABS and dual masters. The RB pieces will remain for sure.

To pre-answer questions – here are some random notes. I have a whole lot on my plate right now with Porsche (Thanks to GT3, GT2 RS, and Turbo Exclusive). I really don’t have time to answer questions here, especially if they are confrontational.

Note 1 - Given the competition on the mountain it became very clear we needed to fit 18" wheels in order to broaden the tire selection and availability. Because the stock front discs are 410mm (~16"), they could not be retained within an 18" wheel. We already had a rather heavy car (400+ lbs heavier than the winning car), and the brake weight is an often-overlooked performance area. The weight savings in the brakes is an easy acceleration/deceleration and handling advantage with the only downside being the initial cost. Because there were suspension interferences, many changes in the rear also had to be made in order to fit the wheels.

Note 2 - I didn't want to use a full carbon brake because I could not afford to wait for any warm-up time for the materials to begin working. The brakes needed to work immediately and consistently at any temperature. At Pikes Peak, the ambient temps can vary from the mid 80's to the 30's. In spite of cool temperatures, at 9500-14,000 feet, nothing cools like you would hope. For Example, my Macan would normally run 230-260F degree oil temp when running at 25-30 mph up the mountain...and even back down.

Note 3 - We considered using 997 PCCB materials, but they are of an older generation and still rather expensive. RB was able to supply everything we needed, and was one of the few bits that simply bolted on with no modification whatsoever. The only thing we could have done was add a ~3mm spacer to the front caliper to move it outboard a little, but we had much more critical items to attend to all month. The brakes (Friction materials and calipers) worked flawlessly from the beginning and were never a concern.

Note 4 - It is important to understand that the RB discs and the PCCB Discs are quite different in spite of both being Carbon Ceramic. The PCCBs are only about 3% carbon. The PCCBs are checked for wear by using a special tool from Porsche that measures the remaining carbon content in the disc. There is a clear visual difference when you see the two discs side by side. The PCCBs have a more crystal like appearance when looking at the "end-grain" where a traditional iron brake would have its vanes. In contrast, the RB disc looks much more like a traditional carbon disc in this same area. However, the radial surface where the pad makes contact (disc face), both discs look very similar when new on this disc face. With the RB materials, this new look doesn't last long (see note 7).

Note 5 - I will say that the materials we used were a bit loud, not squealing, but more like a low level grind. You can hear it slightly in the videos from the in-car. This is perfectly acceptable and not noticeable for a race/track car, but it would drive me nuts on a road car. Warren told me this is a characteristic of this material and there are others that do not sound like this.

Note 6 – Issues – A) We had some issues with the brakes only because we were using very soft/low temp racing slicks and the stock boosted brake system and ABS. If I went very quickly to the pedal (because you can with slicks) I would occasionally get an uncharacteristically hard pedal that would throw me off. B) We tested at ~6500 feet at a few local tracks when it was 80-90F ambient, and some of the uninsulated sensors/wires melted in the heat. C) We had an ABS wire get cut on a wheel weight in qualifying which is why we qualified so poorly. Also of note, we did not add any brake cooling, not even for testing. However, in testing, we did end up putting blower fans at the wheels when I came in for changes to reduce the heat soak and try to preserve the sensors and wires.

Note 7 - I will apologize to RB in advance - to me, the discs end up looking butt ugly. That's just my opinion. I cannot argue against their performance regardless of the appearance. At one point we cleared the cross drilled holes, but there was zero change in performance. I never had an "out-gassing" issue like I have experienced in a Camaro with stock CCMs. To me they felt every bit as good as PCCBs, but still different and maybe with a slightly lower friction level (more pedal effort)...stress maybe and also stress this is not a bad thing, just different. If anyone is on the fence about this system and asks me, I can recommend the RB CCM set-up. The parts supplied were very nicely made and finished, and fit straight out of the box with no modification. Our set-up was an odd one for sure, but Warren was very reactive and quick to respond. I can comfortably recommend without hesitation.




Rear



Rear - if you notice the rough pad edge, this was noticed very early and did not deteriorate with heat, time, or mileage. RB was aware and familiar and advised not to worry.



Front



Front

CobaltCr

[quote=DDonohue]Sorry for such a stupid long post. If you have insomnia, here is a cureÂ…/quote]

Thanks for a really nice write up of your experience.

Can you comment on whether you noticed if the pads restored the rotors?

Thanks

uscarrera

David great write up and really enjoyed the in car video of your run up the Pike. Enjoyed our talk at RR 5.
Thanks
Rich

Earlierapex

RB, this was exactly my previous question. This is a technical crowd. We aren't trying to be jerks, but we do expect claims to be backed by data, not theory.

The problem with theory (rather than data), is that you quickly end up multiplying assumptions by assumptions and reaching illogical conclusions. In this example, you've migrated your claim to imply that that your pads cause carbon rotors to operate at lower temps and extend life due to reduced heat-related oxidation due to more rapid heat dissipation due to the higher heat conductivity of the metallic pad layer on the rotor.

Ok, fine, but don't write a bunch of speculative theory as to why we should believe a wild story. Show us the average rotor temps with a controlled experiment with both types of pads on the same rotor.

RacingBrake

As a disclaimer this RB sintered pad effect was proven on GM CCM rotors only so far; ST rotors are being tested and we expect to have a result in about two weeks. But not on pccb yet, due to different generations we are not able to to confirm whether our sintered pad can produce the same repairing effect to pccb.

We all agree testing is believing so we are ready to modify our existing sintered pad shape (ZR1/Z28) for 991 GT3 calipers (but the wear sensor connections must be disabled due to OE calipers are closed top), you just simply swap OE pad with RB sintered, calipers and rotors can remain unchanged.

In case this test resulting some further disc damage (must verified by us prior) due to pad incompatibility, we will replace them with RB-ST rotors (you paid for the usage of the original pccb), and if they work just tell other here.

Those (presumably having issues with their pccb) who like to help the community can call (714-871-6392) or PM us.

RacingBrake

[QUOTE=CobaltCr;14335679]David's rotors were brand new with sintered so they are not relevant to your question of rotor restoration, but you still can clearly see those "transfer of layer" onto the rotor surface like below on a GT350.

Here is another vivid example on John's GT350 with RB CCM rotors and sintered (streetable vs. David's dedicated race compound) that he tracked on Mission Raceway (Canada) last Monday.




https://trackmustangsonline.com/thre...-2#post-182441

RacingBrake

Interim Report:

A pair of ST rotors from a GTR track customer that were severely oxidized and were considered as "discard" or "rebuilt" condition. We put them on to our shop car (2016 Mercedes CLS550) to test with sintered pads (trackabel street compound).

After these damaged ST rotors were installed, the car vibrated so violently (at any speed as the brake pedal was applied) that make it un-driveable, so next day the passenger side rotor was removed and replaced back to iron.

ST CCM-X rotor (Passenger side) removed after one day on sintered pad.



ST CCM-X rotor (Driver side) after 10 days of normal street driving with some occasional hard stops.



Detail view - A more continuous band of metallic finish can be seen.



Since ST discs are made from continuous fiber, the damage is in a "patch" pattern (than Brembo's chopped fiber which is more of a uniform and consistent manner), which makes the restoring process harder (larger spots to fill in) and longer in this restoration process which is somewhat expected.



We have also found that the wearing pattern of pad and rotor surface are in groovy pattern than Brembo's disc in a non groovy surface which coincides to how the respective carbon fibers are structured.

These pictures from the test can not represent what you will actually see with eyes unless taken by pro-photographer, however the effect of rotor surface restoration via the transfer of pad is evident and can definitely be felt by the driver, being the vibration amplitude is progressively getting diminished as the rotor surface looks better (more smooth shining area than spotty patches)

The long process and trouble involved perhaps not worth for a consumer than have it re-furbished, however the point of this test is to demonstrate the effect of a sintered pad can do to a CCM rotor that's severely damaged, better yet is to start the sintered pad in the beginning and avoid it, or mend the rotor with sintered pad before gets so bad.

RacingBrake

Passenger Side (Iron rotor)


Driver Side (ST CCM-X rotor)

RacingBrake

Stage of CCM rotor restoration process:
#1 Original set up (OE caliper, pad, and rotor)


#2 After switching to sintered pads (OE caliper)


#3 Replacing OE caliper to RB (sintered pad)


Two weeks ago Russ's Z28 brake system was sent back to us for check up and maintenance. We notice the front rotor was pitted and before asking Russ admitted he had to replace the front pad to OE/Brembo (for the last racing at North Cal), here are the pictures of his rear rotor. Basically the OE semi-metallic pads worn off all the metallic deposit on rotor surface and the rotor was back to the original condition (see pic# 1).




Rotor at this condition can chew up any pads MUCH faster than normal use, although the rotor thickness was checked and found to be almost no wear & within spec.

We advised him of no discs replacement is needed however he will consumer more pad wear during the pad breaking-in and layer transfer process.

Hope above self-explanatory facts can answer to your questions whether you shall use OE pads or alternative such as sintered pads exclusively developed for CCM rotors.

RacingBrake

We offered two compounds:

XC-40 trackable street (or streetable track) Can go between street and track w/o having to switch the pad like semi-metallic.
XC-41 Dedicated track/competition racing - Not suitable for street driving.

Since these pads are made with high and consistent COF (0.6-0.65) so we recommend only for CCM rotors which are very hard and do not get soft like iron. Although they also perform extremely well on iron rotor (tested on Momentary Racing's Viper Race car & Focus RS) but will be at the cost of rotor wear, even on RB rotors that are known to be the most durable in the industry at 200-240 Brinell hardness because iron rotor gets soft at elevated temperature.

RacingBrake

You bet.

Not only the coefficient of friction (COF) is higher (0.6 - 0.65) than conventional semi-metallic pad (0.5), but its COF is FAR more consistent (stable brake torque) during the entire operating temperature cycle.

Why this is possible?

Because RacingBrake sintered pad is made of 100% metallic powder and formed under extreme high temperature and pressure, unlike semi-metallic which the friction compounds are held together by resin that tends to get soft, or melt under elevated braking temperature, that's when the pad lose its COF and quicken the wear.

RacingBrake

Long term review on CCM/sintered pad combo by a GT-350 track driver:
https://trackmustangsonline.com/thre...-2#post-202847

It's half way through the 2018 track season and I've put three more track days on my CCB's.

My opinion of them hasn't changed. I love these things. They are the best brakes I've ever driven with, and I've had AP Racing, Brembo Racing, Stoptech and a variety of OEM setups.

For track work, the "streetable" sintered pads are perfect. Super consistent delivering massive stopping power, excellent modulation and consistent brake feel from cold to hot. As for wear, after six track days, the total pad thickness (two pads pressed face to face) has gone from 34.0 mm to 33.0 mm. That's consistent with last year's level of wear. One thing to note - these pads can be noisy. When they're hot they're quiet, but cold, they make a soft whirring sound and the occasional squeal. I've found that a few minutes with a file to chamfer the edges of the friction material seems to reduce the squealing to a level that I can live with.

There is a new addition to the setup for this year - I picked up a set of Racing Brake rear rotors. They maintain the hand brake function (unlike virtually every other aftermarket rear rotor for the GT350) and they are a direct fit into the existing setup. They're 380x28, which is 2mm thicker than OEM, but the OEM calipers take new pads with no problem. I'm running mine with Pagid RSL29's and the brake balance with the front is excellent. They're directional rotors with large vanes so they cool really well. You lose a couple of pounds of weight, but it's not a major reduction - it's all about shedding heat for these things.

Through our long term track test and feedback we can conclude that when a proper pad (especially for track application) is installed, CCM rotors can last 3/4/5.. times longer, more cost effective than conventional iron set up in additional to the less down time, consistent brake torque delivery with no fade, no crack, confidence inspiring and worry free braking performance that some serious track racers are looking for.

Perimeter

Is there any benefit to using the XC-40 sintered pads on OEM PCCB rotors for street use?