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      06-15-2015, 07:54 AM   #67
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Quote:
Originally Posted by CanAutM3 View Post
I would just like to precise that adhesive friction is not exclusive to the CCB. My understanding is that every pad has a different proportion of abrasive and adhesive friction. Where more street-able pads have a stronger abrasive bias and more track oriented pads have a greater adhesive bias. That is why track pads need a proper bedding to operate correctly. A thin layer of pad material is necessary on the disc for the adhesive friction to take effect.

Even the stock pads for the irons have some adhesive friction built in. However, since the pads are not intended for track use, when they see sustained high temperatures, they transfer too much material on the rotors smudging them with uneven pad material which results in brake shudder.
Absolutely. Typical brakes for decades function with both adhesive forces (material interactions/interatomic forces) and abrasive friction forces (stress interactions/abrasion). Hence in the end you end up with adhesive wear particles and abrasive wear particles.

Edit: Tribology is a crazy-wild subject, especially when you look at stuff like lubricant separated surfaces (i.e. rod bearings), but I have very limited experience with the subject in the realm of brakes. Perhaps what is predominantly different is: the ratio of adhesion to abrasive wear versus operating load/temperture range? Meaning that at very high brake pad to rotor interface temperatures, perhaps the carbon rotor solution is operating much more in the realm of adhesive forces than the iron setup? Interesting subject...perhaps one to throw on the stack to study.
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      06-15-2015, 08:25 PM   #68
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Have been following all the ccb threads with much curiosity. Would be curious to see how a set of backing plates and cooling ducts to the brakes would help with overall wear. And curious what the general consensus is, I'd be keeping my car for 5 years, maybe longer. Would you still do ccb? Would likely consider using iron rotors for track duty, which would be 1-2 events a year. But I drive hard and fast, to me, anyone who says you can use oem pads at the track and be fine are automatically discredited for not driving fast enough. Seems the ccb pads are indeed capable of this but definitely not the iron brake setup.
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      06-15-2015, 09:35 PM   #69
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Quote:
Originally Posted by Zoli007 View Post
Have been following all the ccb threads with much curiosity. Would be curious to see how a set of backing plates and cooling ducts to the brakes would help with overall wear. And curious what the general consensus is, I'd be keeping my car for 5 years, maybe longer. Would you still do ccb? Would likely consider using iron rotors for track duty, which would be 1-2 events a year. But I drive hard and fast, to me, anyone who says you can use oem pads at the track and be fine are automatically discredited for not driving fast enough. Seems the ccb pads are indeed capable of this but definitely not the iron brake setup.
I have read your post five times and I just can't figure what you are trying to say .
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      06-15-2015, 10:34 PM   #70
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Yeah I was rambling.... was waiting at the airport for a while and didnt really pay attention to what I wrote...

In regards to cooling, a lot has been talked about regarding the temperature of the rotors and pads and how the hotter they get, the more they tend to wear (the pads that is) Would be curious to see how properly directed brake cooling ducts would help with keeping temps in check. Would it prolong pad life a bit while keeping the brake feel and stopping power the same.

Then, on a completely different subject, would the group chose to option the CCB's on a car they would expect to keep for 5-7 years?

Hopefully makes more sense. Maybe this is why I mostly read and lurk heh.
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      06-20-2015, 05:48 AM   #71
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Hi guys, first post, and very happy to be part of this community.
So, yesterday I went out for the first track day with my M4 with CCB.
I was in Imola.
Car was great, but I found the feeling with the pedal getting worst after a few hard break.
The pedal got very long, and not very consistent
Maybe change the brake oil and brake line?

thanks
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      06-20-2015, 07:34 AM   #72
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Quote:
Originally Posted by Teo28 View Post
Hi guys, first post, and very happy to be part of this community.
So, yesterday I went out for the first track day with my M4 with CCB.
I was in Imola.
Car was great, but I found the feeling with the pedal getting worst after a few hard break.
The pedal got very long, and not very consistent
Maybe change the brake oil and brake line?

thanks
Must be pretty cool to drive at Imola

With the hotter operating temperatures of the CCB, using a better fluid than the OE one is probably more needed with the CCB. Before changing the brake lines, I would just swap the fluid for Castrol SRF and see what gives.
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      06-20-2015, 11:26 AM   #73
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Yes very cool, quite technical, but a lot of fun.
I think I'll do that, and change the oil first.
Here some pics of the front disk. You can see that some holes close down... Maybe some material from the pads
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      06-20-2015, 11:45 AM   #74
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Quite strange the back disk don't have a smooth surface
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      06-20-2015, 11:50 AM   #75
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Here you can see it better
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      06-21-2015, 07:44 AM   #76
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Quote:
Originally Posted by Teo28 View Post
Here you can see it better
Are those grooves in the disc or simply pad deposit?

Tough to tell from the pictures.
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      06-21-2015, 08:30 AM   #77
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Quote:
Originally Posted by CanAutM3 View Post
Are those grooves in the disc or simply pad deposit?

Tough to tell from the pictures.
Looks like pad deposits to me but I agree it's hard to tell. My rotors look like this when I have the Carbotechs on too.
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      06-21-2015, 05:19 PM   #78
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I think is pad deposit, both disks look the same
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      06-21-2015, 06:12 PM   #79
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Quote:
Originally Posted by Teo28 View Post
I think is pad deposit, both disks look the same
If that's the case, then all is good IMO
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      06-22-2015, 03:04 AM   #80
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Yep, all good! I guess the only problem with CCB so far is the brake fluid
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      06-22-2015, 10:19 AM   #81
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Quote:
Originally Posted by Zoli007 View Post
In regards to cooling, a lot has been talked about regarding the temperature of the rotors and pads and how the hotter they get, the more they tend to wear (the pads that is) Would be curious to see how properly directed brake cooling ducts would help with keeping temps in check. Would it prolong pad life a bit while keeping the brake feel and stopping power the same.
Cooling is a good insurance I think; however, at this stage it is important to keep everything stock for me to observe the results, and of course, not to give the chance to the dealer for any sort of objections.

At the same time, directing cooling is not going to be easy for this car due to how the under-belly is designed and the darn dust shields around the rotors.
Quote:
Originally Posted by Teo28 View Post
Here you can see it better
Those are streaks of pads deposits, not grooves. Interestingly I don't have those on my discs. I just came back from a track weekend, had few runs and not many, but as soon as I change my wheels, I will double checks and post latest photos.

Thank you very much for providing your feedback, very helpful.
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      08-11-2015, 01:28 AM   #82
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FTS Thanks again for the update. Just wondering what are your current thoughts on the CCBs given the amount of track and street miles that you have put on so far. Where you able to to measure the weight of the rotors? How about the wear on the OEM pads at the moment? Any thoughts on replacing the OEM pads with something like RSC1 (http://www.kempower-motorsport.com/i...oduct_id=30311), which seems to be pretty well received by the Porsche guys.

I would assume the rotors used on the M4 are the same construction as the Gen 3 PCCB on the newer Porsches, given that they are all manufactured by Brembo. It seems like the Gen 3 rotors are much more durable than the previous generations CCBs, but it is still a little early to give the verdict on these.

Not sure if you have seen this thread on RL, but there are some interesting information on it that you and rest of the guys who are considering CCB on this car might find it helpful: http://rennlist.com/forums/991-gt3/8...ck-thread.html
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      08-14-2015, 07:42 PM   #83
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Quote:
Originally Posted by Cloud9blue View Post
FTS Thanks again for the update. Just wondering what are your current thoughts on the CCBs given the amount of track and street miles that you have put on so far. Where you able to to measure the weight of the rotors? How about the wear on the OEM pads at the moment? Any thoughts on replacing the OEM pads with something like RSC1 (http://www.kempower-motorsport.com/i...oduct_id=30311), which seems to be pretty well received by the Porsche guys.

I would assume the rotors used on the M4 are the same construction as the Gen 3 PCCB on the newer Porsches, given that they are all manufactured by Brembo. It seems like the Gen 3 rotors are much more durable than the previous generations CCBs, but it is still a little early to give the verdict on these.

Not sure if you have seen this thread on RL, but there are some interesting information on it that you and rest of the guys who are considering CCB on this car might find it helpful: http://rennlist.com/forums/991-gt3/8...ck-thread.html
Sorry for my late reply. The rotors are still going on very strong, no sign of overuse or abuse. I haven't weigh them yet as there hasn't been a need due to still fully visible wear indicators on the outside of the rotors.

I have been in touch with Pagid on the RSC pads, which I will use as soon as they come out, but I haven't received a notification that the front pads being released yet. I am almost done with the second set of stock pads, they don't last long especially in 100 degF ambient temps.

The M CCB rotors seem to be exactly the same as PCCB v3 ones, the main difference is that PCCBs, now, are 14 mm larger in diameter. And since both the 911 and Caymans are significantly lighter than our cars, they are going to last longer, maybe even 40-50% longer.

The best way I can summarize my experience is that if I were buying car again today, I'd order MCCBs without thinking. But I also have the backup plan for iron rotor replacements unless rotors prices come down significantly.
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      09-01-2015, 08:24 PM   #84
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Quote:
Originally Posted by FTS View Post

I have been in touch with Pagid on the RSC pads, which I will use as soon as they come out, but I haven't received a notification that the front pads being released yet. I am almost done with the second set of stock pads, they don't last long especially in 100 degF ambient temps.
Thanks for your CCBs on track feedback.

The Pagid RSC pads for the F8x front CCB calipers are the same as the M5 w/CCB (calipers are the same except color, even the piston sizes). I would guess that they just found that out and applied the same P/N to the F8x.

A couple of questions for you, please...

- Edit: got the rear pad Detail Reference from Pagid. Thanks...

- can you measure the distance from the rotor surface to the hat top whenever you have a chance, please?


I am trying to find out if the front F10 M5 steel rotors (400x36) with a 28mm hat can be used with the CCB front calipers without changing the caliper OEM bracket. Front pads then can be M5 steel rotor front pads; the rear pad for steel rotors will depend on that Detail Reference # above.

Last edited by Technic; 09-02-2015 at 05:07 PM..
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      09-05-2015, 09:11 PM   #85
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Quote:
Originally Posted by FTS View Post
...

(1) the pads oxidize with heat and be consumed

...

I change these pads before reaching 50% wear, because I am told by Pagid and others that as the pad thickness decreases and consequently their heat sink capacity, I would be exchanging the wear with rotor oxidation. It is important to keep the rotors below oxidation temps, 1150 Fdeg in the case of MCCBs. Thus far I have been able to do that.

...
In reading this there are a few points that spring to mind:

I don't believe the pads are of the same construction as the discs and that it is only the discs which are subject to oxidising wear.

The 50% wear limit is not due to heat sink capacity but for reduced thermal insulation leading to more heat being transferred into the callipers and thus the brake fluid.

The temperature indicating paint is showing the temperature at the periphery of the disc, about as far from the heat generation area of the disc and in the area of most cooling air flow. I would expect the braking surface to be subject to a significantly higher temperature.
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      09-14-2015, 04:04 PM   #86
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Quote:
Originally Posted by Technic View Post
A couple of questions for you, please...

I am trying to find out if the front F10 M5 steel rotors (400x36) with a 28mm hat can be used with the CCB front calipers without changing the caliper OEM bracket. Front pads then can be M5 steel rotor front pads; the rear pad for steel rotors will depend on that Detail Reference # above.
To my best knowledge and per dealer, the M5 rotors+hats will fit directly. I haven't had the need to test that, so I am going by their word so far.

It will be couple of months before I need to change my wheels for track, at that point I'll try to measure. It maybe difficult to measure because the dust shields curve forward towards the rotors, leaving no room to properly measure such distance, but I'll try.
Quote:
Originally Posted by crashtestdummy81 View Post
In reading this there are a few points that spring to mind:

I don't believe the pads are of the same construction as the discs and that it is only the discs which are subject to oxidising wear.
Essentially correct, I used the same term to describe the wear, but technically you are right of course.

Quote:
Originally Posted by crashtestdummy81 View Post
The 50% wear limit is not due to heat sink capacity but for reduced thermal insulation leading to more heat being transferred into the callipers and thus the brake fluid.
Yes that is correct, no other reason otherwise.

Quote:
Originally Posted by crashtestdummy81 View Post
The temperature indicating paint is showing the temperature at the periphery of the disc, about as far from the heat generation area of the disc and in the area of most cooling air flow. I would expect the braking surface to be subject to a significantly higher temperature.
This is essentially correct as well; however, the 'surface' area is not subject to oxidation (the ceramic coating), hence not critical to measure IMHO. Additionally, all tests show that the thermal conductivity of the inner material to be very high resulting in very rapid heat transfer across the whole inner material area significantly improving thermal equivalency. Consequently, heat measured at the periphery is quite valid in measuring total heat generated.
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      09-14-2015, 08:55 PM   #87
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Thanks...

Quote:
Originally Posted by FTS View Post
To my best knowledge and per dealer, the M5 rotors+hats will fit directly. I haven't had the need to test that, so I am going by their word so far.

It will be couple of months before I need to change my wheels for track, at that point I'll try to measure. It maybe difficult to measure because the dust shields curve forward towards the rotors, leaving no room to properly measure such distance, but I'll try.
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      10-14-2015, 10:18 PM   #88
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Saw this on the Rennlist PCCB thread

I'm no expert but this looks more like deterioration from something other than usage, is this how CCB rotors usually look when worn?


http://rennlist.com/forums/991-gt3-a...thread-12.html

The poster says

"...Have 30 k miles on car 25+ track days, i have no clue to how many track miles?

Took Euro Delivery 6/5/14 model is a 2014 TTS, withTubi Race Exhaust, GIAC Stage2+, H&R lower springs, Champion IC, and a few more things.
Yes, i am driving the **** out of it!..."
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