Carbon Brakes - walk away or worth it?

[iandc]

Adam B said:

please god

That was before the very last last post!!

[ChrisW.]

I never raced with ceramics. We are talking about a road car ... and for track days.

PCCB are absolutely phenomenal.

It's expensive swopping pads at 50% all-round, but they are phenomenal.

If I do destroy the PCCB's I will not replace them with anything other than affordable alternatives to fit the PCCB calipers, but after Spa and Zandvoort a couple of weeks ago I'm told the discs are in great condition.

As a new option or as a secondhand must-have option, for me they are a no-brainer. But i would get a good inspection if secondhand

I'm at Donnington on Thursday if anybody want a passenger ride in the racing Cayman ...

[Neverbeen-too-fast]

Hi Guys,

I am 43 from Cologne Germany and new to this board. For weeks now my search for information on the CCB is giving me a headache and this thread here is by far the best I have found on the net. And it is the reason why I did read more on PH and it is the reason why I did register here. You folks are "different" than the majority of people posting in other car nuts forums.

Having ordered an M6 convertible CP last week I am still not sure wether to go with ceramik or steel.
I admit that 8000 bucks for the front or even more in total when worn out are serious money for me and would be happy to avoid that for as long as possible.

Living between cologne and the national park of northern Eiffel (mountains) I do about a daily 70miles on flat and winding b roads "without police control"(!)
So going very very fast on these roads is everyday business. Despite that the Serpentines of the Eiffel and the Nürburgring are only a 30/60 minute drive away.

I have a Question, which I am absolutely unable to obtain an answer on - so you guys are my last hope ,-)


I understand that the wear of ceramics does (almost) not come from the friction between the rotor and the pad (as they work without abrasive friction) but from the oxidation. Some here say they start oxidising at 750 degrees - I have also read about 600 degrees.

And I have read about people talking about having to replace the rotors after 2 Trackdays / 10 days / 20 days... 1000km / 2000km of track...

so... all this is very vague - does anybody know many hours the rotors can take of oxidation before worn out?
Does oxidation occur faster at 1000 degrees than an 750? (which I assume)

If I assume that the Nürburgring NOS will be the only track I will visit from time to time - does anyone know how hot brakes become here?
I heard the NOS ist not very bad for brakes?

Are there aftermarket systems which can tell me the rotor temp while driving?

I know the M6 convertible is not a GT3 ... so lets not talk about the sense of it - but I LOVE high tech stuff like CCBs..

I apreceate your comments
regards
ralph

by the way - my actual car is an M4 Convertible.

Edited by Neverbeen-too-fast on Monday 10th July 13:56

Edited by Neverbeen-too-fast on Monday 10th July 13:57

[Slippydiff]

Neverbeen-too-fast said:

Hi Guys,

I am 43 from Cologne Germany and new to this board. For weeks now my search for information on the CCB is giving me a headache and this thread here is by far the best I have found on the net. And it is the reason why I did read more on PH and it is the reason why I did register here. You folks are "different" than the majority of people posting in other car nuts forums.

Having ordered an M6 convertible CP last week I am still not sure wether to go with ceramik or steel.
I admit that 8000 bucks for the front or even more in total when worn out are serious money for me and would be happy to avoid that for as long as possible.

Living between cologne and the national park of northern Eiffel (mountains) I do about a daily 70miles on flat and winding b roads "without police control"(!)
So going very very fast on these roads is everyday business. Despite that the Serpentines of the Eiffel and the Nürburgring are only a 30/60 minute drive away.

I have a Question, which I am absolutely unable to obtain an answer on - so you guys are my last hope ,-)


I understand that the wear of ceramics does (almost) not come from the friction between the rotor and the pad (as they work without abrasive friction) but from the oxidation. Some here say they start oxidising at 750 degrees - I have also read about 600 degrees.

And I have read about people talking about having to replace the rotors after 2 Trackdays / 10 days / 20 days... 1000km / 2000km of track...

so... all this is very vague - does anybody know many hours the rotors can take of oxidation before worn out?
Does oxidation occur faster at 1000 degrees than an 750? (which I assume)

If I assume that the Nürburgring NOS will be the only track I will visit from time to time - does anyone know how hot brakes become here?
I heard the NOS ist not very bad for brakes?

Are there aftermarket systems which can tell me the rotor temp while driving?

I know the M6 convertible is not a GT3 ... so lets not talk about the sense of it - but I LOVE high tech stuff like CCBs..

I apreceate your comments
regards
ralph

by the way - my actual car is an M4 Convertible.

I guess it depends on how serious you are about monitoring the disc temperatures

I've seen these mounted on development Jaguar F types with ceramic brakes :

http://www.thermosensedirect.com/acatalog/brake_te...

I wouldn't have thought it would be difficult to rig them up with a 4 channel digital readout :

http://www.thermosensedirect.com/acatalog/temperat...

It's heavy car, though the discs are a decent size and should be able to deal with the heat management required.

Disc wear occurs both through oxidisation and mechanical abrasion, the higher the temps, the higher the oxidisation (the oxidised surface wears quicker as a result)

[Dr S]

The main issue with ceramics is not the temperature whilst doing actual track work (else they'd be useless) but appropriate cool down thereafter. On shorter circuits like the N GP track you should count for a whole lap. When doing tourist laps on Nordschleife you probably want to take out pace after Pflanzgarten 2 when exiting on Döttinger Höhe, i.e. you want to avoid full-on breaking already into Schwalbenschwanz

[Neverbeen-too-fast]

1 question -
2 answers -

and I am completely in love with this forum!

That is what I call informative, competent and helpful!

Thanks a lot.

It brings me much nearer to "my" ceramics.



"The main issue with ceramics is not the temperature whilst doing actual track work (else they'd be useless) ..."

I have the imagination that the CCB can bear - say 2h - of moren than 600 degrees - and every hard cornering with a peak temp over 600 will substract a few seconds from that 2hours.
Of course - if you heat the breaks to 800 degrees and park the car and it takes 30 min to cool below 600 - that would be "waste of time".

Edited by Neverbeen-too-fast on Monday 10th July 16:25

[ORD]

Hard track work in an M6 Convertible? It would be cheaper and more fun to buy a much lighter and faster car for track days, surely?

[Neverbeen-too-fast]

yes! - I guess it would.

But I am not sure If I like tracking more intensely for a longer time... and I dont want to pay 16000 euros for CCB while finding out.

In a perfekt world I would track the M6 with lower than 600 degrees brake temps for a while... get the track virus (or not) and decide for an addition track car.
with no (serious) additional cost to the m6.

[ORD]

Good stuff

[Porsche911R]

Dr S said:

The main issue with ceramics is not the temperature whilst doing actual track work (else they'd be useless) but appropriate cool down thereafter. On shorter circuits like the N GP track you should count for a whole lap. When doing tourist laps on Nordschleife you probably want to take out pace after Pflanzgarten 2 when exiting on Döttinger Höhe, i.e. you want to avoid full-on breaking already into Schwalbenschwanz

I have seen 991RS and 991 Turbo S with smoking pads, if you don't cool the disc , the pads fall apart they heat soak into the fluid boiling that.

that's why I think PCCB are a bit daft for any track work, as you are limited on pad. and have to change them 50% worn to try and manage heat and heat transfer.

Not only that red flags are very common as track days grow, so no chance to cool brakes. last one I went on there were 7 red flags !

[Slippydiff]

Dr S said:

The main issue with ceramics is not the temperature whilst doing actual track work (else they'd be useless) but appropriate cool down thereafter.

So by your reckoning you could stick the ceramic discs on a brake dyno, replicate 150mph to 0 stops one after the other for 6 months solidly, and as long as you allow them to cool down for half an hour before switching pulling the plug on the dyno, there'd be no discernible wear to them ? Riiight.

[Neverbeen-too-fast]

Hmmmm....

Very good point. Noone ever thought of this.... or wrote it down...

I actually do not Think I will attend so many track days.

I could go to the NOS almost every workday I like With not much trafic before noon.

Anyway...

I just dont like the idea of beeing surprised by wear and cost.
If there are ways to controle it....
I am fine

[Neverbeen-too-fast]

No.... you could do the dino thing that way aß long aß Temp stays below 600 all the Time.


Sorry for my typing....

German mobile...

Edited by Neverbeen-too-fast on Monday 10th July 18:11

[Slippydiff]

Neverbeen-too-fast said:

No.... you could do the dino thing that way aß long aß Temp stays below 600 all the Time.


Sorry for my typing....

German mobile...

I've seen roadgoing use only 996 and 997 GT3's fitted with PCCB's, both had large mileages on them, both had worn but serviceable discs (because the brake pad abrades the face of the rotor) elevated temperatures just expedites the process.

The original PCCB's fitted to the 996 GT2 were said to last 120K miles, most lasted no more than handful of trackdays because they overheated and de-laminated due to poor heat management. Those failures had nothing to do with not doing a couple of cooling down laps after they'd been overheated.

The discs on your M4 will be waaaaay larger and thus will be better able to manage the heat build up ie they'll shed the heat quicker and their increased mass will allow them to function without overheating (in theory) but if you were to compare a car's discs after 50k miles that's driven solely on the road (albeit quickly), compared with a car's discs who've done 50k miles on the road AND track (such as yours) I guarantee your discs will be be more worn than those on the road use only car.

[Neverbeen-too-fast]

I know early Porsche rotors had issues ...

BMW Claims Cars Life durability With road only Use.
BMW claims also 300.000km for their engines...


If that would be Reduced to 150.000 With leasure Tracking i would be happy.

I had a 535d With Steel that needed replacement After only 200.000km.

.... I do not break that often ...

[Neverbeen-too-fast]

I have also found the formula to calculate the rise in Break Temp given the rotors mass.. the Cars mass... und the difference in Speed.

Starting at 40 degrees Celsius the m6 Never reaches 600 c ...

Not even 150 mph to zero.

BUT i have no data in how this builds up ob track

[Dr S]

Slippydiff said:

Dr S said:

The main issue with ceramics is not the temperature whilst doing actual track work (else they'd be useless) but appropriate cool down thereafter.

So by your reckoning you could stick the ceramic discs on a brake dyno, replicate 150mph to 0 stops one after the other for 6 months solidly, and as long as you allow them to cool down for half an hour before switching pulling the plug on the dyno, there'd be no discernible wear to them ? Riiight.

What real world scenario of track driving to you intend to replicate with your exercise?

[Kawasicki]

mrdemon said:

you cannot lock up a wheel at 120mph, brakes are not that powerfull to do that.

Pistonheads is funny sometimes

[MDL111]

Neverbeen-too-fast said:

Hmmmm....

Very good point. Noone ever thought of this.... or wrote it down...

I actually do not Think I will attend so many track days.

I could go to the NOS almost every workday I like With not much trafic before noon.

Anyway...

I just dont like the idea of beeing surprised by wear and cost.
If there are ways to controle it....
I am fine

My FF has ceramics (similar weight to the M6 I'd imagine) and I drive in Germany, mostly Autobahn with some mountain roads mixed in in the Alps though and not particularly aggressive driving style so plenty of cooling down time/not too much hard braking. So far the car has done about 38k km (I did c 27k of those) and I have only had to change rear brake pads. I think they probably last (famous last words....) if you don't do track days.

[Slippydiff]

Dr S said:

What real world scenario of track driving to you intend to replicate with your exercise?

Anyone know where the "Whoosh parrot" emoticon is to be found ?

Which parallel universe do you live in when you think that two cooling down laps will stop PCCB discs from wearing out prematurely ?
I'd guess the same one that says don't put the handbrake on a 996/997 GT3 when you park up in the paddock after session on track .....