Brakes

[h_bakken]

Feel free to redirect

Got my first track day coming up in 6 weeks, very excited, just ordered helmet gloves and shoes, Quick Jack.

Anyhoo-

My cars CCB have never seen track or hard use as far as I can tell. Muffler is not discolored, disc wear indicators pristine.

I'm going to not worry about the CCB brakes for now. I won't be pushing things as a complete novice. I will have both an AM and PM session with instructor.

So if I decide to replace brakes and wheels if I get the track bug, what are people running or recommending for brakes?

[Gomeler]

Less expensive option is the M2C rotor + a track-oriented pad for the CCB/M2C caliper. Requires a 19" up front, so I guess run something like 19x10/18x11? Can't comment on that.

Buy once, cry once. AP9668/AP9449 + track-oriented pad(Carbotech XP12/Hawk DTC-70 have worked well for me. Think people also like the PFC-08?). That enables the use of 18" wheels, I highly recommend 18x11 square via Apex EC-7 wheels. Been fantastic for tire wear with the ability to rotate corners.

[h_bakken]

Originally Posted by Gomeler

Less expensive option is the M2C rotor + a track-oriented pad for the CCB/M2C caliper. Requires a 19" up front, so I guess run something like 19x10/18x11? Can't comment on that.

Buy once, cry once. AP9668/AP9449 + track-oriented pad(Carbotech XP12/Hawk DTC-70 have worked well for me. Think people also like the PFC-08?). That enables the use of 18" wheels, I highly recommend 18x11 square via Apex EC-7 wheels. Been fantastic for tire wear with the ability to rotate corners.

Appreciate this.

Had been looking at Apex/AP.

Also appreciate your track notes on the other threads

[786]

Do you guys think it’s worth it to switch to M2C rotors/pads for a street car? My disc wear indicators look brand new and some people tell me to switch and save the CCBs while others say they’ll last forever on a street car so don’t mess with them.

[h_bakken]

Originally Posted by 786

Do you guys think it's worth it to switch to M2C rotors/pads for a street car? My disc wear indicators look brand new and some people tell me to switch and save the CCBs while others say they'll last forever on a street car so don't mess with them.

If you're not going to the track then I would definitely leave the brakes alone forever.

I did a lot of reading about carbon ceramic brakes because I was in the market for multiple cars many of which had factory option CCB. It was quite a revelation to see that Porsche techs Admitted to the press a couple years back that iron rotors are recommended over CCB for track cars.

To cut to the chase, CCB are lighter and reduce rotating inertia as well as unsprung mass, all good characteristics. They're just very expensive to replace and are susceptible to the severe heat cycles which occur on track but do not occur on the street.

They actually lose mass due too complex chemistry between The carbon and other components of the rotor and the oxygen in the air. I don't quite understand all that but...

For a street car it is not an issue, the carbons should outlast iron rotors by a good margin. Added benefit that they generate very little brake dust as opposed to standard iron rotors and pads.

I understand that there are different types of carbon ceramic discs and some of them are more suitable for track use but overall I think you will see very few track cars running carbon unless of course the owner has so much money they don't care about a $10-$15,000 replacement.

Porsche has a relatively new surface coated brake which apparently has a coating of diamond on top of iron which are sort of a midway thing between carbon and iron rotors, about halfway between in expense. I saw these on "engineering explained" but can't remember a whole lot about them.

One thing I have read is when the BMW carbons are wet and cold they can have very little braking power until you heat them up and evaporate the water. Has given some people quite a fright.

[White340]

If you wear out the rotors you can eventually replace them with steel rotors. Replacing them early to avoid wear seems like a waste. How many people really keep this car forever and when would you use them if you swapped to steel before they wore down.

[the_scotsman]

Originally Posted by White340

If you wear out the rotors you can eventually replace them with steel rotors. Replacing them early to avoid wear seems like a waste. How many people really keep this car forever and when would you use them if you swapped to steel before they wore down.

Actually this makes sense, Keep workable carbon rotors for when you sell the car.

[786]

Thanks for the insight and viewpoints. I think I’ll stick with the stock CCB for now. They look brand new and stop very well, I’m probably overthinking things as usual. If I switch to iron rotors and put the CCBs on a shelf to save for the next owner I’ll diminish the experience for myself and I may not sell the car anyway.

[4play]

A lot of the panic around track day usage and wear is overhyped.

There are of course examples of people taking their brand new GT3 or 458 Speciale to the track and destroying the rotors in a single weekend, but there isn't that much oxidative wear unless you are on a low speed track with minimal cooling and just absolutely hammering (overusing) the brakes.

If you are doing a lot of track work, I would try some improved ducting and track CCB pads (Pagid RSC-1) before going to more extreme options. At the very worst, you burn up a set of CCB rotors and then can either opt for the M2C iron rotors or a full on AP setup.

Replacement rotors aren't as expensive as people make them out to be. I have a set of brand new CCB rotors and pads that I am selling and it was not a 5 figure amount to acquire them (nor am I asking a 5 figure amount). The extended service life in normal or aggressive street use mostly offset the higher cost of entry.

If you're tracking every weekend or something, maybe CCB is not the best, but otherwise just run them and don't worry.

[786]

Thanks, will do. Just curious what a new set of CCB rotors and pads costs these days?

[Gomeler]

^ is a very good point. Spec a solution for your intended use. I comment with the expectation that everyone is going to the track every 3 weeks, so an AP setup makes sense

[4play]

Originally Posted by 786

Thanks, will do. Just curious what a new set of CCB rotors and pads costs these days?

I have mine for sale for $6k including shipping. They aren't too unreasonable, considering the M2 Comp conversion parts are $2-3k.

[Lienrocs]

AP with some good fluid. Hands down. I run the 9668/9449 set up and it's fantastic. Tons of pad options and when/if you sell the car you can put the stock set up back on and have as new brakes on the car and get a good chunk of change back selling the AP set up.

[SYT_Shadow]

If you're a newbie then track it with CCBs, however, I suggest that if you like it and start going more then please move to a BBK so you don't ruin your CCBs. They will be needed for resale eventually

The AP RadiCals are overrated. They are off my car and the rears are for sale if someone wants them.
Alcon's new kit is significantly improved vs the RadiCals but this is not a very difficult achievement.

So far I've had all three on my car and:
PFC ~= Alcon
PFC > AP RadiCal
Alcon > AP Radical

[786]

I had Alcons on a previous car and they were faultless fyi.

[FormulaMMM]

Stock ccb will be fine for a novice. In fact, the only BMW system to date that you can run in completely stock form and achieve strong, consistent performance. So, I'd recommend you give them a try.

The problem comes with increased pace. And it's my perception that much like the star spec Cup 2, BMW spec'd a "lite," street-oriented ccb system. Not intended for long-term track durability.

I had better luck with the GM ccb (pads & discs are in better shape after more sessions same track), Porsche GT guys often swap, but many experienced drivers run the stock system and get multiple seasons. Perhaps because these systems were engineered with track use in mind, and other than the rear pad, the GTS ccb system is the same as the standard M3/M4 street system.

Also think the extremely tight packaging and lack of cooling on the GTS fronts is a problem. Hottest wheels post-session that I've ever experienced.

I switched out for the same AP Racing system (+ Ferodo DS3.12 pads) as Lienrocs and Gomeler, and some others on the forum.

Have only heard good things about Alcon as well.

[SYT_Shadow]

The Alcon kit I'm referencing is brand new, 25mm front pad, 20mm rear pad, 380mm front rotor with 36mm thickness.

[Gomeler]

You've mentioned an Alcon kit for a while now, where would someone get it if they were interested?

[SYT_Shadow]

Originally Posted by Gomeler

You've mentioned an Alcon kit for a while now, where would someone get it if they were interested?

I believe Bimmerworld is the only reseller for this specific Alcon kit. Very nice stuff.

[h_bakken]

Originally Posted by FormulaMMM

Stock ccb will be fine for a novice. In fact, the only BMW system to date that you can run in completely stock form and achieve strong, consistent performance. So, I'd recommend you give them a try.

The problem comes with increased pace. And it's my perception that much like the star spec Cup 2, BMW spec'd a "lite," street-oriented ccb system. Not intended for long-term track durability.

I had better luck with the GM ccb (pads & discs are in better shape after more sessions same track), Porsche GT guys often swap, but many experienced drivers run the stock system and get multiple seasons. Perhaps because these systems were engineered with track use in mind, and other than the rear pad, the GTS ccb system is the same as the standard M3/M4 street system.

Also think the extremely tight packaging and lack of cooling on the GTS fronts is a problem. Hottest wheels post-session that I've ever experienced.

I switched out for the same AP Racing system (+ Ferodo DS3.12 pads) as Lienrocs and Gomeler, and some others on the forum.

Have only heard good things about Alcon as well.

What is GM CCB

[4play]

Originally Posted by h_bakken

What is GM CCB

General Motors - It's the Brembo CCM brakes, as found on Ferrari/Alfa/Maserati, Chevy, and other vehicles. Our brakes are Brembo CCB, as are AMG/Porsche/VAG.

Both have discs made of silicon carbide with carbon fiber reinforcement, just 2 different construction methods. CCB is a ceramic disc with a wear layer on the top (a little over 200g worth on our CCB front discs), while CCM is a slightly different type of ceramic material with no wear layer.

I suspect the OEM BMW CCB would perform much better on track if they had adequate cooling. If you could keep the disc surface just a bit cooler, there would be hardly any oxidization and the brake discs would last a really, really long time. Of course, the flip side is that the brakes would be quite cool by the end of long straights / sections not requiring brakes, and might not perform as well during initial brake application.

[FormulaMMM]

Originally Posted by 4play

I suspect the OEM BMW CCB would perform much better on track if they had adequate cooling. If you could keep the disc surface just a bit cooler, there would be hardly any oxidization and the brake discs would last a really, really long time. Of course, the flip side is that the brakes would be quite cool by the end of long straights / sections not requiring brakes, and might not perform as well during initial brake application.

I think that's true, especially up front. and given how hot they run too much cooling is pretty unlikely.

Worth keeping in mind the Porsche is on their 4th gen PCCB development (20 years). I don't know where M's F8x CCB system would plug in on the developmental spectrum, but probably safe to assume from performance & durability standpoints they're not equal. Just as not all iron rotors are equal in quality or longevity.

Z/28 system was designed from the outset for track use. Discs aside, a comparison in pad wear rate between that system and M's indicates differing design/purpose. I'd estimate at least 2x faster pad wear rate for the M system. GTS is faster, but it ain't heavier or harder on brakes...

Bummer because I found the M system to be excellent performance wise, absolutely consistent, even when running hot enough to melt skin.