Braking Distance CCB vs Stock

[MasterP]

Originally Posted by Dalko43

And how did you make that determination?

Because I can point you to various reviews where journalists drove a CCB-fitted M3/M4 and noticed no degradation in brake performance over numerous laps.

It's a known fact that CCB's need MORE thermal management than steel. Yes, they are lighter, and are more fade resistant. Braking is just energy transfer from kinetic to thermal. CCB's has higher threshold than steel, but at that point you are talking about a significant increase in heat. Without proper ventilation and cooling the rotors will oxidize and lose mass. CCB rotors do not show normal wear like steel rotors and must be weighed. There's plenty of information about this out there. While it may be "new" to BMW it's not new to P cars, F Cars, and the ZR1 - all which have a lot of cooling and diverting to keep the brakes cool. There's been instances during the ZR1's development where the brakes actually caught fire.

CCB's giving you greater performance potential, but you're still limited by the pads. The car as it is when you drive off the lot does not have special duty pads where you can just jump on the track. The Journalist opinions you covet had already made complaints that they were surprised about the brakes fading in the M5/M6. Granted those cars are significantly heavier, but BMW ships the cars with "OK" pads that suit street performance. Brake pads can decide initial bite, feel, and all those other things we talk about with brakes - but they're also thermal tools. If you go out with street pads sure they may perform fine for a few 20 minutes sessions (when's the last time a journo has tracked a road car the same duration as you do for a DE?) but then they will wear more rapidly then a proper CCB "Track" Pad that can take higher amounts of heat. You still need to find a decent track composition for track duty. Endless W007 and W006 are popular for CCB rotors.

And "Numerous laps" is what? At a large circuit going balls out 20 minutes could be 7-8 laps. Journalists track review of a press vehicle on a press day isn't the same as a person taking their car out to a DE where regular people go out with only the car they drove in on hoping the brake fluid and pads last all day. Journalists get one session before moving along to Q&A and cocktails. Maybe one more if You're Chris Harris. If you've ever been to a BMW Media day they bring pallets of Michelin tires, technicians, and yup - brake pads for the journalists and VIPS. So their experience will be far different from yours.

[FTS]

[Dalko43]

Originally Posted by TrakBch

It's a known fact that CCB's need MORE thermal management than steel. Yes, they are lighter, and are more fade resistant. Braking is just energy transfer from kinetic to thermal. CCB's has higher threshold than steel, but at that point you are talking about a significant increase in heat. Without proper ventilation and cooling the rotors will oxidize and lose mass. CCB rotors do not show normal wear like steel rotors and must be weighed. There's plenty of information about this out there. While it may be "new" to BMW it's not new to P cars, F Cars, and the ZR1 - all which have a lot of cooling and diverting to keep the brakes cool. There's been instances during the ZR1's development where the brakes actually caught fire.

CCB's giving you greater performance potential, but you're still limited by the pads. The car as it is when you drive off the lot does not have special duty pads where you can just jump on the track. The Journalist opinions you covet had already made complaints that they were surprised about the brakes fading in the M5/M6. Granted those cars are significantly heavier, but BMW ships the cars with "OK" pads that suit street performance. Brake pads can decide initial bite, feel, and all those other things we talk about with brakes - but they're also thermal tools. If you go out with street pads sure they may perform fine for a few 20 minutes sessions (when's the last time a journo has tracked a road car the same duration as you do for a DE?) but then they will wear more rapidly then a proper CCB "Track" Pad that can take higher amounts of heat. You still need to find a decent track composition for track duty. Endless W007 and W006 are popular for CCB rotors.

And "Numerous laps" is what? At a large circuit going balls out 20 minutes could be 7-8 laps. Journalists track review of a press vehicle on a press day isn't the same as a person taking their car out to a DE where regular people go out with only the car they drove in on hoping the brake fluid and pads last all day. Journalists get one session before moving along to Q&A and cocktails. Maybe one more if You're Chris Harris. If you've ever been to a BMW Media day they bring pallets of Michelin tires, technicians, and yup - brake pads for the journalists and VIPS. So their experience will be far different from yours.

You're talking very much in the hypothetical sense, and though you have some detailed info about Carbon Ceramic brakes in general, I still have yet to hear your answer in regards to my original question:

How are you able to determine that the CCB's on the M4 lack sufficient cooling? Do you have track experience with that car and that brake setup? Should we assume that every single review of the M4 with CCB option is a staged performance by BMW with (non-standard pads and fluids)?

[Spinny02]

M5 distances have been the same on independent test but the feel and confidence on the track is a noticeable difference + almost no brake dust =). I would not trade mine.

[CanAutM3]

Originally Posted by Dalko43

We still don't have empirical evidence which shows how much more breaking performance/endurance the CCB option offers, or doesn't offer, over the base brakes...that's why I am anxious for new owners/vendors to conduct long-term performance tests.

I guess we'll have to wait and see. I was not willing to take that $10k bet with so little winning odds though

Originally Posted by Dalko43

Also, I didn't own the E9x M3, but I read about plenty of E9x M3 owners who were also track junkies...many of them claimed that the stock brakes were inadequate for long-term tracking. Many of them upgraded their brake systems, either pads and steel lines or a BBK kit.

Though the M3 has always been a street car with track performance in mind, this car has never been a 100% track car out of the box.

On every post, I always said track pads were needed on the E9X for any serious tracking.

I don't think that the E9X is in dire need for a BBK. I have driven quite a few very fast tracks (135+mph) with heavy brakng, and never had an issue.

While the need for a BBK on the E9X may be track dependent, it most certainly is very driver dependent. I see a lot of intermediate/advanced students overwork their brakes. Just recently, I saw an advanced student fry the front pads of his Brembo BBK on his E92. On the same day, I had no issues with my stock setup with PF08s, yet I lap 4 seconds faster than he does. Further, tracking with DSC or MDM activated will definitely kill your brakes.

[M4TW]

It would be nice if one of the many auto rags trolling the internet picked up on this as a comparo idea. They could test the BMW, Porsche (and others) CCB's vs their stock offerings.

We are long on opinions and short on facts here.

[CanAutM3]

Originally Posted by M4TW

It would be nice if one of the many auto rags trolling the internet picked up on this as a comparo idea. They could test the BMW, Porsche (and others) CCB's vs their stock offerings.

We are long on opinions and short on facts here.

Car & Driver did a brake comparo test a little while back. Both, a 911 with the PCCB and one with the base iron discs were included in the test. See here.

Car & Driver

The 911 with the PCCB system performed about the same as the other 911 and the Vette. The average stopping distances of the two 911s were within a foot of each other (305 feet), not surprising since both cars were wearing the same tires. The conclusion: PCCB buyers enjoy a 37-pound weight savings but not necessarily more robust brakes.

[M4TW]

Originally Posted by CanAutM3

Car & Driver did a brake comparo test a little while back. Both, a 911 with the PCCB and one with the base iron discs were included in the test. See here.

Thanks for the flashback. Of course I meant a comparison that included the BMW M3/4 systems, was specific to the issue at hand, and included more parameters than fade resistance.

[CanAutM3]

Originally Posted by M4TW

Thanks for the flashback. Of course I meant a comparison that included the BMW M3/4 systems, was specific to the issue at hand, and included more parameters than fade resistance.

You did mention Porsche in your post, the article answers that part .

It will be interesting to see a comparo between the M3/4 brake systems. However, I doubt that we will see one with the iron rotors paired with track pads. That is the one that really matters to me.

The article does discuss pedal feel, travel and force, but really what else is there to discuss in terms of a brake system performance besides distance and fade ?

[M4TW]

Originally Posted by CanAutM3

You did mention Porsche in your post, the article answers that part .

It will be interesting to see a comparo between the M3/4 brake systems. However, I doubt that we will see one with the iron rotors paired with track pads. That is the one that really matters to me.

The article does discuss pedal feel, travel and force, but really what else is there to discuss in terms of a brake system performance besides distance and fade ?

You are right.

The comparison would be between ceramics vs. stock as that is what would be of maximum relevance to buyers pondering the option. I mentioned Porsche because they offer the option. But they aren't the only ones. We also can't conclude that the same delta (or lack of one) exists between the Porsche systems and BMW's.

Areas that could be measured/compared are:

1. Stopping distance/fade;
2. Consistency;
3. Wear;
4. Cost (with long term considerations);
5. Acceleration;
6. Lap times; and
7. Driving impressions/pedal feel.

[CanAutM3]

Originally Posted by M4TW

The comparison would be between ceramics vs. stock as that is what would be of maximum relevance to buyers pondering the option.

Would it?

Folks who only drive their M3/4 on the street will most likely never reach the limit of the stock iron rotor setup, so the CCB option is an overkill anyway (from a braking performance point of view).

[M4TW]

Maximum relevance (i.e. interest) to Joe Reader who wants to know what to hypothetically (in most cases) order from the factory.

[Dalko43]

Originally Posted by CanAutM3

It will be interesting to see a comparo between the M3/4 brake systems. However, I doubt that we will see one with the iron rotors paired with track pads. That is the one that really matters to me.

The article does discuss pedal feel, travel and force, but really what else is there to discuss in terms of a brake system performance besides distance and fade ?

I think we are missing the point of CCB's here. No one should be buying them for necessarily a shorter stopping distance or firmer pedal feel. Several reviewers have tested those aspects of the M4's CCB and have noticed little, if any, improvement over the stock setup.

The whole point of CCB is increased resistance to heat buildup and fade. The pedal may lose its sharpness after repeated lapping (several journalists have noted just that), but the stopping power has remained consistent. That is important to many buyers, especially if they are considering use the car for track days.

The whole issue with comparing stock brakes with upgraded track pads applies to CCB setup as well...what's more relevant is a comparison of stock iron rotors w/ brakes vs CCB's in terms of brake fade and heat resistance.

[CanAutM3]

Originally Posted by Dalko43

I think we are missing the point of CCB's here. No one should be buying them for necessarily a shorter stopping distance or firmer pedal feel. Several reviewers have tested those aspects of the M4's CCB and have noticed little, if any, improvement over the stock setup.

The whole point of CCB is increased resistance to heat buildup and fade. The pedal may lose its sharpness after repeated lapping (several journalists have noted just that), but the stopping power has remained consistent. That is important to many buyers, especially if they are considering use the car for track days.

We are not missing the point at all. Fade resistance (heat build-up) has been one of the main points of discussion here. However, do look at the chart from Car & Driver I posted earlier. On the 911, the iron rotors resisted fade just as well as PCCB. If you look at the second chart below, you will see that the PCCB were less consistent than the irons with varying pedal travel from one stop to the other.

Originally Posted by Dalko43

The whole issue with comparing stock brakes with upgraded track pads applies to CCB setup as well...what's more relevant is a comparison of stock iron rotors w/ brakes vs CCB's in terms of brake fade and heat resistance.

If one needs to use track pads on the CCB, it defeats one the main benefits of the CCB: going straight from street to track.

Karussel's experience indicates that the iron rotors, even with the stock pads, performed very well for track duty. But I agree, stock for stock, the CCB will likely have a better resistance to fade. However, for the track junkies such as myself, the cost of the CCB is just prohibitive for frequent track use. Based on my experience with my E92, I am convinced that the iron rotors with track pads will perform perfectly at the track. The huge cost of the CCB is simply not worth it TO ME. For that cost, I am willing to take the extra 30 minutes to swap pads.

[M4TW]

Not that this proves anything, just thought it was cool to see.(190,000 km for fronts):

[gthal]

Originally Posted by M4TW

Not that this proves anything, just thought it was cool to see.(190,000 km for fronts):

Man, what did you do to the front pads to wear an extra 60,000km off them already

[Dalko43]

Originally Posted by CanAutM3

We are not missing the point at all. Fade resistance (heat build-up) has been one of the main points of discussion here. However, do look at the chart from Car & Driver I posted earlier. On the 911, the iron rotors resisted fade just as well as PCCB. If you look at the second chart below, you will see that the PCCB were less consistent than the irons with varying pedal travel from one stop to the other.

You have been focusing quite a lot on pedal travel and stopping distances, which I think are irrelevant to the CCB option. What I mean by that, is CCB's are designed to provide good/short braking distances, but they don't necessarily offer an advantage over high performance brakes and iron rotors in that regard. Honestly pedal travel, depending on the brake setup, can be trivial to braking in general. Many reviewers have noted that though the M4 (with CCB option) experiences progressively longer pedal travel during repeated laps, the braking performance remains consistent.

Also, we are not discussing the Porsche's PCCB option, we are discussing the M4's CCB option. And while I'm sure there are similarities between the 2 setups's, I would like to see some actual testing of the M4's CCB's rather than transpose the Porsche's performance to the BMW's capability sheet.

Originally Posted by CanAutM3

If one needs to use track pads on the CCB, it defeats one the main benefits of the CCB: going straight from street to track.

Seeing as we are still lacking empirical evidence, it's too soon to say how sufficient or inadequate the stock pads are with the M4's CCB option. But even if they provide decent performance and endurance, the aftermarket will likely come up with a pad that provides even better performance, just like with everything else BMW..that's what I meant by my comment.

I get that you don't want/like the CCB option, but you seem to be jumping to conclusions and doing everything in your power to discredit their performance and advantages. Just let the reviewers do their work and we'll see their true performance, or lack thereof.

[Dalko43]

Originally Posted by CanAutM3

We are not missing the point at all. Fade resistance (heat build-up) has been one of the main points of discussion here. However, do look at the chart from Car & Driver I posted earlier. On the 911, the iron rotors resisted fade just as well as PCCB. If you look at the second chart below, you will see that the PCCB were less consistent than the irons with varying pedal travel from one stop to the other.



If one needs to use track pads on the CCB, it defeats one the main benefits of the CCB: going straight from street to track.

Karussel's experience indicates that the iron rotors, even with the stock pads, performed very well for track duty. But I agree, stock for stock, the CCB will likely have a better resistance to fade. However, for the track junkies such as myself, the cost of the CCB is just prohibitive for frequent track use. Based on my experience with my E92, I am convinced that the iron rotors with track pads will perform perfectly at the track. The huge cost of the CCB is simply not worth it TO ME. For that cost, I am willing to take the extra 30 minutes to swap pads.

Also, where did you get that chart from? I couldn't find it on the Car And Driver website.

[M4TW]

Originally Posted by Dalko43

Also, where did you get that chart from? I couldn't find it on the Car And Driver website.

He posted the link above.

www.caranddriver.com/features/the-power-to-stop

[M4TW]

Originally Posted by Dalko43

I get that you don't want/like the CCB option, but you seem to be jumping to conclusions and doing everything in your power to discredit their performance and advantages. Just let the reviewers do their work and we'll see their true performance, or lack thereof.

I think CanAutM3 will argue that he stopped on his position after careful consideration and has not faded from it since.

[CanAutM3]

Originally Posted by M4TW

I think CanAutM3 will argue that he stopped on his position after careful consideration and has not faded from it since.

[CanAutM3]

Originally Posted by Dalko43

You have been focusing quite a lot on pedal travel and stopping distances, which I think are irrelevant to the CCB option. What I mean by that, is CCB's are designed to provide good/short braking distances, but they don't necessarily offer an advantage over high performance brakes and iron rotors in that regard. Honestly pedal travel, depending on the brake setup, can be trivial to braking in general. Many reviewers have noted that though the M4 (with CCB option) experiences progressively longer pedal travel during repeated laps, the braking performance remains consistent.

Also, we are not discussing the Porsche's PCCB option, we are discussing the M4's CCB option. And while I'm sure there are similarities between the 2 setups's, I would like to see some actual testing of the M4's CCB's rather than transpose the Porsche's performance to the BMW's capability sheet.



Seeing as we are still lacking empirical evidence, it's too soon to say how sufficient or inadequate the stock pads are with the M4's CCB option. But even if they provide decent performance and endurance, the aftermarket will likely come up with a pad that provides even better performance, just like with everything else BMW..that's what I meant by my comment.

I get that you don't want/like the CCB option, but you seem to be jumping to conclusions and doing everything in your power to discredit their performance and advantages. Just let the reviewers do their work and we'll see their true performance, or lack thereof.

You however, are on the other side of the spectrum trying to justify the CCB no matter what.

If you read my many posts in the various threads on the topic, I have always recognized the benefits of the CCB. However, it is important to be realistic on what those benefits are. I have always argued that those benefits are not worth the cost TO ME.

I have discussed all aspects of brake performance here. Starting with braking distances, resistance to fade and then feel and consistency. I was only responding to your arguments trying to justify the CCB.

I had to make my decision to opt or not for the CCB before any tests were available. So I had to make my analysis with what facts and information was at hand. For instance, the experience from Porsche owners on the PCCB is a good reference. I came to the conclusion that the benefits of the CCB were not worth the cost to me. I might be proven wrong when actual test results come out, but I seriously doubt so.

If they are worth it to you, get them. As I said many times before, options are a very personal thing, there are no right or wrong answers. I got the LED headlights just because I find they look good.