trobarts

There has been much debate and discussion here over the two brake systems, and all of the press cars seem to have had the ceramic rotors. Does anyone know if there is a difference in stopping distance from 60 mph between the two? I recall in a slick back journal at one time, the comment was made that there was little if any difference in distance (in fact, the steels stopped shorter by 2 feet) but there were the other obvious differences such as less fade and benefits of unsprung weight with ceramics, etc. I have yet to see an aritcle in any place though about distance with the new gen. of PCCB vs. steels in spite of rather extensive research. I would be interested if any one has some info. TIA.

RamVA

Aside from less rotating mass in the PCCBs, there should be no difference. Distance is generally limited by tire grip, though or course influenced by the mass of the car and the rotating mass. The impact of these factors (based on the difference in mass between CC and steel) will be very, very small. That said, the reduced fade is very appealing.

multi21

Check out the "Autoweek Review of the 3" post this week. They had the GT3 stopping in 98' from 60-0 MPH with PCCB's. I don't know what the iron would be.

trobarts

M3Pete


Yes, I saw that. It is why I was interested as I have the steels (irons?). That is an amazing number but I was already stunned by the difference between my 996 turbo as far as the seat of the pants feel.

BobbyC

I have no scientific or measured basis for this other than my buttmeter...and a few good DE instructors buttmeters...on the track where it felt, and we did, brake later and later than points where cars with "big reds" steel would brake. If this helps any...

John Boggiano

In the real world, there's also the 'confidence factor' to consider. The PCCBs always have so much initial bite that you build real faith in their ability to stop you and, especially on track, that fact enables you to brake late.
I'll bet many people who have had their brakes fade occasionally (like me) never really quite get back to that very high trust factor using steels, and therfore always leave that little extra margin.

Nordschleife

The world braking record for a street car was set in a modified Pcar, with third party brakes. The rotors are iron, cast at SHW, the same firm used by PAG, amongst others, to a proprietary design of a braking specialist. The same specialist manufactured the calipers on his own in house machine tools from aerospace grade aluminium billets, they are monobloc six-piston designs. The hats are also manufactured in house from aerospace grade materials.

The benfits offered by PCCB brakes lie in their lack of rotating/unsprung mass.

It is inevitable that the best brakes for street cars will be produced by specialised engineering houses in Germany. Where else is there a nationwide high speed freeway system, a national obsession with powerful cars and the means to pay for the research and development required.

As it happens these brakes are also great for endurance racing.

The downside is that they are expensive. Interestingly, when I arrive at specialist manufacturers, there is usually an exodus from the workshops to inspect the brakes on the car I happen to be driving. German employers encourage their employees to come up with ideas. Engineering is still respected.

R+C

eclou

Now I want to see your brakes too!

Chris R.

I think you would be hard pressed to fade a set of GT3 brakes (steel) on the street. if you are tracking your car, invest in a good set of pagid rs29's for the front and rear and don't worry about it. Even in my little cayman S, I have never faded the brakes to the point where i could not stop or slow down properly. *note that my front calipers are the same as the REAR on a 996 GT3....
Yes, I'm fast so don;t give me the "get out of green and talk to us" jive.

PogueMoHone

[QUOTE=Chris R.] .... invest in a good set of pagid rs29's for the front and rear and don't worry about it .....QUOTE]

And a set of earplugs! They do work well, even if you are not fast.

They squeal like a cut pig!

cannga

Because of tire grip being the limiting factor, could it be that although there is no difference in 60-0 distance, there WILL be a difference in say, the 60-30 mph distance, or time, in favor of the PCCB?

Does anyone know if such a test has been done? I think it would be conclusive evidence that PCCB brakes "better" and the better "initial bite" a lot of PCCB users comment on could be proven.

Nordschleife

Why?

the amount of work done slowing from 60-30 is the square of the amount of work done slowing from 30-0? In order to record outstanding stopping figures, you need to get on the brakes as hard as possible as soon as possible. There is no 'improvement' in bite with ceramics compared to the best iron rotors.

The vast majority of drivers underbrake, having stumped up thousands of dollars more for PCCBs, they 'trust' them more and use more of their potential.

You are starting from the premise that PCCB brakes are 'better' than iron rotors. There is no empirical evidence to support that.

On of the problems with PCCBs is the amount of heat cycling they undergo. Iron naturally conducts heat. Ceramics however are an insulator, no whilst the PCCBs can wihstand a lot of heat, they also hang onto it for longer.

Try a test - heat your oven (stove) to 450°F, put a porcelain plate in it for 15 minutes to get it heated up. Now remove the plate and measure the surface temperature every 5 minutes. Repeat the test with a steel camping plate, iron would be better, but rather hard to find something of approximately equal mass.

R+C

PogueMoHone

Some things just come down to feel and the ceramics are just better feeling and more confidence building

R+C

Do you have an economic bias toward, or expertise in, steel brakes? You seem to hint towards an area of expertise and full disclosure would allow a reader to form a more objective opinion regarding your comments.

A number of expert race car drivers and engineers clearly state their bias for ceramics (in non public forums, mind you), so what do they know that you don't .... or vice versa?

Nordschleife

Colm

I am fortunate that I am completely indifferent as to what brakes I use - ceramic or iron. Incidentally brake rotors are iron not steel. All I require is that brakes work well and continue to work well.

I have bent the ears of enough people in the car business on the subject of brakes, and how crap their offering is, that I now do not have to pay for brake systems, their replacement or their maintenance. Brakes are really common sense, so its easy to become knowledgable enough on the subject that professionals listen to you.

You will notice that I studiously do not mention retail brands, only, from time to time, component suppliers.

As far as racing brakes are concerned, do not confuse Ceramic Composite rotors with Carbon rotors, entirely different. As it happens, there are very very few race cars with PCCB style rotors, so most race drivers are talking of their experience with carbon brakes which are wonderful, on the race track.

At meet the enthusiast owner events, of course the old professionals are going to say how great the brakes are, it wo9uld be ungracious not to. If I am demonstrating a car, I might do a rave about the brakes too, but I won't say anything untrue.

As far as the Supercup is concerned, the selection of the PCCBs is part of a spin campaign to rehabilitate a product with a somewhat tarnished reputation. The economics certainly do not stack up, but with prize money over $1,000,000 and 'subsidised' rotor prices, the team managers put up with the cost, but go and talk to the Ferrari Challenge guys who run similar rotors if you want a real shock. Longevity is rarely a requirement of brake rotors in the rtacing environment, 24 hours being sufficient. Road cars are more demanding in this respect.

I am not wholly opposed to PCCB rotors. However, I would not fit them unloess the ABS has been optimised for their use and that I was driven by a requirement to save weight wherever possibel. So I have specified them on one of my project cars, for their lack of weight, not their superios braking performance.


R+C

normank

Interestingly, when I arrive at specialist manufacturers, there is usually an exodus from the workshops to inspect the brakes on the car I happen to be driving. German employers encourage their employees to come up with ideas. Engineering is still respected.

Out of curiosity: What are you arriving for at these manufacturers? What do you do? I remember from an earlier encounter that you favor Napa Leather. Where does your automotive expertise and knowledge come from?