Carbon Ceramic Brakes & the Track

Mousecatcher seems spot on to me, although I also think F1 is in part heat tolerance due to the tiny wheels they must run and the fact that bigger brake ducts for iron rotors would also add drag, but I am no F1 engineer.

As for the TWS data, I can't help myself. I run faster than that in a Spec Miata (2:01s, sometime 2:00s and I want to say on the perfect day and lap I have a 1:59), so I am not sure the wear figures are that great a baseline.

I have driven on composite brakes and love the heat/fade tolerance, but I am not sold on them being worth it for track driving. I suspect that the mfg costs may eventually come down if the technology becomes more mature and widespread and I'll wait for that.

Every fast person I know saves the composite bits from their car and goes iron on track, unless they have (1) mega budget; or (2) required under rules (e.g. 430 Challenge)

 

Ouch...

 

I know - I am a jerk - everyone tells me so.

 

I said that was my average lap time. That includes cool-down laps, warm-up laps, laps in traffic, and laps in the rain.

Any time you want to show me the way around TWS in your Spec Miata, you just let me know. Bring your pink slip.

 

i can tell you first hand that this happens, and it is very expensive. the result of this is that i will NOT be tracking the cs again. perhaps i will recant on this and do so at 7/10ths.

besides the very real risk of inadvertent pebble damage, they also will last one tracking season if you do 6 hard track days - dealer mechanic's own words. well, at 6k per corner minimum vs about 500-1k for steel, i think i will do my tracking on steel brakes thanks very much.

i have also written about how some of the pro drivers have told me they dislike the ccm brakes and if given the choice, would not run them. it is a marketing ploy. thats all.

but the solution, that i have written about and gotten responses on in the challenge section, is to just get a challenge car (that has steel brakes) and track it. and leave your sensitive and expensive ccm equipped road cars back in the pits.

 

I have heard/read that carbon ceramic braking systems have a much smaller range of temperature where they operate optimally in regards to wear. If you are outside of that range, braking performance does not suffer much but longevity does. Anyone care to comment on that and whether that is true or false?

 

+1

Race cars are for race tracks. Street cars are for the street. makes sense to me

I dont see why people track there road ferraris or porsches lambos etc... cars that they care about if it has rock chips etc... if this is the case... stay in the parking lot. I can understand running a HPDE event and running around at say 7/10ths every great now and then, but you will still be shocked how much wear your car will pick up doing that.

With such great deals on 360c's i don't know why they are not more popular as "tracking a ferrari" seems to get more and more common around here.

In reality... but a spec miata...

 

It's true for the PCCB, Ferrari CCM, Corvette ZR-1 Ceramic rotors, and any other OEM "laminated" ceramic rotor that is made by Carbon SGL. In high heat/high temperature conditions, the friction surface (less than 1mm thick) de-laminates from the ceramic core casting. The ceramic core beneath the friction surface is very abrasive and destroys pads. It can delaminate in small pieces, degrading rotor effectiveness over time, or in certain cases, can delaminate catastrophically, becoming immediately unusable. I have one such PCCB rotor that I keep as a souveneir and conversation piece.

Some contributing factors to said high heat conditions: lack of brake cooling (no brake ducts); thin pads (less than 50% remaining); improper brake pads (carbon metallic and other hi-friction pads not specifically for carbon ceramic rotors); tapered pads (ironically caused by Brembo PCCB calipers, among others); emergency stops from very high speed (150 mph+) or while on-track (traffic avoidance, accident avoidance, red flags).

 

Just out of curiosity, is/was your porsche an early PCCB car. I heard, and never was able to follow that there was an alleged updated version on later cars such as 997s. What car was your experience based on? And please if you have any other knowledge or if I have gotten the question only half right... share with the class

 

Run for Pinks? OK, but it does not seem fair to run a Porsche Turbo with PCCM vs SM. Surely you don't need that kind of advantage. How about if I bring a Lotus Elise? I'll run stock rotors and calipers. And bring my title. Or I could bring a Viper - surely you are not afraid of a Viper? It has iron rotors, too.

 

I had Gen 1 PCCB rotors. Gen 2 came out in 2005. Porsche is currently on Gen 3 rotors for the GT2s and GT3s. No change in the chemistry or the construction. Just an update to the vent patterns. Others are still experiencing the same problem, and I still see the same heat fatigue symptoms on newer PCCB cars at the track.

 

what a complete waste of money then. To me its almost criminal.

 

I have no experience with carbon brakes, or professional racing, or even with serious amature racing But what i have seen is that factory brakes, (barring serious dedicated track stuff),do fine on the street but do not hold up under track use, even light track use with everything else stock.

I have seen unhappiness with stock brakes in every car specific thread from old cars to the F-40s when used on the track, Primarily because they are being pushed beyond their designed thermal limits --- pads and rotors needing to be replaced after a FEW track days, backing off because the fluid/pads are boiling/on fire.

Our street cars were never designed to change real track speed to hot air.

I have tracked speedsters, a pumped 914 and a ferrari, all with much better heat dissipators and been very happy.

In some specific applications, (primarily, it seems when money is absolutely no object, like real racing or F-1, you can engineer carbon to deal with it).

For the rest of us, Bigger cast iorn and better pads, (with perhaps a bit of additional air) wil suffice nicely.

My maximum overkill 308 brakes, (F-50 fronts and 360 rears), show almost no wear after tracking, were relatively cheap, and are bullet proof reliable.

It seems that trying to use bleeding edge technology is hugely expensive/maintenance intensive.

??
chris

 

I just weighed my 330 x 32 575M rotors (same size as F430) against my new Mov'it 396 x 36 CER rotors and each CER rotor weighed 6.4 lbs less (22.2 lbs vs 15.8 lbs). The 6 piston billet Mov'It calipers and pads (much larger than CCM pads) weighed 2.2 lbs more (10.8 lbs vs 13.0 lbs) than the OEM Brembo 4 piston calipers, for an overall savings of 4.4 lbs per front axle.

I have been trying to interest Mov'it in producing their solid carbon silicon carbide CER rotors and pads as direct replacements for the CCM parts, still using the monobloc Brembo calipers. They already do it for the PCCBs. Those rotors are far superior to the CCMs (and PCCBs) and will last much, much longer.

So far not much interest from Ferrari owners. Do not understand why. No more silly software telling you when to change your rotors. Just tell the DME the car has steel brakes. Their pads come with factory wear sensor wires, too.

Bob- Just saw your info on the CER brakes. What most people do not seem to realize is the CER rotors are a homogeneous solid of carbon silicon carbide vs a CCM rotor that has a CSC center and a thin layer of braking medium bonded to the CSC. Once the thin layer is gone, the rotors are shot. The solid CSC rotors are exceptionally tough and just do not wear, as your data shows. The rotors and pads are far superior to CCM and PCCB friction materials. They will prove to be real money savers compared to either CCM/PCCB or steel brakes in the long run and provide superior braking.

Taz
Terry Phillips
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These would interest me, if they could be used with stock calipers (and thus stock 18" wheels) on a 360. BTW, the weight savings of course is good, but I've been told that because the weight savings is so concentrated around the hub, saving weight with discs is not as significant as, say, losing the same amount of weight from the wheel rims. Of course it's all good and there are other reasons for CCBs or other carbon derivatives than just weight savings.

Another question, somewhat related to this topic. I'm curious about what, if any, are the proper bedding procedures for CCB or other carbon derivative discs? It's now well-accepted to bed iron discs, but do you do that with CCBs or other carbon discs as well?

 

N4S- Will ask, but I think the 330 x 28 mm rotors on your car may be too small (thin) to duplicate as CERs.

Bedding for street use on the CERs is not required. The brakes have gotten progressively better as I put miles on them.

Taz
Terry Phillips

 

Note on the weights on the brake components: F430 (and 360) rotors are actually 360 x 28 mm, not 360 x 32 mm like the Maranellos. Just looked in the F430 WSM and should have done that earlier. F430 front rotors would weigh less than Maranello rotors. Makes sense because the Maranellos are larger and front engined.

Taz
Terry Phillips

 

What you were told about weight savings applies mostly to iron rotor BBKs that use a larger rotor with an aluminum hat. The weight savings is primarily in the hat, which is closest to the hub (measured radially). The weight savings in ceramic rotors is in the disc, which is farther from the hub. The hats are usually stainless steel, which is heavier than the aluminum hats, but is an important insulator for your hubs and bearings. As you suggest, weight savings in the barrels of the wheels is better yet, being the largest diameter rotating masses on the car. Weight savings on any rotating mass is goodness^2. Likewise, weight savings on any un-sprung mass is about 10 times more valuable than equivalent sprung mass, in terms of suspension performance (Factor = sprung mass/un-sprung mass).

The full Movit CER kit comes with a set of pads pre-bedded to the rotors on Movit's brake dyno, and the pads are labeled for the rotor and face they are bedded to. For those who wear out the original pads (so far I am the only one to order replacement pads through MovitBrakesUSA), the pads come with bedding instructions, similar to other pads.

 

My CER rear rotors are 348mm x 28mm, same as PCCB rotors.

 

Bob- You are correct. My rear CERs will be 362 x 28 mm, so replacements for the OEM steel rotors are possible.

Taz
Terry Phillips