rsilver

I have searched this and I believe the only way to determine if a carbon ceramic rotor is worn out is to weigh it? (PITA and time consuming) or measure the thickness? I saw a min thickness measurement on the rotor of 1.24 inches and I measured mine at
1.26. So by that measurement it is worn out, but the rotor is smooth on the friction surface but I did notice one vacant channel described in the specs I posted on chipped rear rotor thread.
Min weight was 8002 grams
but I don't have a scale that will measure that. So, in effect you have to pull all the rotors and weigh them on a special scale to make sure? The track guys with CCB's must have a simpler way to know when to replace them. The scales are not that expensive but its going to take a lot of time.
Is there another way to know if they are ready for replacement?

topmover

The book says you have to weigh them. Not saying my method is best however I replace them when the delamination has gotten to the point where the rotors start to chew up the pads.

Bill Dearborn

The weight can drop faster than the thickness. Just buy a cheap postal scale that can handle the max weight (mine can handle up to 70 lbs). Before you weigh the rotor make sure you clean all of the dust out of it by blowing it out or washing it out.

Weight is the primary measure as they tend to degrade from the inside Vs the outside. However, you need to measure both. My front rotors were very close to minimum weight and had grooves in them that made them thinner than the minimum thickness.

Bill

rsilver

That makes a lot of sense. If no grooves in the rotor, then min thickness might be somewhat accurate but I guess weight is the best measurement. I want to make sure they are ok and in spec, don't want to go 140mph down the straight and not be able to make the turn at the end because of poor braking. thanks for the comments.

c7jim

And how long do your rotors last before you start to see delamination of the rotors
i have less than 9000 miles and mine are pitted and delaminating to the point I wore through 75 % of new front brake pads in a single track day
now I'm switching to iron

topmover

Back in 2011/12 I'd get about 10 track days on the fronts with a few hundred street miles mixed in.

Last year I picked up a lightly used 2013 ZR1 which had 4000 street miles before I took it to the track. I had to replace those front rotors after 6 track days.

I have 5 track days on my C7 GS and if I had to guess they will likely make it for another 3 maybe 4 days.

Questions and results about these brakes are all over the board. Many say if you're getting poor results surely you're not breaking the pads/rotors in properly etc. etc.

I'd expect that better cooling would help but I just think at the end of the day driving style has more to do with it than anything.

One thing for certain if you track a lot they're not a cheap option.

B's Z06

How long will the CCB's last without tracking the car?

rsilver

Hi Bill, I wanted to update this thread regarding wear and weight on CC rotors. I weighed my new rear rotor with a scale sensitivity of +- 1 gram. New the weight was 8066 grams VS a minimum spec stamped on the rotor of 7992 grams. My old rotor which looked fine weighed 8088 grams with a minimum weight of 8002 grams. I was surprised, I thought there would be a great weight difference. I read somewhere that someone went through 200grams on a single track day. I don't think there is that much material to account for that much weight loss. Since the thickness difference between worn and new rotors is measured in micro meters, its is not practical to measure that. It also seems like there is only approx 100grams+- on new ones. I found similar results when comparing weight on new front rotors vs worn ones as well.
FWIW I talked to the Ferrari race shop guys to see if they had the measurement device from Germany that measures rotor wear. Its $6500 and the dealer deal might have the tool, but the Ferrari racing shop did not and they determined wear based on concentric grooves on the rotors. I posted GM's CC rotor tech inspection which says basically the same. All things considered, I think visual inspection is the way to go. I did remove all the dirt from the holes in the old rotors, washed them, dried them, cleaned any other material I could find before I weighted them. So I am close. I have at least 15 track days plus 5K street miles on them and they are still good. For sure, I was not on the brakes when I started tracking the car as I was taking it easy when I started tracking at a novice level with some track experience. I am sure they would wear quicker with a more advanced driver, but most say 6 to 10 track days. Mine are still good to this point, and the only reason I ordered a new one was because Discount chipped one of the rear ones and replaced it with a new one, so I got the opportunity to measure new VS worn. I also bought new front ones ( found a reasonable good deal) but I have not installed yet based on above. Anyway, hopes this help anyone wondering about this issue. Best, bob

GSpeed

The reason you need to weigh them is due to the way they wear. They are manufactured by "carbon vane (sp?) deposition" where a dirty gas is flowed through the rotor, and the carbon is built up.

As the rotor wears, the carbon is burned off, and structural integrity is decreased.

We have found like mentioned previously, that you can run the rotor to the point where it is delaminating the face, and pad wear has gone through the roof. At this point, they are several grams below min weight.

hemmerman

I would highly wreck a mend you not do that.!!! your car and mine with CC brakes from the factory was designed and built for that brake assembly DO NOT CHANGE IT I know people that have done it.. believe me my life and i assume yours is worth more than few hundred dollars.. I am a 30+ year worker in a GM assembly plant near Bowling Green. Just saying

Warp Factor

Then why do so many people who have switched to iron for track use seem to be quite satisfied?

And it's a lot more than a few hundred dollars! The CC rotors don't last very long under hard track use. Have you checked replacement prices?

cdh027

Id like to know the answer to this as well?

Warp Factor

Mild street use? Just about forever, from what I've read (as long as they aren't chipped during a tire change or something).

hemmerman

I choose to have the Superior brakes on my car and if he wants to change then at least i can say "he's been warned" FLAME ON WARP FACTOR.

GSpeed

The Pros of Carbon brakes:

• Weight
• lack of noise
• OEM fitment
• OEM balance
• parts available everywhere

The Cons of Carbon brakes:

• replacement cost
• pad thickness
• ease of damage when servicing the car

Pros of Swapping to Iron brakes

• Replacement cost is cheap, comparatively speaking
• tunability of brake system
• thick pads
• compound variety
• ability to "float the rotor" in pad knockback scenarios

Cons of Iron brakes

• rotor weighs more than OEM, caliper weighs less
• not stock
• heavier wallet due to cash surplus
• squeaky brakes if run on the street (You can buy street pads too)
• factory corvette team runs them (not apples to oranges, but iron is run by 99% of race cars out there)

This vette we equipped with AP Radi-Cal iron brakes, and have not looked back.

rsilver

Great Video! Great summary of Ceramic vs iron brakes.
Thanks, bob

Warp Factor

With all due(?) respect, you've stated that you're an assembly worker at a GM plant. That's really cool and all, but how much do you know about racing? And do you even own a C7 ZO6?

ASTROCREEP

No flames here. You gave a warning but with no justification other than your work credentials.

Please explain why a life would be in danger for switching to iron rotors on a car that came with a CC brake assembly.

The kits that I have seen (AP) for this swap is a complete brake assembly designed to work together. Including iron rotors, pads and caliper.

I'm not seeing a safety issue here. Performance/cost issue but not safety.

AVETTE

I got my Z07 in October of last year. Was very excited as primary purpose of the car was to do HPDE days. I knew the CCB's were more expensive but told the OUTRIGHT LIE that they 'last longer'. I was coming from a z51 stingray. The stock pads which wholesale for $1200 dollars approx lasted me all of 3 track days and I am an intermediate level driver. After burning through 3 sets of pads in mind numbing time, then the dealer started talking about needing to replace the rotors, I said

I AM DONE... F this...

Went with the same company the C7R race team uses

AP RACING endurance kit, brakes just as well, costs less than replacing OEM garbage, front pads are an astounding 25 mm thick, 7 track days so far and lots of pad left!!! Rotors are way way cheaper to replace, ditto with the pads

I have no affiliation with them, MANY of us track guys have dumped the CCB and Porsche guys who seriously track (first thing they do is take of the CCB to reinstall when they sell the car

I was sooooooooo disappointed as I was sold a bill of goods regarding the CCB system. A few guys have claimed to get better life out of the pads but LOTS of us have dumped them

I could not afford to do the HPDE days with all the other associated costs not to mention what a pain in the *** changing the pads after such a short time over and over at the track...

Went to the AP Racing set up and couldn't be happier. You should know the AP Kit does make noise (some pad squeal) as most true track brake kits do, but that is a small trade off to not waste your time on the paddock changing pads and emptying your wallet like there is no tomorrow... Just my .02 cents, good luck
______________

Robert R1

The CCB's wear fast especially as you get faster. As the rotors wear, they wear through pads even faster which in turn wears the rotors faster. As my rotors were wearing down, I was down to replacing pads every 1.5trackday or so.