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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
I switched to the AP Racing Kit for front and rear. I got 13 days on the front rotors before I decided to replace them and 19 on the rears. The fronts had matching grooves on both sides of the rotor that worried me as far as minimum thickness and the rear rotors had started eating pads. Both sets of rotors were still above minimum weight but not by a lot.
As you near the min weight threshold of the rotor, or surpass it, pad wear is exacerbated due to the abrasiveness of the rotor face. we have witnessed a new set of pads get used up in less than 20 laps at COTA. On a new car, they will go 100 laps.
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Well, you guys schooled me on this. Looks like I will be replacing brakes with the AP system and save the new carbon rotors etc for resale down the road. I was sold a bill of goods on them for sure. I like the weight savings of the CCB's but for sure its not worth the price and its not going to make any difference for my level of driving on the track. Where do you recommend buying the AP set up for a reasonable price? If anyone has a link on that, I appreciate it. This has been a very good thread. Best to all, bob
Last edited by rsilver; 09-25-2017 at 01:25 PM.
Reason: another thought
As you near the min weight threshold of the rotor, or surpass it, pad wear is exacerbated due to the abrasiveness of the rotor face. we have witnessed a new set of pads get used up in less than 20 laps at COTA. On a new car, they will go 100 laps.
Agreed. I was advised early on to change pads when they got down to 3mm... allowing them to run right down results in faster rotor deterioration and just isn't cost effective. My rotors have been holding up very well.
When I changed pads at 3mm they looked like they could have given me another track day (maybe more)... but if they destroyed the rotors doing it then it just didn't make sense... so I changed them.
Others I know you run them down all the way seem to be wearing out rotors at a much faster pace than I.
Agreed. I was advised early on to change pads when they got down to 3mm... allowing them to run right down results in faster rotor deterioration and just isn't cost effective. My rotors have been holding up very well.
When I changed pads at 3mm they looked like they could have given me another track day (maybe more)... but if they destroyed the rotors doing it then it just didn't make sense... so I changed them.
Others I know you run them down all the way seem to be wearing out rotors at a much faster pace than I.
You are correct. Most dont know, but The achilles heel of the Z07 rotor is that while it can operate at elevated temperatures, the wear rate is increased.
The pad is a heat sink, and when you allow it to run down to nothing, that last few MMs of pad have accelerated wear on the rotor, AND the pad, due to heat.
Well, you guys schooled me on this. Looks like I will be replacing brakes with the AP system and save the new carbon rotors etc for resale down the road. I was sold a bill of goods on them for sure. I like the weight savings of the CCB's but for sure its not worth the price and its not going to make any difference for my level of driving on the track. Where do you recommend buying the AP set up for a reasonable price? If anyone has a link on that, I appreciate it. This has been a very good thread. Best to all, bob
I got mine right from Essex Parts but they are just a short drive down the road from me so I can call and get pads, fluids, spare parts withing a half hour. By the way keep your ceramic brake calipers/rotors/pads and reinstall them before you sell the car. That way if you want to you can sell the Essex kit to other track people unless you get another car that you can put it on.
I just pulled the Carbon Ceramics and swapped them for some Girodiscs, here are the numbers:
Drivers front minimum weight 6016 grams, weight after 5 track days 6135 grams
Passenger front minimum weight 5966 grams, weight after 5 track days 6075 grams
I will add the rears later in the week when I get to them
I found it odd that there is such a high variance in minimum weight on the oem Carbon Ceramic rotors - Rsilver mentioned rotors with 8002 grams min weight.
Btw - Giro disc fronts 12.93 KG. Approximately 2x the weight of my CC's.
Last edited by NiceGuySanti; 02-04-2018 at 06:52 PM.
I found it odd that there is such a high variance in minimum weight on the oem Carbon Ceramic rotors - Rsilver mentioned rotors with 8002 grams min weight..
I weighed some of mine a few months ago and put the weights in a thread. The weights below are all new rotors that I have stockpiled for the future.
Here's what I came up with.
Fronts:
Weight I got 6132g
Min weight on hat 6028g
Difference 104 grams
Weight I got 6068g
Min weight on hat 5962g
Difference 106 grams
Weight I got 6070g
Min weight on hat 5966g
Difference 104 grams
Weight I got 6079g
Min weight on hat 5982g
Difference 97 grams
Weight I got 6130g
Min weight on hat 6028g
Difference 102 grams
Weight I got 6015g
Min weight on hat 5918g
Difference 97 grams
Rears:
Weight I got 8137g
Min weight on hat 8062g
Difference 75 grams
Weight I got 8000g
Min weight on hat 7922g
Difference 78 grams
You can see that the 8kg rotors are the REAR ones. All the fronts are down in the 6kg range. So Rsilver must have been talking about rear rotors.
6,000 grams is about 13-1/4 pounds (some 211 ounces).
I've got a larger variance than you do from my heaviest to lightest, but I'll use your weights.
Your minimum weights are 50 grams different (about 1-3/4 ounce). With the minimum weight of around 6000 grams, the 50 gram difference is about 0.8%, which I don't think is significant at all, much less a "high variance".
My min weights overall from the heaviest to lightest are a little greater than yours, but I still consider it insignificant.
Bottom line - a couple ounces of difference is not much at all when the rotor weighs more than 13 pounds.
Interesting - assuming the difference between the minimum weight and the new weight of your front rotors is about 100 grams and that is the consumable part of the rotor, my rotors with about 100 grams of consumable material left are pretty "fresh" even after 5 track days.
Thanks for posting up that data.
Last edited by NiceGuySanti; 02-04-2018 at 09:30 PM.
[*]factory corvette team runs them (not apples to oranges, but iron is run by 99% of race cars out there)
.
...Factory corvette team is mandated to run steel by rule book...NASCAR use carburetors on their motors, maybe that's because they are superior to EFI?...I don't think so
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
Did you properly bedded the pads ?
50-60 stops make you sick to your stomach and the smell is really bad....
But it helps pad life and rotor life big time....
If you drive mainly on street afterwords, please do another bedding morning before track day and let all cool down...
BTW, pedal is going full soft and you will think brakes stop working durning bedding....
But do it, i got 6000 miles on my set and 4 track days.. also track day say nothing , number of miles and the track layout tell much much more...
My tracks are bad on brake/tire..... so 4 track days is ok aprox 9 full tank of fuel... roughly 900 miles track duty
so for track, for all the people not on a z07 package... do you have to change from OEM rotors? using any special fluids.. recommended pads for a car doing track work ?
...Factory corvette team is mandated to run steel by rule book...NASCAR use carburetors on their motors, maybe that's because they are superior to EFI?...I don't think so
so what steel rotors are people using as replacments for the z07 package? same calipers as the non z07 package? and a recommended track pad for those rotors (like GOOD track pads that can take abuse)
Im about to buy a z07 package grand sport and will probably switch off the CC rotors
so what steel rotors are people using as replacments for the z07 package? same calipers as the non z07 package? and a recommended track pad for those rotors (like GOOD track pads that can take abuse)
Im about to buy a z07 package grand sport and will probably switch off the CC rotors
I agree. Using this same set up. Only have one weekend on them so not ready to review.
Will ad, you can keep the OEM calipers on the car.
The backing plate on the GTR is the same as the fronts so we are able to buy the thicker GTR pads (and have enough clearance to install).
One con, I added 28 pounds of rotor weight to the car. And I notice the difference.
It will take you quite some time to go through those rotors on the street. It’s not as if there is a lot of delta between brand new and min weight. They are probably at 50% which means there is a ton of street miles on them, even if you are an aggressive driver or you push the car on some twisties.
09-25-2017, 10:54 AM
