Rotor Failure
10-06-2013, 12:08 PM
#1
Le Mans Master
Thread Starter
Rotor Failure
I've run the DBA T3 4000 rotors this year on my 04 Z for the track. For the most part I've been satisfied with the longevity until this happened a few weeks ago at Pocono. The pads I use are Carbotech XP12s up front. I'm curious if anyone else has ever encountered the hat seperating from the ring on a one piece rotor. Also, the other side that didn't fail is developing a crack between the hat and ring.
10-06-2013, 01:12 PM
#4
Advanced
Member Since: Jan 2013
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
From the looks of the slotting, these rotors should have been cycled-out a while ago. There is practically no slotting left on the outer slots. How many track days on these rotors?
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life. I typically see these on the outer-edge of the cheap Chinese rotors I use for the track. I replace them as soon as I see a similar crack approach the outer edge. It is only a matter of time until you hear the familiar "tink" of the rotor cracking after paddocking following a track session.
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life. I typically see these on the outer-edge of the cheap Chinese rotors I use for the track. I replace them as soon as I see a similar crack approach the outer edge. It is only a matter of time until you hear the familiar "tink" of the rotor cracking after paddocking following a track session.
10-06-2013, 01:42 PM
#5
Drifting
Member Since: Dec 2005
Location: Dayton, OH
Posts: 1,822
Likes: 0
Received 0 Likes
on
0 Posts
From the looks of the slotting, these rotors should have been cycled-out a while ago. There is practically no slotting left on the outer slots. How many track days on these rotors?
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life.
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life.
This wasn't a failure of the manufacture.
This rotor was far beyond the point of replacement before it cracked.
Don't push it so far next time.
10-06-2013, 02:33 PM
#7
Le Mans Master
Thread Starter
From the looks of the slotting, these rotors should have been cycled-out a while ago. There is practically no slotting left on the outer slots. How many track days on these rotors?
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life. I typically see these on the outer-edge of the cheap Chinese rotors I use for the track. I replace them as soon as I see a similar crack approach the outer edge. It is only a matter of time until you hear the familiar "tink" of the rotor cracking after paddocking following a track session.
Additionally, I see stress cracks at the inner-edge of the rotors indicating that this rotor was at the end of it's life. I typically see these on the outer-edge of the cheap Chinese rotors I use for the track. I replace them as soon as I see a similar crack approach the outer edge. It is only a matter of time until you hear the familiar "tink" of the rotor cracking after paddocking following a track session.
Regarding the slots, that's pad material and or rotor wear filling them up and not wear on the ring. That's what I thought at first too until I scraped it ot with a screwdriver.
I also used the cheap Chinese rotors until this year. Typically they would "ping" late on the 2nd or early on the 3rd day. Just got tired of changing rotors at the track all the time
10-06-2013, 03:19 PM
#8
Advanced
Member Since: Jan 2013
Posts: 59
Likes: 0
Received 0 Likes
on
0 Posts
It was the 6th track day on them and happened on track. I forgot to add I also have the Quantum/DRM cooling setup.
Regarding the slots, that's pad material and or rotor wear filling them up and not wear on the ring. That's what I thought at first too until I scraped it ot with a screwdriver.
I also used the cheap Chinese rotors until this year. Typically they would "ping" late on the 2nd or early on the 3rd day. Just got tired of changing rotors at the track all the time
Regarding the slots, that's pad material and or rotor wear filling them up and not wear on the ring. That's what I thought at first too until I scraped it ot with a screwdriver.
I also used the cheap Chinese rotors until this year. Typically they would "ping" late on the 2nd or early on the 3rd day. Just got tired of changing rotors at the track all the time
10-06-2013, 06:21 PM
#9
Drifting
I was typically getting 5 track days out of my DBA4000's when I had the stock calipers, lines, cooling, and XP12 pads with SKF hubs. Then they would crack through.
10-06-2013, 06:23 PM
#10
Le Mans Master
Thread Starter
I find it hard to believe that there weren't any other signs that rotor failure was imminent. Typically it is spider cracking headed to the outer edge of the rotor. With this failure, I would expect similar signs toward the inner edge ( hub side). Either way, I can't imagine this happening "on track" without finding myself in a wall/barrier. Where/how exactly did this happen? Glad you and the vette are ok.
I'll know to check in the future for any cracking between the hat and the ring.
10-06-2013, 06:24 PM
#11
Le Mans Master
Thread Starter
10-06-2013, 06:51 PM
#12
Safety Car
That's a seriously worn out rotor. It probably should have been changed before you went to the track. Here's an article from a few years back. I've got a new brake rotor (brake disc) article coming out this month in Vintage Motorsport magazine.
One of the interesting facts about rotors is that because they're unsprung weight they need to be light. Then because they need to absorb a lot of heat they need to have a lot of steel. It's always a balancing act.
Richard Newton
One of the interesting facts about rotors is that because they're unsprung weight they need to be light. Then because they need to absorb a lot of heat they need to have a lot of steel. It's always a balancing act.
Richard Newton
Last edited by rfn026; 10-06-2013 at 06:52 PM. Reason: sp
10-06-2013, 10:07 PM
#14
Drifting
I disagree with comments implying it was your fault for not replacing the rotor sooner.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
10-06-2013, 10:12 PM
#15
Drifting
http://forums.corvetteforum.com/autocrossing-and-roadracing/2940073-dba-4000-rotor-serial-no-for-the-recall.html
do search using "DBA rotor recall" and you will see pictures similar to yours
do search using "DBA rotor recall" and you will see pictures similar to yours
10-06-2013, 10:26 PM
#17
Le Mans Master
Thread Starter
I disagree with comments implying it was your fault for not replacing the rotor sooner.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
10-06-2013, 11:26 PM
#18
Race Director
I disagree with comments implying it was your fault for not replacing the rotor sooner.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
You should contact DBA. If I remember correctly, they had a batch of rotors machined seriously wrong and had similar failures. A friend had same type of failure in T3 at Road America a few years ago. Rotor manufacturer paid out several thousand dollars to repair front end damage to his C6 Z06. They had a recall on all these rotors.
I would also call carbotech and see what they have to say about pad material clogging the groves. I thought it was not supposed to do that otherwise what is the point of the grooves?
10-07-2013, 12:43 PM
#19
Le Mans Master
10-07-2013, 12:45 PM
#20
Le Mans Master
I agree. Although they usually crack before wearing down that far sometimes rotors will last long enough for grooves to disappear. I can do that with my rear two piece rotors.
As far as cracking rotors goes. That is common. I have never seen this form of cracking though as displayed in the photos.