Bluish rotor discoloration: failed tech inspection? (pic added)
03-24-2006, 08:55 AM
#16
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If a rotor is 'cooked', it will be very hard on the tool that is used to turn it. Can get through a tool per rotor. If this is the case, then your tech inspector is correct.
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03-24-2006, 09:34 AM
#17
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The following article refers to hot spots damaging rotors through the formation of 'cementite'. I don't know if this is revealed by a blue discoloration (which I associate with overheating) or not. I have seen blued rotors on GT3s which were tracked with the OEM pads. They overheat and lose friction. The driver compensates by applying more pressure and the rotors get very hot.
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
http://www.stoptech.com/tech_info/wp...rakedisk.shtml
03-24-2006, 01:49 PM
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Originally Posted by Nordschleife
I believe that a series of extreme heat cycles can 'cook' the rotors. A strong blue hue is indicative of this. 'Cooked' rotors have undergone what might fairly be described as 'curing' or 'heat treatment'. In consequence, their behaviour under normal driving conditions is modified and their effective capacity for absorbing and releasingf heat is changed.
It is hard to tell from the photograph because of the lighting, reflections and lack of some external colour reference. However, the cracks do not seem great.
I would not dismiss your tech inspector's comments out of hand. My brake guy junks blued rotors faster than you can say 'HOW much?'
R+C
It is hard to tell from the photograph because of the lighting, reflections and lack of some external colour reference. However, the cracks do not seem great.
I would not dismiss your tech inspector's comments out of hand. My brake guy junks blued rotors faster than you can say 'HOW much?'
R+C
I'm running the stock brake pads.
Nordschleife, I see your point and am definitely not dismissing the inspector's comments. My C2's rotors with Pagid Oranges don't look anything like the GT3's after lots of track miles.
There's no doubt in my mind that cooling to the front of the street car needs improvement... I thought about Cup car ducts early on but went without them just to see what type of wear I'd be dealing with on this first set of rotors.
I guess now I know.
03-24-2006, 01:53 PM
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RJFab - get a set of Pagid RS 19 pads for your car. I suspected the OEM pads and those will certainly overheat on the track. The 19 is more rotor friendly than the Orange and squeals less too. They are pretty much standard equipment on track driven GT3's around here.
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Best,
03-24-2006, 05:23 PM
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Also to follow up with Bob's comments about new pads. Bed the pads in on the old rotors and THEN switch them over to the new Rotors.
Also as mentioned, BLEED your brakes. When bleeding make sure to crack open BOTH the front and back of all four calipers. Each caliper has TWO valves.
Also as mentioned, BLEED your brakes. When bleeding make sure to crack open BOTH the front and back of all four calipers. Each caliper has TWO valves.
03-25-2006, 01:13 AM
#22
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I had the blacks on my car (RS-14?) and they are notorious for being harsh on the rotors. I'm usually pretty hard on my brakes but these never skipped a bit...as for the OEM pads, let's just say Fred Flinstone had more heat resistance. I anticipate that had I used the RS-19's it would've been even better on my rotors...I would suggest go with the 19's, bed them carefully and your next set of rotors will fair even better and longer than these. I agree with RC, after seeing the pics, don't dismiss the discoloration as just simply nothing...that's as bad as I've ever seen on a street car.
03-25-2006, 01:22 AM
#23
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Randy, those rotors don't look 'failure' terrible, might get a second opinion. You probably will have to replace them in the near future.
Are RS 19 pads(or equivilent) avail for a C4S/TT?
Are RS 19 pads(or equivilent) avail for a C4S/TT?
03-25-2006, 01:46 AM
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Originally Posted by C4S Surgeon
Randy, those rotors don't look 'failure' terrible, might get a second opinion. You probably will have to replace them in the near future.
Are RS 19 pads(or equivilent) avail for a C4S/TT?
Are RS 19 pads(or equivilent) avail for a C4S/TT?
I'm thinking of swapping over to RS-19s on this set of rotors... what do you guys think of this? Any major incompatability issues between the stock pad and RS-19 compounds on the same set of rotors?
This set of rotors will be toast soon and I plan on going with the Cup rotor RS-19 combo thereafter.
I haven't had any issues swapping, back and forth even, Pagid oranges with stock C2 pads on the same set of rotors. However, I have no experience with the RS-19s.
Cheers
03-25-2006, 01:50 AM
#25
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Originally Posted by RJFabCab
...Any major incompatability issues between the stock pad and RS-19 compounds on the same set of rotors?...
Cheers
Cheers
03-25-2006, 01:50 AM
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Originally Posted by cosmos
Also to follow up with Bob's comments about new pads. Bed the pads in on the old rotors and THEN switch them over to the new Rotors.
Also as mentioned, BLEED your brakes. When bleeding make sure to crack open BOTH the front and back of all four calipers. Each caliper has TWO valves.
Also as mentioned, BLEED your brakes. When bleeding make sure to crack open BOTH the front and back of all four calipers. Each caliper has TWO valves.
I always do a full bleed... front and back valves... clutch, too!
Which reminds me... my Motive Bleeder sprung a leak in the handle assembly. POS!
03-25-2006, 01:51 AM
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Originally Posted by MJSpeed
None what so ever...plenty of people have done that.
Regarding the street... the car sees very little of it.
03-25-2006, 01:28 PM
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From the dealers perspective, and keeping in mind liability, I am sure they feel these rotors are toast. Many reasons, but mostly due to the fact dealers probably do not see 'tested' or 'thoroughly exploited'
rotors very often.
IMO, you can probably squeeze another event out of them. However, having a rotor come apart would be very costly..
rotors very often.IMO, you can probably squeeze another event out of them. However, having a rotor come apart would be very costly..
03-26-2006, 08:43 PM
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Originally Posted by RJFabCab
I'm thinking of swapping over to RS-19s on this set of rotors... what do you guys think of this? Any major incompatability issues between the stock pad and RS-19 compounds on the same set of rotors?
This set of rotors will be toast soon and I plan on going with the Cup rotor RS-19 combo thereafter.
Upon pad install, you'll probably want to zip tie your wear sensors out of the way, as the Pagids normally come without the ports for the wear sensor probes. It's also a safe bet (although not mandatory) to chamfer the front of your pads (file the leading edge of the pad to form an angle) so the pad can break in evenly.
Austin