Another cracking rotor thread.
11-15-2008, 04:51 PM
#1
Le Mans Master
Thread Starter
Another cracking rotor thread.
Here's a couple of pictures from my '03 ZO6. The RF rotor has some surface cracking, the worst being about a 1/2" long. The LF has some pretty serious heat spots, but no cracking. I'm still on the stock rotors with Carbotech pads (8/10). How bad can the cracks get before it's time to swap out the rotors? Sorry for the bad pics, but it's the best I can do with the POS camera I have.
11-15-2008, 06:51 PM
#2
Race Director
I've been going by the rule that if I can catch the crack with my fingernail, I toss the rotor. I feel it's safer, less wear on the pad, and much less brake shudder, to just pitch them then. Recent pic of a crack, it was small yet but caused the front end to really shudder under braking.
11-15-2008, 08:10 PM
#4
Racer
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Don't want to replace rotors daily? STOP TECH, I get almost a whole season on one set of rotors with Road America as my home track (8+ events a year there alone). And no I am not easy on the brakes!
11-15-2008, 10:41 PM
#5
Racer
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My GTO's front rotors after five track days (HT-10 and DTC-60 pads). I think
these are the same 2-pot PBR calipers and rotors as are used on the OE C5:
I have a new set, but if these ones feel OK during the next bed-in, I'll
use them - just beat the snot out of them.
these are the same 2-pot PBR calipers and rotors as are used on the OE C5:
I have a new set, but if these ones feel OK during the next bed-in, I'll
use them - just beat the snot out of them.
11-16-2008, 12:12 AM
#7
Racer
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It does look pretty bad, doesn't it. Maybe some Zaino will fix it?
All right, I'll use the new ones, see how the above look after turning. They're
still >2mm above minimum.
Unfortunately GTO front rotors can't really be had for less than $200
a set, and they're the nasty ones. No NAPA cheapies for us.
All right, I'll use the new ones, see how the above look after turning. They're
still >2mm above minimum.
Unfortunately GTO front rotors can't really be had for less than $200
a set, and they're the nasty ones. No NAPA cheapies for us.
11-16-2008, 12:15 AM
#8
Melting Slicks
It does look pretty bad, doesn't it. Maybe some Zaino will fix it?
All right, I'll use the new ones, see how the above look after turning. They're
still >2mm above minimum.
Unfortunately GTO front rotors can't really be had for less than $200
a set, and they're the nasty ones. No NAPA cheapies for us.
All right, I'll use the new ones, see how the above look after turning. They're
still >2mm above minimum.
Unfortunately GTO front rotors can't really be had for less than $200
a set, and they're the nasty ones. No NAPA cheapies for us.
sucks that there are no cheapies for the GTO. might be worth looking into a two piece floating setup.
11-16-2008, 12:17 AM
#9
Melting Slicks
11-16-2008, 12:32 AM
#10
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hm, are you sure? The cracks are quite a bit narrower than they appear in that
photo. I'll give it a go anyway, if only to find out how deep they go..
Yeah. I've been trying to avoid aftermarket brakes because few of them
will fit inside a 17" wheel, and I have 4x17x9.5" vette wheels in my plans.
For most of the above rotor's life I didn't have ducting. I'm hoping that keeping
peak temperatures down will help extend their life.
photo. I'll give it a go anyway, if only to find out how deep they go..
will fit inside a 17" wheel, and I have 4x17x9.5" vette wheels in my plans.
For most of the above rotor's life I didn't have ducting. I'm hoping that keeping
peak temperatures down will help extend their life.
The 05/06 uses larger rotors and they're
11-16-2008, 05:06 AM
#13
Le Mans Master
hm, are you sure? The cracks are quite a bit narrower than they appear in that
photo. I'll give it a go anyway, if only to find out how deep they go..
Yeah. I've been trying to avoid aftermarket brakes because few of them
will fit inside a 17" wheel, and I have 4x17x9.5" vette wheels in my plans.
For most of the above rotor's life I didn't have ducting. I'm hoping that keeping
peak temperatures down will help extend their life.
photo. I'll give it a go anyway, if only to find out how deep they go..
Yeah. I've been trying to avoid aftermarket brakes because few of them
will fit inside a 17" wheel, and I have 4x17x9.5" vette wheels in my plans.
For most of the above rotor's life I didn't have ducting. I'm hoping that keeping
peak temperatures down will help extend their life.
- my wife has an 05 GTO?
11-16-2008, 05:21 AM
#14
Racer
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275mm r-comps all round.
With 56mm offsets the rears will bolt right up (my street rears are 285mm on
54mm offset CCWs, so all the fender grinding has been done).
For the fronts I'll use a 19mm adapter and will push the coilover 12mm
inboard with an eccentric bushing at the top and by extending and
redrilling the wheel mounting plates at the bottom. Might need to step up
to a 100mm 750lb spring so the coilover adjustment collar clears the tire.
If all my ducks line up I figure I'll just be able to fit those 275's up
front with 2.5 to 3 degrees camber and a two-inch drop, missing the
bodywork by a fly's foreskin. I may have to roll the front fender a bit.
It's a lot of work. Yeah, I know, "should have bought a vette". But hey, I'll
never be the fastest street-legal vette around a road course, but I may well
be the fastest GTO
With 56mm offsets the rears will bolt right up (my street rears are 285mm on
54mm offset CCWs, so all the fender grinding has been done).
For the fronts I'll use a 19mm adapter and will push the coilover 12mm
inboard with an eccentric bushing at the top and by extending and
redrilling the wheel mounting plates at the bottom. Might need to step up
to a 100mm 750lb spring so the coilover adjustment collar clears the tire.
If all my ducks line up I figure I'll just be able to fit those 275's up
front with 2.5 to 3 degrees camber and a two-inch drop, missing the
bodywork by a fly's foreskin. I may have to roll the front fender a bit.
It's a lot of work. Yeah, I know, "should have bought a vette". But hey, I'll
never be the fastest street-legal vette around a road course, but I may well
be the fastest GTO
11-16-2008, 05:27 AM
#15
Le Mans Master
275mm r-comps all round.
With 56mm offsets the rears will bolt right up (my street rears are 285mm on
54mm offset CCWs, so all the fender grinding has been done).
For the fronts I'll use a 19mm adapter and will push the coilover 12mm
inboard with an eccentric bushing at the top and by extending and
redrilling the wheel mounting plates at the bottom. Might need to step up
to a 100mm 750lb spring so the coilover adjustment collar clears the tire.
If all my ducks line up I figure I'll just be able to fit those 275's up
front with 2.5 to 3 degrees camber and a two-inch drop, missing the
bodywork by a fly's foreskin. I may have to roll the front fender a bit.
It's a lot of work. Yeah, I know, "should have bought a vette". But hey, I'll
never be the fastest street-legal vette around a road course, but I may well
be the fastest GTO
With 56mm offsets the rears will bolt right up (my street rears are 285mm on
54mm offset CCWs, so all the fender grinding has been done).
For the fronts I'll use a 19mm adapter and will push the coilover 12mm
inboard with an eccentric bushing at the top and by extending and
redrilling the wheel mounting plates at the bottom. Might need to step up
to a 100mm 750lb spring so the coilover adjustment collar clears the tire.
If all my ducks line up I figure I'll just be able to fit those 275's up
front with 2.5 to 3 degrees camber and a two-inch drop, missing the
bodywork by a fly's foreskin. I may have to roll the front fender a bit.
It's a lot of work. Yeah, I know, "should have bought a vette". But hey, I'll
never be the fastest street-legal vette around a road course, but I may well
be the fastest GTO
you are changing the bolt pattern?
junk it before explosion
11-16-2008, 08:55 AM
#17
Team Owner
I never let em get that bad
Considering the price of NAPA ultrapremium rotors for my C6, it simply ain't worth going that far, especially when you consider what could happen at speed.
11-16-2008, 12:09 PM
#18
Race Director
Got your moneys worth out of that rotor!!! 
11-16-2008, 12:10 PM
#19
Le Mans Master
Thread Starter
Yep by the book. I do have a couple of hundred street miles on them though. Maybe that's where it's coming from since the pads aren't getting up to temp. I don't have any pulsating, it's just the cracks that have me worried.
