View Poll Results: If you've Overheated What is Your Stage Aero 1, 2 or 3
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ZO6 overheating issues ***MEGA Merge***
#1981
Race Director
Member Since: Nov 2000
Location: CA
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2017 C5 of the Year Finalist
St. Jude Donor '08
Your C6Z06 has been bulletproof. You know why? It's because it is a naturally aspirated car. Track cars are not meant to be forced induction. Period. This is also why all GT3s have been naturally aspirated. It's extremely difficult to cool down a 650 hp super charged engine. People who expect GM to come out with a trick and suddenly fix this is hardly mistaken.
While I only run my Supercharged C5 in corvette club events, and leave plenty on the table so as to drive it home in one piece, my oil and coolant temps can stay well within my comfort zone for a 20 minute track session at 90 plus degrees...
Yes, LOTS of coolers and supporting Mods:
Here is a little video I put together last year. The ZR1 is still learning the track, and has now gone MUCH faster for the record.
#1982
89X
Track Days
After one track weekend, no problems with my Z06/7. I have two more events coming up including Road Atlanta early May. I am a little nervous about Atlanta as so far I am very happy with my purchase. I do not feel that I should have to worry about oil and coolant temps after a few hard laps, but we will see.
#1983
Melting Slicks
After one track weekend, no problems with my Z06/7. I have two more events coming up including Road Atlanta early May. I am a little nervous about Atlanta as so far I am very happy with my purchase. I do not feel that I should have to worry about oil and coolant temps after a few hard laps, but we will see.
What run group are you in?
Ambient temp?
#1984
89X
#1985
Admin Gods: It might be helpful to have a sticky where people can post "just the facts" about heat results (ideally PDR lap-by-lap screen) with relevant details (ambient temps, track config, lap times, skill/speed of driver, M7/A8, if A8 then auto or manual).
#1986
89X
Fitz, did you run in Automatic, or manual/paddle shift?
Admin Gods: It might be helpful to have a sticky where people can post "just the facts" about heat results (ideally PDR lap-by-lap screen) with relevant details (ambient temps, track config, lap times, skill/speed of driver, M7/A8, if A8 then auto or manual).
Admin Gods: It might be helpful to have a sticky where people can post "just the facts" about heat results (ideally PDR lap-by-lap screen) with relevant details (ambient temps, track config, lap times, skill/speed of driver, M7/A8, if A8 then auto or manual).
#1987
Alcoholics Unanimous
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St. Jude Donor '15-'16
For what it is worth I ran my M7 this weekend for a full day at Roebling Rd in GA with Just Track It. Novice group, 6 25min sessions averaging about an hour in between, low 60s, zero heat issues. I'll do a thread on it later with pics and vids but I just wanted to mention the temp topic here.
#1989
Former Vendor
Member Since: Aug 2005
Location: Lewisville TX
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St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13
For those interested.
Start of the run
End of the run
It would not let me display the entire run on one screen, so you can see at the start the car was only 120 F water temp when he was rolling up to the grid. I was logging a lot of things so there are some skips in the data.
Start of the run
End of the run
It would not let me display the entire run on one screen, so you can see at the start the car was only 120 F water temp when he was rolling up to the grid. I was logging a lot of things so there are some skips in the data.
#1990
It will be interesting to see what the usable performance available actually is on a 90 degree plus track day.
I am thinking in terms of cars.
Will a GT4 actually be quicker because it can maintain 100 percent?
What about a Z51 C7? Will they ever have a Grand Sport? Would that be basically a Z06 with a Stingray motor? That might be one hell of a car.
I'd still want the ability to dial it up to "11" and run a few screaming laps...even if to requires a cool down.
The A8 Z06 has afterburners. You can't run them all day long. So what?
You don't want that extra power? Don't use it, then.
I am thinking in terms of cars.
Will a GT4 actually be quicker because it can maintain 100 percent?
What about a Z51 C7? Will they ever have a Grand Sport? Would that be basically a Z06 with a Stingray motor? That might be one hell of a car.
I'd still want the ability to dial it up to "11" and run a few screaming laps...even if to requires a cool down.
The A8 Z06 has afterburners. You can't run them all day long. So what?
You don't want that extra power? Don't use it, then.
#1991
Z06 8-speed overheating?
I know the C7 Z51 8 speed transmission tends to overheat with track use... but what about the Z06 automatic?
I know they added a second transmission cooler, is that enough? Or still heat soak issues with the Z06?
Thanks.
I know they added a second transmission cooler, is that enough? Or still heat soak issues with the Z06?
Thanks.
#1993
Burning Brakes
Member Since: Sep 2007
Location: Cedar Rapids Iowa
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Heat soak is typically associated with hot intakes, supercharger bodies and the like when radiation or conduction causes excessive heat to build up in places that negatively affect performance.
An automatic transmission just gets plain hot. It depends a lot on how you're shifting when driving, outside temp, and even the speed of the track. A low speed track with a lot of shifting on a hot day, and I'd guess the auto will run hot. How hot is tough to say until it happens.
I had an A6 in my 2008 Z51, and if I drove it hard keeping the RPM high there was no way it could keep temps down over time. Just by changing the downshift points it would run much cooler. I'd guess the Z06 A8 will do fine, 99% of the time.
An automatic transmission just gets plain hot. It depends a lot on how you're shifting when driving, outside temp, and even the speed of the track. A low speed track with a lot of shifting on a hot day, and I'd guess the auto will run hot. How hot is tough to say until it happens.
I had an A6 in my 2008 Z51, and if I drove it hard keeping the RPM high there was no way it could keep temps down over time. Just by changing the downshift points it would run much cooler. I'd guess the Z06 A8 will do fine, 99% of the time.
#1995
#1996
From what i have read you will probably worry more about the engine heat soaking before the transmission. Specially if they added a second trans cooler.
#1997
Z06 overheating-Fix 1 underhood duct/shroud
Edit: This mod is intended to INCREASE the volume of air venting out through the existing vents in the hood. This mod is for the track. You don't need it on the street.
This free C7 Z06 mod might increase total cooling capacity by up to 20%. I can't get to the track for a few months to try this. Hopefully someone can do it before then.
(Please read my notes and disclaimer after the pictures.)
Totally remove this black plastic duct that channels air from the top of the radiator to the underhood vent shroud:
Totally remove this black plastic shroud that is attached under the hood vent:
Note 1: I'm not sure if the radiator duct bolts support anything besides the duct. If they do, then re-install the bolts (without the duct) to hold everything in place.
Note 2 The hood liner might flap around if you leave it loose after removing the plastic shroud. Try re-installing just the shroud screws with fender washers or some other type of washer. Or remove the hood liner.
Disclaimer: This mod cannot be approved by GM, since it may expose the user to a few new (possibly) dangerous situations. For example, if a radiator hose fails, coolant now has a quick path through the unshielded hood vents and onto the windshield.
Also, in winter climates water could drip in through the exposed hood vents and freeze on the front of the engine.
Final Thoughts: I suggest someone try this simple mod after confirming they can get their car to overheat on a track day. Then remove the duct and shroud and see if the overheating is diminished.
The results of this experiment will determine the next area of concern. For example, is overheating caused by insufficient underhood air flow/extraction, or an inadequate radiator?
This free C7 Z06 mod might increase total cooling capacity by up to 20%. I can't get to the track for a few months to try this. Hopefully someone can do it before then.
(Please read my notes and disclaimer after the pictures.)
Totally remove this black plastic duct that channels air from the top of the radiator to the underhood vent shroud:
Totally remove this black plastic shroud that is attached under the hood vent:
Note 1: I'm not sure if the radiator duct bolts support anything besides the duct. If they do, then re-install the bolts (without the duct) to hold everything in place.
Note 2 The hood liner might flap around if you leave it loose after removing the plastic shroud. Try re-installing just the shroud screws with fender washers or some other type of washer. Or remove the hood liner.
Disclaimer: This mod cannot be approved by GM, since it may expose the user to a few new (possibly) dangerous situations. For example, if a radiator hose fails, coolant now has a quick path through the unshielded hood vents and onto the windshield.
Also, in winter climates water could drip in through the exposed hood vents and freeze on the front of the engine.
Final Thoughts: I suggest someone try this simple mod after confirming they can get their car to overheat on a track day. Then remove the duct and shroud and see if the overheating is diminished.
The results of this experiment will determine the next area of concern. For example, is overheating caused by insufficient underhood air flow/extraction, or an inadequate radiator?
Last edited by BobSWFL; 04-29-2015 at 08:04 PM.
#1998
Two questions
This free C7 Z06 mod might increase total cooling capacity by up to 20%. I can't get to the track for a few months to try this. Hopefully someone can do it before then.
(Please read my notes and disclaimer after the pictures.)
Totally remove this black plastic duct that channels air from the top of the radiator to the underhood vent shroud:
Attachment 47881810
Totally remove this black plastic shroud that is attached under the hood vent:
Attachment 47881811
Note 1: I'm not sure if the radiator duct bolts support anything besides the duct. If they do, then re-install the bolts (without the duct) to hold everything in place.
Note 2 The hood liner might flap around if you leave it loose after removing the plastic shroud. Try re-installing just the shroud screws with fender washers or some other type of washer. Or remove the hood liner.
Disclaimer: This mod cannot be approved by GM, since it may expose the user to a few new (possibly) dangerous situations. For example, if a radiator hose fails, coolant now has a quick path through the unshielded hood vents and onto the windshield.
Also, in winter climates water could drip in through the exposed hood vents and freeze on the front of the engine.
Final Thoughts: I suggest someone try this simple mod after confirming they can get their car to overheat on a track day. Then remove the duct and shroud and see if the overheating is diminished.
The results of this experiment will determine the next area of concern. For example, is overheating caused by insufficient underhood air flow/extraction, or an inadequate radiator?
(Please read my notes and disclaimer after the pictures.)
Totally remove this black plastic duct that channels air from the top of the radiator to the underhood vent shroud:
Attachment 47881810
Totally remove this black plastic shroud that is attached under the hood vent:
Attachment 47881811
Note 1: I'm not sure if the radiator duct bolts support anything besides the duct. If they do, then re-install the bolts (without the duct) to hold everything in place.
Note 2 The hood liner might flap around if you leave it loose after removing the plastic shroud. Try re-installing just the shroud screws with fender washers or some other type of washer. Or remove the hood liner.
Disclaimer: This mod cannot be approved by GM, since it may expose the user to a few new (possibly) dangerous situations. For example, if a radiator hose fails, coolant now has a quick path through the unshielded hood vents and onto the windshield.
Also, in winter climates water could drip in through the exposed hood vents and freeze on the front of the engine.
Final Thoughts: I suggest someone try this simple mod after confirming they can get their car to overheat on a track day. Then remove the duct and shroud and see if the overheating is diminished.
The results of this experiment will determine the next area of concern. For example, is overheating caused by insufficient underhood air flow/extraction, or an inadequate radiator?
2. Has anyone tried expanding the size of or adding a second hood vent to increase evacuation of under hood air/heat?
#1999
I'm sure GM worked hard on the correct way to move air in the engine compartment. Yes they have restrictions, as noted above w water intrusion, etc. I agree w experimenting, but I remember once dealing w a friends firebird that overheated only when at highway speeds. Ended up being the small air deflector mounted way up under the radiator that was removed or knocked off. It created the low pressure needed to draw the air out of the engine compartment. I would be cautious, but give it a try, while waiting that temp gauge closely.