View Poll Results: If you've Overheated What is Your Stage Aero 1, 2 or 3
Voters: 348. You may not vote on this poll
ZO6 overheating issues ***MEGA Merge***
05-07-2015, 06:38 PM
#2101
I agree that Tadge's comments are sufficiently vague as to not exactly say how hard the car can be driven and not overheat. It sure seems like some of the quicker track drivers are having very high fluid temperatures (I for one never allow one of my race cars over 240 water or 280-90-ish oil) that really shock me. 260 water? Yikes. 300+ oil? From what I have read that really means an oil change every few hours of operation.
I am a huge GM and Corvette fan; I've owned several including the C6Z and my DD is a CTS-V Wagon. But I decided to pay more for "less," by buying a GT3. Why? Well partially I just wanted to try a P car as I've never had a street Porsche, but I also liked the lighter weight and lower power, as I figure it's easier to cool 475 hp and Porsche somehow manages to punch way above its weight in terms of lap times for the power level. I would have been much more impressed if the C7 Z06 went down in weight with a modest increase in power (imagine say 3000 lb and 525-50 hp) with a big emphasis on cooling and brakes.
Problem is, I really think the Corvette demographic would rather have the power than serious track ability, and of course lower price. The car is fantastic looking, can lay down a serious hero lap, and drag race in the 10s. But hard, race-pace track driving is very expensive to design and build for and a complete waste if the driver never really uses the car that hard and I honestly don't think most Corvette owners track their cars with great pace (present company excluded). I can't blame Chevy for building to this market, but that's exactly what I think happened.
I am a huge GM and Corvette fan; I've owned several including the C6Z and my DD is a CTS-V Wagon. But I decided to pay more for "less," by buying a GT3. Why? Well partially I just wanted to try a P car as I've never had a street Porsche, but I also liked the lighter weight and lower power, as I figure it's easier to cool 475 hp and Porsche somehow manages to punch way above its weight in terms of lap times for the power level. I would have been much more impressed if the C7 Z06 went down in weight with a modest increase in power (imagine say 3000 lb and 525-50 hp) with a big emphasis on cooling and brakes.
Problem is, I really think the Corvette demographic would rather have the power than serious track ability, and of course lower price. The car is fantastic looking, can lay down a serious hero lap, and drag race in the 10s. But hard, race-pace track driving is very expensive to design and build for and a complete waste if the driver never really uses the car that hard and I honestly don't think most Corvette owners track their cars with great pace (present company excluded). I can't blame Chevy for building to this market, but that's exactly what I think happened.
The C7 Z06 is still awesome, it's just compromised. If it's being marketed as a car (Z07) that is extremely capable for the track then it should be able to run a full 20 minute session without sky high oil and water temperature.
How do you like the GT3 so far? I've driven one on the street and it was an awesome experience. It's such a great car and I can only imagine how good it is on the track.
05-07-2015, 06:45 PM
#2102
Melting Slicks
I agree that Tadge's comments are sufficiently vague as to not exactly say how hard the car can be driven and not overheat. It sure seems like some of the quicker track drivers are having very high fluid temperatures (I for one never allow one of my race cars over 240 water or 280-90-ish oil) that really shock me. 260 water? Yikes. 300+ oil? From what I have read that really means an oil change every few hours of operation.
I am a huge GM and Corvette fan; I've owned several including the C6Z and my DD is a CTS-V Wagon. But I decided to pay more for "less," by buying a GT3. Why? Well partially I just wanted to try a P car as I've never had a street Porsche, but I also liked the lighter weight and lower power, as I figure it's easier to cool 475 hp and Porsche somehow manages to punch way above its weight in terms of lap times for the power level. I would have been much more impressed if the C7 Z06 went down in weight with a modest increase in power (imagine say 3000 lb and 525-50 hp) with a big emphasis on cooling and brakes.
Problem is, I really think the Corvette demographic would rather have the power than serious track ability, and of course lower price. The car is fantastic looking, can lay down a serious hero lap, and drag race in the 10s. But hard, race-pace track driving is very expensive to design and build for and a complete waste if the driver never really uses the car that hard and I honestly don't think most Corvette owners track their cars with great pace (present company excluded). I can't blame Chevy for building to this market, but that's exactly what I think happened.
I am a huge GM and Corvette fan; I've owned several including the C6Z and my DD is a CTS-V Wagon. But I decided to pay more for "less," by buying a GT3. Why? Well partially I just wanted to try a P car as I've never had a street Porsche, but I also liked the lighter weight and lower power, as I figure it's easier to cool 475 hp and Porsche somehow manages to punch way above its weight in terms of lap times for the power level. I would have been much more impressed if the C7 Z06 went down in weight with a modest increase in power (imagine say 3000 lb and 525-50 hp) with a big emphasis on cooling and brakes.
Problem is, I really think the Corvette demographic would rather have the power than serious track ability, and of course lower price. The car is fantastic looking, can lay down a serious hero lap, and drag race in the 10s. But hard, race-pace track driving is very expensive to design and build for and a complete waste if the driver never really uses the car that hard and I honestly don't think most Corvette owners track their cars with great pace (present company excluded). I can't blame Chevy for building to this market, but that's exactly what I think happened.
Regardless, the Z07 package should have been sold as a street vehicle that was 'HPDE/road course' ready, and should have had the requisite modifications for the advanced HPDE driver to enjoy the car for the normal run session in hot weather. I am convinced that owners like me would have paid an additional $5K for an additional EOC +/- a more efficient radiator. Oh, and a cooling solution for the PS unit.
Bish
05-07-2015, 06:51 PM
#2103
V10LEE
05-08-2015, 11:49 AM
#2104
Was that the highest all day? Did the oil temp continue to climb?What was the water temp? How many laps and how hard were you pushing it?
I usually don't want to see any more than 240 water/270 oil, but synthetics can handle a bit more. Best
05-08-2015, 11:49 AM
#2105
I usually don't want to see any more than 240 water/270 oil, but synthetics can handle a bit more. Best[/QUOTE]
05-08-2015, 02:23 PM
#2106
Safety Car
Umm, it was a morning drive on a canyon road. I didn't track water temps at that time. I've only seen 280*+ oil temps on a track, even in 40* weather.
05-08-2015, 04:12 PM
#2107
At the IMSA race last weekend at Laguna Seca a question regarding C7 Z06 temperatures was posed to Tadge after his presentation to the Corvette Corral.
The question was "what are the maximum safe coolant and oil temperatures for the C7 Z06". Not surprisingly, his reply was that he would not quote specific temperatures but rather only that the car has self-protection measures for when it gets too hot. He also mentioned that their own internal testing did not seem to show a widespread overheating problem other than the few instances already mentioned in the major publications (Motor Trend for one).
Another person asked whether or not GM would make a hardcore Z06 (a la Porsche GT3 RS). His answer was that such a thing is on their list, but per company policy on future product he cannot comment on how high or low on the list it is.
The question was "what are the maximum safe coolant and oil temperatures for the C7 Z06". Not surprisingly, his reply was that he would not quote specific temperatures but rather only that the car has self-protection measures for when it gets too hot. He also mentioned that their own internal testing did not seem to show a widespread overheating problem other than the few instances already mentioned in the major publications (Motor Trend for one).
Another person asked whether or not GM would make a hardcore Z06 (a la Porsche GT3 RS). His answer was that such a thing is on their list, but per company policy on future product he cannot comment on how high or low on the list it is.
05-08-2015, 04:31 PM
#2108
Le Mans Master
1. You're referring to an old *** car, with an old *** stock rad
2. You're not road racing it/tracking it for any sustainable amount of time
3. The airflow that goes in and through that old car is apples to oranges to the C7
4. Your big block didnt' have an additional heat pump strapped to the top that needed cooled as well
The job the Dewitt had to do for you was easily solved. I'm not saying a larger, aluminum rad isn't effective, but I'm saying that the night and day difference it made for you was because the job it had to do was so much less demanding.
05-08-2015, 04:36 PM
#2109
Le Mans Master
I can almost guarantee that the number of 86 degrees Tadge repeats was the target number used to calculate numerical data. Data that you plug in to design the system as a whole, like when calculating outlet temps by the supercharger when you have "x" ambient temp, etc. Any time you calculate the size of a compressor, you always have to factor in engine bay temp and ambient temp. During the course of development, I am willing to bet the number was 86 degrees.
What this does NOT mean though, and it's how people are interpreting it, was that Tadge and team pounded on this car in 86 degree weather and all was good. That's NOT what happened...period. This is more of Tadge double speak. He says with FACT 86 degrees was the test data target...that's true...but only when calculating outlet temps, intercooling capacity, etc...not real world 86 degrees at the track sustained round and round...nope....
What this does NOT mean though, and it's how people are interpreting it, was that Tadge and team pounded on this car in 86 degree weather and all was good. That's NOT what happened...period. This is more of Tadge double speak. He says with FACT 86 degrees was the test data target...that's true...but only when calculating outlet temps, intercooling capacity, etc...not real world 86 degrees at the track sustained round and round...nope....
05-10-2015, 01:09 PM
#2110
Overheating at the track; Paddle shifting A8 seems to help
We're at Thunderhill this weekend. Highs yesterday in low 80s; expected mid 80s today.
While driving in "D," we overheated in the afternoon (probably 80* in paddock, hotter on track). First time was after four laps, got "high oil temps, idle engine" warning. Curiously, the A8 in "D" mode still holds the revs crazy high EVEN THOUGH THE CAR KNOWS IT IS OVERHEATING. Seems like an opportunity for improvement. The next session, got the trifecta of power steering failure, followed by "high oil temp" warnings, plus limp mode.
Looking at the PDR data, highest oil temps were ~300-305* and highest water 264*.
I ran the last session shifting manually and temps (oil and water) were about 20* cooler. Still running WOT and redline shifting on the straights, but running 1 or 2 gears higher than "D" through the turns.
Another observation: oil temps rise very quickly, and then water temps rise. Even though car (for us) reports high oil temps first, you can see from data that the warning pops up when the WATER gets above ~250*.
While driving in "D," we overheated in the afternoon (probably 80* in paddock, hotter on track). First time was after four laps, got "high oil temps, idle engine" warning. Curiously, the A8 in "D" mode still holds the revs crazy high EVEN THOUGH THE CAR KNOWS IT IS OVERHEATING. Seems like an opportunity for improvement. The next session, got the trifecta of power steering failure, followed by "high oil temp" warnings, plus limp mode.
Looking at the PDR data, highest oil temps were ~300-305* and highest water 264*.
I ran the last session shifting manually and temps (oil and water) were about 20* cooler. Still running WOT and redline shifting on the straights, but running 1 or 2 gears higher than "D" through the turns.
Another observation: oil temps rise very quickly, and then water temps rise. Even though car (for us) reports high oil temps first, you can see from data that the warning pops up when the WATER gets above ~250*.
Last edited by ChrisN123; 05-11-2015 at 11:39 AM.
05-10-2015, 01:16 PM
#2111
Has anybody out there tried a lower thermostat and reprogram the fans?
I had a C5 with a Maggi SC ran a 160 stat, reprogramed the fans and used an additive from Royal Purple with my coolant. The car never ran above 195 either drag racing or city driving. Just a thought.
Awaitng arrivial of my Z in June was going to do the same procedure. Will post results.
v/r
THEYAV
05-10-2015, 01:20 PM
#2112
Racer
We're at Thunderhill this weekend. Highs yesterday in low 80s; expected mid 80s today.
While driving in "D," we overheated in the afternoon (probably 80* in paddock, hotter on track). First time was after four laps, got "high oil temps, idle engine" warning. Curiously, the A8 in "D" mode still holds the revs crazy high EVEN THOUGH THEY CAR KNOWS IT IS OVERHEATING. Seems like an opportunity for improvement. The next session, got the trifecta of power steering failure, followed by "high oil temp" warnings, plus limp mode.
Looking at the PDR data, highest oil temps were ~300-305* and highest water 264*.
I ran the last session shifting manually and temps (oil and water) were about 20* cooler. Still running WOT and redline shifting on the straights, but running 1 or 2 gears higher than "D" through the turns.
Another observation: oil temps rise very quickly, and then water temps rise. Even though car (for us) reports high oil temps first, you can see from data that the warning pops up when the WATER gets above 250*.
While driving in "D," we overheated in the afternoon (probably 80* in paddock, hotter on track). First time was after four laps, got "high oil temps, idle engine" warning. Curiously, the A8 in "D" mode still holds the revs crazy high EVEN THOUGH THEY CAR KNOWS IT IS OVERHEATING. Seems like an opportunity for improvement. The next session, got the trifecta of power steering failure, followed by "high oil temp" warnings, plus limp mode.
Looking at the PDR data, highest oil temps were ~300-305* and highest water 264*.
I ran the last session shifting manually and temps (oil and water) were about 20* cooler. Still running WOT and redline shifting on the straights, but running 1 or 2 gears higher than "D" through the turns.
Another observation: oil temps rise very quickly, and then water temps rise. Even though car (for us) reports high oil temps first, you can see from data that the warning pops up when the WATER gets above 250*.
Have you tried any of the other recommendations like removing the weather stripping near the top/back of the hood, adding "40 below" or "water wetter", etc.?
Save the wave!
05-10-2015, 01:32 PM
#2113
Race Director
I don't have my car yet, so I can't suggest the best spot for it, but behind the auto trans cooler may be a possible spot, if you can get airflow to it. This may require some tweaking to the front bottom panel.
I would also suggest a thermostatic controlled valve to direct oil into that cooler only after oil gets to over 200F, would be a nice addition if it is possible to include one.
Doug
05-10-2015, 01:50 PM
#2114
Safety Car
Ouch, that sounds like my experience at Thunderhill. I have the manual, but that doesn't seem to make it much more effective at cooling.
What are we going to do about the powersteering? I thought removing the under tray may bring more air in but it is too short to cover the powersteering unit anyway. It is vented already below.
Unlike the engine, I couldn't do cooling laps to cool the power steering unit. It just got worse and worse and felt that it was unsafe to drive it around at all.
What are we going to do about the powersteering? I thought removing the under tray may bring more air in but it is too short to cover the powersteering unit anyway. It is vented already below.
Unlike the engine, I couldn't do cooling laps to cool the power steering unit. It just got worse and worse and felt that it was unsafe to drive it around at all.
05-10-2015, 02:19 PM
#2115
Racer
Ford added an air scoop to cool their Mustang GT/Boss transmission. Here's a link of an example:
http://www.americanmuscle.com/frpp-t...op-1113gt.html
Perhaps we could do something similar with the front splitter/under-tray? I'm thinking a supporting vendor might be able to build an aftermarket splitter/tray with a built in scoop (preferably as a single reinforced piece of molded product) that takes up as much space as possible between the two front wheels. This would incorporate a very wide downward facing opening/wing integrated into the under-tray. I would imagine it would slightly increase drag, but it might also increase downforce at speed while increasing pressure into the engine bay.
If we could perhaps direct that pressure through the auto-trans cooler, towards the power steering unit, and/or through an external oil cooler, all the better. That being said, it might create too much turbulence and that might, as a result, generate lift.
Thoughts?
http://www.americanmuscle.com/frpp-t...op-1113gt.html
Perhaps we could do something similar with the front splitter/under-tray? I'm thinking a supporting vendor might be able to build an aftermarket splitter/tray with a built in scoop (preferably as a single reinforced piece of molded product) that takes up as much space as possible between the two front wheels. This would incorporate a very wide downward facing opening/wing integrated into the under-tray. I would imagine it would slightly increase drag, but it might also increase downforce at speed while increasing pressure into the engine bay.
If we could perhaps direct that pressure through the auto-trans cooler, towards the power steering unit, and/or through an external oil cooler, all the better. That being said, it might create too much turbulence and that might, as a result, generate lift.
Thoughts?
Last edited by A-Pex; 05-10-2015 at 02:32 PM.
05-10-2015, 02:35 PM
#2117
Safety Car
Ford added an air scoop to cool their Mustang GT/Boss transmission. Here's a link of an example:
http://www.americanmuscle.com/frpp-t...op-1113gt.html
Perhaps we could do something similar with the front splitter/under-tray? I'm thinking a supporting vendor might be able to build an aftermarket splitter/tray with a built in scoop (preferably as a single reinforced piece of molded product) that takes up as much space as possible between the two front wheels. This would incorporate a very wide downward facing opening/wing integrated into the under-tray. I would imagine it would slightly increase drag, but it might also increase downforce at speed while increasing pressure into the engine bay.
If we could perhaps direct that pressure through the auto-trans cooler, towards the power steering unit, and/or through an external oil cooler, all the better. That being said, it might create too much turbulence and that might, as a result, generate lift.
Thoughts?
http://www.americanmuscle.com/frpp-t...op-1113gt.html
Perhaps we could do something similar with the front splitter/under-tray? I'm thinking a supporting vendor might be able to build an aftermarket splitter/tray with a built in scoop (preferably as a single reinforced piece of molded product) that takes up as much space as possible between the two front wheels. This would incorporate a very wide downward facing opening/wing integrated into the under-tray. I would imagine it would slightly increase drag, but it might also increase downforce at speed while increasing pressure into the engine bay.
If we could perhaps direct that pressure through the auto-trans cooler, towards the power steering unit, and/or through an external oil cooler, all the better. That being said, it might create too much turbulence and that might, as a result, generate lift.
Thoughts?
The other downside is that in order to make it more effective it has to hang lower. That reduces the underbody clearance and upon spinning off at the track you can break it along with whatever else you mounted it to.
05-10-2015, 02:42 PM
#2118
Melting Slicks
Gents,
Has anybody out there tried a lower thermostat and reprogram the fans?
I had a C5 with a Maggi SC ran a 160 stat, reprogramed the fans and used an additive from Royal Purple with my coolant. The car never ran above 195 either drag racing or city driving. Just a thought.
Awaitng arrivial of my Z in June was going to do the same procedure. Will post results.
v/r
THEYAV
Has anybody out there tried a lower thermostat and reprogram the fans?
I had a C5 with a Maggi SC ran a 160 stat, reprogramed the fans and used an additive from Royal Purple with my coolant. The car never ran above 195 either drag racing or city driving. Just a thought.
Awaitng arrivial of my Z in June was going to do the same procedure. Will post results.
v/r
THEYAV
