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ZO6 overheating issues ***MEGA Merge***

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ZO6 overheating issues ***MEGA Merge***

 
Old 05-06-2015, 08:35 AM
  #2041  
6Speeder
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Originally Posted by C7/Z06 Man View Post
No, the weatherstripping is in front or on the front of the plastic trim piece the wiper arms go through. It's a soft hollow strip of black rubber that goes from one side to the other side on the top of the fire wall. The end of the weatherstripping has a hollow black rubber block covering it if I remember correctly that you can just pick up some with your fingers.

TRACK DAY STUFF:
I like the suggestion above (dmaxx3500) of wedging the rear of the hood open some for additional underhood air/heat removal. No removal of parts and very quick to return to stock; also the removing of the firewall weather stripping will do the same but no where as large of a rear opening as wedging the rear of the hood open.
Has anybody tested to see if this actually moves air OUT of the engine bay on the C7? I tested this on the C5, the C6, AND on the CTS-V and on ALL of them it moves air INTO the engine bay at freeway speeds and above. I'm betting that the base of the windshield is a high pressure area and will push air in at speed, not evacuate air out.

Try it yourself: Tape some strings to the edge of the hood, see if they are pushed out or are pulled into the opening at speed. You will be unpleasantly surprised.
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Old 05-06-2015, 08:44 AM
  #2042  
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Originally Posted by soulsea View Post
Stage 4 aero with cooling pack:

best part of this thread...lol.
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Old 05-06-2015, 09:49 AM
  #2043  
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Originally Posted by soulsea View Post
How do you remove the weatherstripping? This is the plastic trim piece the wiper arms go through right? Thanks.


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This is where the weather strip is. I removed mine in 5 mins. Goes back as quick.
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Old 05-06-2015, 10:33 AM
  #2044  
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6Speeder is talking about removing the weatherstrip at the base of the windshield:

Originally Posted by 6Speeder View Post
Has anybody tested to see if this actually moves air OUT of the engine bay on the C7? I tested this on the C5, the C6, AND on the CTS-V and on ALL of them it moves air INTO the engine bay at freeway speeds and above. I'm betting that the base of the windshield is a high pressure area and will push air in at speed, not evacuate air out.

Try it yourself: Tape some strings to the edge of the hood, see if they are pushed out or are pulled into the opening at speed. You will be unpleasantly surprised.

I've always used the base of the windshield as the best high pressure location for engine intake air. Removing the weatherstrip probably forces more air into the engine compartment and out the bottom of the car. Can't hurt.

We are looking for a way to vent more air. So far, it looks like my duct removal mod makes some progress there.
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Old 05-06-2015, 10:35 AM
  #2045  
C7/Z06 Man
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Default Wedging the hood/removing the weatherstrip.

Originally Posted by 6Speeder View Post
Has anybody tested to see if this actually moves air OUT of the engine bay on the C7? I tested this on the C5, the C6, AND on the CTS-V and on ALL of them it moves air INTO the engine bay at freeway speeds and above. I'm betting that the base of the windshield is a high pressure area and will push air in at speed, not evacuate air out.

Try it yourself: Tape some strings to the edge of the hood, see if they are pushed out or are pulled into the opening at speed. You will be unpleasantly surprised.
Still maybe a good thing, the outside air is cooler than what's in the engine bay. If I had a overheating problem on the track I would at lease give it a try.

Last edited by C7/Z06 Man; 05-06-2015 at 10:44 AM.
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Old 05-06-2015, 10:46 AM
  #2046  
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Re. all this hand-wringing about "upsetting the delicate balance from the blessed GM engineers." Let it go! The engineers are hobbled by needs for mpg, CAFE, and sound abatement. We are not. We are racing the car on a track.

This is an incredible car, one of the best ever made, but it is not a sacred religious artifact. We can experiment, learn, then move on.

Additional hood venting will not make the car take off like an airplane.


Last edited by BobSWFL; 05-06-2015 at 01:53 PM.
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Old 05-06-2015, 02:30 PM
  #2047  
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The front to the middle of the hood is a low pressure area. The base of the windshield is a high pressure area. That is why the mid to late 60s front mounted hood scoops on the GTO didn't work well and why the L88 Corvettes had rear facing hood scoops.

The problem with removing the duct under the hood is you can't be sure it is always venting air that went through the radiator. The duct prevents air that enters the engine compartment from under the car from exiting through the hood thus actually enhances cooling by making sure all the air that goes out through the hood vent went through the radiator.

Automakers don't spend money on parts that aren't required. If the duct wasn't needed to enhance cooling they wouldn't have spent the time and money required to engineer it in the first place. To prevent outside water/dirt from getting on the engine they could have just designed a cheap plastic shield with a Vette Logo on it.

Bill

Last edited by Bill Dearborn; 05-06-2015 at 02:33 PM.
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Old 05-06-2015, 03:47 PM
  #2048  
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Originally Posted by ncrowe View Post
I tried this today

Removed the duct and the hood shroud as well as the weatherstripping on the firewall. Lowered my temps 10 degrees - with ac on - 210 max temp. With AC off the temp was fluctuating between 195 and 205, would stay mostly around the 200 mark (15 - 20 degree drop).

I noticed a few really good things - first: when the fan comes on a massive amount of air comes through the hood that was previously trapped in the engine bay. Second: the air intake was cooler because the air being pushed by the fan was getting out of the engine bay.
I noticed no difference in noise, rattles, or anything like that when driving

It too a total of 5 minutes to remove the parts, and would take about 10 minutes to put back on. For the drop in temps I would say this is a good mod.

I'm going to be playing around with a few things with the car - I believe that there are a few basic and easy things that can be done to this car to keep it really cool. I have the spacers and the tank from Formatto coming and a 170 thermostat as well. E85 will be added, and maybe even some meth - this should keep this beast super cool and consistent.
You did a good test, real results.

Ncrowe thank you so much. This is the start of the info we are looking for.

More people say they will try it. The hot summer will give plenty of opportunity.

So far, we can conclude the stock Z06 configuration will benefit from more air venting from the engine compartment.
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Old 05-06-2015, 04:05 PM
  #2049  
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GUYS: The wrong people , though well intended, are trying to solve this overheating design flaw.

Earth to GM, Come in GM. Please solve the design defect you created. And tell us quickly that you recognize the problem and are committed to finding an appropriate solution so we can all feel good about our actual or planned C7 ZO6 purchases.



Originally Posted by SBC_and_a_stick View Post
Not to sound like a jerk, but the only way I see this working is if there is an inherent tradeoff between downforce and cooling. If removing the duct improves both, GM would have done it. It makes no sense to make additional parts to achieve all around less output. They can sell Corvettes with or without a heat shroud. It's all under the hood anyway. It has no marketing purpose.
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Old 05-06-2015, 04:10 PM
  #2050  
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Originally Posted by Bill Dearborn View Post
...
The problem with removing the duct under the hood is you can't be sure it is always venting air that went through the radiator. The duct prevents air that enters the engine compartment from under the car from exiting through the hood thus actually enhances cooling by making sure all the air that goes out through the hood vent went through the radiator.

Automakers don't spend money on parts that aren't required. ...
Bill
Ah, now I understand. Good point - we might be venting air from under the car up through the hood. I didn't think of that.

The ideal solution would be a full-size duct for the entire radiator, plus a much bigger hood vent area to serve that duct. But there are too many obstructions between the engine and the radiator. I just can't justify the existing restrictive duct/shroud which serve such a minor percent of the radiator. The engineers must have been seeking some goal other than maximum cooling.

Regardless, it turns out the duct/shroud removal provides a measurable drop in engine temperatures. Ncrowe found this success in his own recent track test.

These are interesting arguments, but the track test is a deciding factor - it might not even make sense, as long as it works! Looking forward to more results and more theories.
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Old 05-06-2015, 11:04 PM
  #2051  
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Default Overheating - one more time

I have now read "countless" threads with opinion and hypothesis.

Respectfully, no opinion, hypothesis, complaint .

HAS ANYONE SOLVED THE HEAT PROBLEM

If so please share it with us and the data to support your claim.

This may be a one post thread, and I really don't mind.

Best
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Old 05-06-2015, 11:05 PM
  #2052  
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Originally Posted by Bill Dearborn View Post
The front to the middle of the hood is a low pressure area. The base of the windshield is a high pressure area. That is why the mid to late 60s front mounted hood scoops on the GTO didn't work well and why the L88 Corvettes had rear facing hood scoops.

The problem with removing the duct under the hood is you can't be sure it is always venting air that went through the radiator. The duct prevents air that enters the engine compartment from under the car from exiting through the hood thus actually enhances cooling by making sure all the air that goes out through the hood vent went through the radiator.

Automakers don't spend money on parts that aren't required. If the duct wasn't needed to enhance cooling they wouldn't have spent the time and money required to engineer it in the first place. To prevent outside water/dirt from getting on the engine they could have just designed a cheap plastic shield with a Vette Logo on it.

Bill
Try removing the parts your self and see what happens when the fan goes on - when the fan turns on with the part sin place there is absolutely no where for the heat to go but in the engine compartment. with the weatherstrip removal it can get out , but where there is a huge difference is when you remove the ducts that are on the hood - you will feel a massive amount of air moving out of the engine compartment that couldn't before.

Also, take a look at the underside of the car - there is a very small area that air can get into the engine bay from under the car - it is blocked by the steering, intake, radiator hoses, and if the duct work is there the incoming air from under the car has no where to go.

While I would prefer to see GM do something - and the easiest way for them to do something that would work would be to move the air intake to the drivers side - move the lower rad hose down and put a MUCH larger duct moving the radiator air through the hood. Until then I'll take a 15-20 degree drop in temps.

I am going to add an external oil cooler, find a place to mount it, and I will probably see a huge drop in oil temps and more efficiency from the radiator. Oil doesn't cool as quick as coolant, so the oil cooler is more of an oil warmer, once oil temps start to rise without an external cooler, I don't see a good way to drop those temps.
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Old 05-06-2015, 11:05 PM
  #2053  
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Originally Posted by BobSWFL View Post
Ah, now I understand. Good point - we might be venting air from under the car up through the hood. I didn't think of that.

The ideal solution would be a full-size duct for the entire radiator, plus a much bigger hood vent area to serve that duct. But there are too many obstructions between the engine and the radiator. I just can't justify the existing restrictive duct/shroud which serve such a minor percent of the radiator. The engineers must have been seeking some goal other than maximum cooling.

Regardless, it turns out the duct/shroud removal provides a measurable drop in engine temperatures. Ncrowe found this success in his own recent track test.

These are interesting arguments, but the track test is a deciding factor - it might not even make sense, as long as it works! Looking forward to more results and more theories.
Ncrowe did not try this on a track, he did not say he tried on a track, the information he posted was clearly from driving on the street. I did test on the track and it did not work! or at least not enough testing has be done, This is how people misinterpret information.
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Old 05-06-2015, 11:17 PM
  #2054  
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Originally Posted by ncrowe View Post
Try removing the parts your self and see what happens when the fan goes on - when the fan turns on with the part sin place there is absolutely no where for the heat to go but in the engine compartment. with the weatherstrip removal it can get out , but where there is a huge difference is when you remove the ducts that are on the hood - you will feel a massive amount of air moving out of the engine compartment that couldn't before.

Also, take a look at the underside of the car - there is a very small area that air can get into the engine bay from under the car - it is blocked by the steering, intake, radiator hoses, and if the duct work is there the incoming air from under the car has no where to go.

While I would prefer to see GM do something - and the easiest way for them to do something that would work would be to move the air intake to the drivers side - move the lower rad hose down and put a MUCH larger duct moving the radiator air through the hood. Until then I'll take a 15-20 degree drop in temps.

I am going to add an external oil cooler, find a place to mount it, and I will probably see a huge drop in oil temps and more efficiency from the radiator. Oil doesn't cool as quick as coolant, so the oil cooler is more of an oil warmer, once oil temps start to rise without an external cooler, I don't see a good way to drop those temps.
I also wanted this to work however here is my track day results for review, my car is doing other things so testing is not complete.
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Old 05-06-2015, 11:20 PM
  #2055  
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Originally Posted by Cyclone09Z06 View Post
Ncrowe did not try this on a track, he did not say he tried on a track, the information he posted was clearly from driving on the street. I did test on the track and it did not work! or at least not enough testing has be done, This is how people misinterpret information.
You are correct - I did not try this on the track and I can't tell you that it would do a better job cooling. This mod in my opinion works better at low speeds. Thank you for pointing that out to people who aren't understanding that.

I do believe that some de-cluttering of the engine bay and some creative routing of lines would help.

For the track guys a redesign of the hood would be the best answer - get some vents put in the hood
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Old 05-06-2015, 11:22 PM
  #2056  
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Originally Posted by RBK View Post
I have now read "countless" threads with opinion and hypothesis.

Respectfully, no opinion, hypothesis, complaint .

HAS ANYONE SOLVED THE HEAT PROBLEM

If so please share it with us and the data to support your claim.

This may be a one post thread, and I really don't mind.

Best
I also have read them all and have done a lot of testing and I have no solution and have not heard of a solution. I also have not been able to find even small gains on a solution.
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Old 05-06-2015, 11:26 PM
  #2057  
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Originally Posted by ncrowe View Post
You are correct - I did not try this on the track and I can't tell you that it would do a better job cooling. This mod in my opinion works better at low speeds. Thank you for pointing that out to people who aren't understanding that.

I do believe that some de-cluttering of the engine bay and some creative routing of lines would help.

For the track guys a redesign of the hood would be the best answer - get some vents put in the hood
I agree and I am not discounting your analyzes as I think it has legs, I really want us to be able to find a solution and I thank you for testing.
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Old 05-07-2015, 01:19 AM
  #2058  
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This seems to be the bottom line. Best

Originally Posted by Cyclone09Z06 View Post
I also have read them all and have done a lot of testing and I have no solution and have not heard of a solution. I also have not been able to find even small gains on a solution.
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Old 05-07-2015, 01:38 AM
  #2059  
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Im surprised that vendors are not on top of this. I would pay up to 5k to have this fixed properly. I would like to run a car for at least 20mins of hard driving without worrying about overheating!

For the vendors, please over engineer the cooling capacity as most of these cars will have another 100 to 150whp more than factory.
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Old 05-07-2015, 07:31 AM
  #2060  
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[QUOTE=LSs1Power;1589579389]Im surprised that vendors are not on top of this. I would pay up to 5k to have this fixed properly. I would like to run a car for at least 20mins of hard driving without worrying about overheating!

For the vendors, please over engineer the cooling capacity as most of these cars will have another 100 to 150whp more than factory.[/QUOTE

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