6Speeder

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.

racezx9

best part of this thread...lol.

lawdogg149

This is where the weather strip is. I removed mine in 5 mins. Goes back as quick.

BobSWFL

6Speeder is talking about removing the weatherstrip at the base of the windshield:


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.

C7/Z06 Man

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.

BobSWFL

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.

Bill Dearborn

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

BobSWFL

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.

VermontWayne

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.

BobSWFL

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.

RBK

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

ncrowe

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.

Cyclone09Z06

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.

Cyclone09Z06

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.

ncrowe

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

Cyclone09Z06

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.

Cyclone09Z06

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.

RBK

This seems to be the bottom line. Best

LSs1Power

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.

Cyclone09Z06

[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