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I can't see that it's functional? Seems to me only a small portion of the radiator is flowing though the hood vent and then only at speed. No fan flow is going though the vent. Don't see that it will cool under hood temps because the fan flows directly into the engine compartment. The cowl in front of the radiator that seals against the hood prevents air from coming out of the engine compartment at idle. Also don't even see how the two loops in front of the condenser do anything but block air flow though the radiator. What am I missing?
Yes. All of the vents, ducts, and scoops are functional. Several aerodynamic pics and vids have been posted showing their purpose and functionality.
Edit: Here's one (Stingray) that illustrates how the air flows through the lower front grille and pulls heat from the hood extractors. The GT500 has a similar set-up:
Yes. All of the vents and scoops are functional. Several areo pics and vids have been posted showing their purpose and functionality.
Have a link show the function of the hood vent? I know it flows toward the windshield but for a drag racer having the heat out prior to launching might be best. Seems to me removing the extractor or what ever the connector to the vent is called, would help reduce under hood heat in the staging lanes.
The hood vent is located in a low pressure zone that exists over the hood. The fan doesn't need to blow out through the vent since the fan is turned off once speed exceeds 35 mph as it will impede air flow. Once the car is moving at speed (where you need the cooling) the air flows cleanly through part of the radiator and out of the hood. The vent helps cool the car and reduces front end lift at the same time. In traffic and putt putting around town the fan works well enough even in very hot climates. The car is designed to run in traffic or at idle at very high coolant temps so seeing 220 or 230 coolant temps on the gauge isn't a big deal. If you were driving some other model car there is a probability the gauge wouldn't have temps listed but would show a green section and you would never imagine your coolant temp was actually 235 degrees when it was in the green section.
I understand what you are saying Bill and for a track racer would serve him well. For a drag racer not too sure. I know the Z06 was designed for track but drag racing is all I can do.
Keeping the intercooler and engine cool in the staging lanes is the main objective for getting the best et.
I recently saw a related vid... it was actually released a while ago w/Tadge speaking, but I can't find it now. The cooling illustrated above obviously requires motion.
When staging there is not going to be much cooling. I now see your concerns w/heat soak, but it shouldn't be much of a factor at WOT in a 1/4 mile w/down time; at least not to the extent of hard tracking IMO.
I recently saw a related vid... it was actually released a while ago w/Tadge speaking, but I can't find it now. The cooling illustrated above obviously requires motion.
When staging there is not going to be much cooling. I now see your concerns w/heat soak, but it shouldn't be much of a factor at WOT in a 1/4 mile w/down time; at least not to the extent of hard tracking IMO.
Yes, heat soak. With the hood open heat dissipates better. Same with removing the extractor and opening the hood vent for warm air to escape. And too removing the rubber insulator that seals the back of the hood. And I'm only referring to drag racing and cooling the intercooler prior to launch.
My experience with forward motion air cooling is that it will take farther than the 1/4 mile to do much cooling down to the intercooler. Most of the cooling has to be done before launch.
I understand what you are saying Bill and for a track racer would serve him well. For a drag racer not too sure. I know the Z06 was designed for track but drag racing is all I can do.
Keeping the intercooler and engine cool in the staging lanes is the main objective for getting the best et.
Our hood has a significantly larger louvered area that would help with your situation.
i guess what the OP is asking is... does a radiator cowl/duct exist that sucks ALL the air, or a larger majority of the air, out from the back side of the radiator. Maybe I am wrong, But I have thought this same question myself... why only do the top 1/4 of the radiator when you could do half or even the whole thing.
Granted, one might need a bigger opening in their hood... like LG just displayed... but i dont know if they or anyone has a duct from the radiator UP to that opening, and keep everything sealed up nice.
I've raced many fast cars, none of which had hood vents and none of those ever lifted at 160+ mph. It's a good engineering concept, but I don't really see the need for it to be there. I have done several tests of my own with really high speed blower fans. Not much air is guided or directed through the hood vent. There is way too much turbulence in that area for the air to do anything, imo. Most of the air exited through the bottom of the radiator in all of my tests. I'm not saying it doesn't work, I'm only giving my opinion on the subject matter.
One thing for sure though, is that a ton of hot air vents out of the engine compartment through the hood vent after removing that plastic piece of junk. I also removed the weatherstripping at the rear of the hood/cowl area and my car cools off pretty darn quick. To each their own!
I've raced many fast cars, none of which had hood vents and none of those ever lifted at 160+ mph. It's a good engineering concept, but I don't really see the need for it to be there. I have done several tests of my own with really high speed blower fans. Not much air is guided or directed through the hood vent. There is way too much turbulence in that area for the air to do anything, imo. Most of the air exited through the bottom of the radiator in all of my tests. I'm not saying it doesn't work, I'm only giving my opinion on the subject matter.
One thing for sure though, is that a ton of hot air vents out of the engine compartment through the hood vent after removing that plastic piece of junk. I also removed the weatherstripping at the rear of the hood/cowl area and my car cools off pretty darn quick. To each their own!
Isn't the base of the windshield a high pressure area?
Isn't the base of the windshield a high pressure area?
Maybe on paper! My hood doesn't shake, rattle, roll, move.....nothing! All it does is let the blower whine a little more and also lets a lot of hot air out of the engine bay while driving.Water doesn't get in either and that's because I wash it with my 2700psi pressure washer.
I've raced many fast cars, none of which had hood vents and none of those ever lifted at 160+ mph. It's a good engineering concept, but I don't really see the need for it to be there. I have done several tests of my own with really high speed blower fans. Not much air is guided or directed through the hood vent. There is way too much turbulence in that area for the air to do anything, imo. Most of the air exited through the bottom of the radiator in all of my tests. I'm not saying it doesn't work, I'm only giving my opinion on the subject matter.
One thing for sure though, is that a ton of hot air vents out of the engine compartment through the hood vent after removing that plastic piece of junk. I also removed the weatherstripping at the rear of the hood/cowl area and my car cools off pretty darn quick. To each their own!
Do you have any wind tunnel testing to prove your point? GM's engineers have gone through all the data and I think it is safe to say the vent functions as it should.
Do you have any wind tunnel testing to prove your point? GM's engineers have gone through all the data and I think it is safe to say the vent functions as it should.
Oh it functions, but not well enough IMO, not enough for me to leave it on there. But just like those same Engineers that produced a car with tons of overheating issues, huh? Yeah, they got it all figured out don't they! Also, if those exterior vents worked so well, they wouldn't have installed a secondary radiator for the tranny. Seems to me like they are just throwing parts at it. Problem is, high pressure air becomes turbulent and very difficult to guide through very small openings. Again, to each their own...
Maybe on paper! My hood doesn't shake, rattle, roll, move.....nothing! All it does is let the blower whine a little more and also lets a lot of hot air out of the engine bay while driving.Water doesn't get in either and that's because I wash it with my 2700psi pressure washer.
Shaking or rolling is not a valid test. Tape a bunch of 4" pieces of wool across the back edge
of the hood, and base of the windshield. Drive at reasonable hwy speed and see where they blow.
If they lift up then you're right. If they stay down and/or point downish, it's a high pressure area, and hot air is not exhausting through there.
Hot air will exhaust if you're sitting in traffic, just from the fan blowing.
Oh it functions, but not well enough IMO, not enough for me to leave it on there. But just like those same Engineers that produced a car with tons of overheating issues, huh? Yeah, they got it all figured out don't they! Also, if those exterior vents worked so well, they wouldn't have installed a secondary radiator for the tranny. Seems to me like they are just throwing parts at it. Problem is, high pressure air becomes turbulent and very difficult to guide through very small openings. Again, to each their own...
Sounds like you do not like your car much, huh. I have never bought a track car and never had to upgrade it in some form. Car companies in general cannot make everyone happy because some track them, and some wax them.
01-13-2017, 05:45 PM
Hood heat extractor vent really functional?
