Air circulation in the 'stock' engine bay. - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Falundir · 06-19-2012, 11:05 PM

I've always hated that the mailslot was non functional, so this new toy interests me (http://www.camaro5.com/forums/showthread.php?t=230368), however I am concerned that introducing a way to get more air into the engine bay without extracting the additional hot air might add a complication.

Does anyone have any knowledge on this?

BubbaSS · 06-19-2012, 11:11 PM

I don't think it would be enough air to make much difference, just nice to have it functional.

The Stig · 06-19-2012, 11:15 PM

Yes, forcing air into the engine bay without having any means of letting the air escape will cause problems. Imagine that your pumping air into a pressurized tank, normally these tanks have a blow off valve so that the excess pressure can escape. Without heat extractors you're running without a blow off valve. If you continue to pump air into the tank, it will eventually explode.

EDIT: as the above poster mentioned, it *may* not be enough air to matter. But the same principle applies.

Falundir · 06-19-2012, 11:19 PM

ACS' theory is that it would force out the bottom. I'd kill to see some circulation maps. Don't we have GM engineers on here we could bug? =)

PAUL SS · 06-19-2012, 11:20 PM

Quote:

Originally Posted by stieger

Yes, forcing air into the engine bay without having any means of letting the air escape will cause problems. Imagine that your pumping air into a pressurized tank, normally these tanks have a blow off valve so that the excess pressure can escape. Without heat extractors you're running without a blow off valve. If you continue to pump air into the tank, it will eventually explode.

EDIT: as the above poster mentioned, it *may* not be enough air to matter. But the same principle applies.

However the engine compartment is not a sealed vessel that can maintain any kind of pressure, there is lots ways for air to escape. I do think hood vents would be a good idea as heat rises and they would provide an easy, natural exit for the heat. I too like the idea of making the mailslot somewhat functional.

Synner · 06-19-2012, 11:25 PM

Any lift from that minimal of airflow would likely be negligible unless you have plans to run the texas mile in which case you should be considering aero for high speed stability increases. Don't over think it, get it if you want it although hood vents would move a lot more air and likely improve aero.

matt55 · 06-20-2012, 11:27 AM

Isn't that more of a low pressure zone where the mail slot is?
So it could let hot air out? And not "ram" it in.
Any aero geeks on here?

Intimidator · 06-20-2012, 12:09 PM

I have taken the rubber seal off from around the wiper area under the hood, this seems to allow some of the heat to escape....since this is my daily driver and I drive it alot in the rain and wash it once a week, you would think water would be all over the engine bay without the seal...but it isn't, barely any, if at all!
I have also removed the engine cover to reduce heat...I like the mechanical look!

The_Raging_Bull · 06-20-2012, 12:42 PM

I'm not an an aero geek, but I'm a chemist. The pressure differential created by raming any air requires the system to be sealed. Last time I looked I can see pavement out of the engine bay bottom, so there's no way you're going to do harm under the hood, except to move additional cooling air into the bay, and push hot ai out the bottom.

My guess is it will aide in cooling the engine compartment better, a thermocouple and an electronic thermometer could answer that.

As for those of us who have CAI the possibility that you'll pull in hot under the hood air would be less with this as well.

Ater looking at their website, I hate to rain on any parades; but I favor not messing around too much with airflow and aerodynamics, which Chevy did a significant amount of time optimizing; I'd be interested in knowing EXACTLY how much their products affect the downforces of the car. Did they do any wind tunnel studies to come up with optimized products?

Falundir · 06-20-2012, 01:13 PM

On the aerodynamics.

Giving it thought, in theory I can only see it improving aerodynamics. You are removing a point of resistance that doesn't flow on the front of the car. Mind you the surface area is probably 2-3% of the whole fascia, but allowing air in vs stopping it with a solid surface and no where for it to go seems like a win to me.

However, I think the aero improvement would be measured in thousandths.

The Stig · 06-20-2012, 01:19 PM

Quote:

Originally Posted by lgvenable

I'm not an an aero geek, but I'm a chemist. The pressure differential created by raming any air requires the system to be sealed. Last time I looked I can see pavement out of the engine bay bottom, so there's no way you're going to do harm under the hood, except to move additional cooling air into the bay, and push hot ai out the bottom.

My guess is it will aide in cooling the engine compartment better, a thermocouple and an electronic thermometer could answer that.

As for those of us who have CAI the possibility that you'll pull in hot under the hood air would be less with this as well.

Ater looking at their website, I hate to rain on any parades; but I favor not messing around too much with airflow and aerodynamics, which Chevy did a significant amount of time optimizing; I'd be interested in knowing EXACTLY how much their products affect the downforces of the car. Did they do any wind tunnel studies to come up with optimized products?

They probably didn't do any windtunnel testing. I understand that you can see the pavement from the bottom of the engine bay. But heat rises, so all that hot air is going to be trying to escape from the highest point in the engine bay. The only thing that will be going out the bottom is the cold air (unfortunately).

Synner · 06-20-2012, 01:24 PM

No you're increasing the drag coefficient by having it not flow around the car smoothly. That's why all the new special fuel efficiency packages on cars have shutters that close off openings at highway speeds.

90503 · 06-20-2012, 01:32 PM

Not sure of the mail slot thing, but I bought (but haven't put it on yet) a "belly pan"...Was told it would actually make air circulate better for cooling in stock configuration of engine compartment instead of turbulence from below....and keep the engine compartment cleaner...dunno...

CFD · 06-20-2012, 01:47 PM

Remember that when Chevy first designed the front facia the mail slot was functional but by the time production came it was eliminated, for what reason I'm not sure.

Because the mail slot openning is so small any changes in airodynamics will have absolutely no measureable effect.

When I designed my mailslot scoop I chose to open the whole area not just the small openning behind the trim piece, this allowed for much more air flow. Although my scoop ties into my CAI it could easily be used to add air flow to the engine compartment but I felt the benefits of adding the additionional air to the intake was more beneficial.

06-19-2012, 11:05 PM	#1
Falundir Drives: 2017 1SS 1LE - Hyper Blue, P85DL Join Date: Jul 2011 Location: East Bay Posts: 2,189 View My Garage	Air circulation in the 'stock' engine bay. I've always hated that the mailslot was non functional, so this new toy interests me (http://www.camaro5.com/forums/showthread.php?t=230368), however I am concerned that introducing a way to get more air into the engine bay without extracting the additional hot air might add a complication. Does anyone have any knowledge on this?

06-19-2012, 11:11 PM	#2
BubbaSS WHAT RED LIGHT?! Drives: 2011 Black Camaro 2SS/RS M6 Join Date: Apr 2011 Location: Miami, Florida Posts: 1,115	I don't think it would be enough air to make much difference, just nice to have it functional. __________________ 2011 2SS/RS M6 BLACK - VARARAM NO TUNE INTAKE, MODDED AND PORTED TB, PORTED INTAKE MANIFOLD, VITESSE THROTTLE CONTROLLER, DOUG THORLEY LT'S, CATLESS, X-PIPE, 25" STAINLESS WORKS RETRO CHAMBERED MUFFLERS, CUSTOM 2.5" MANDREL BENT EXHAUST, RICHMOND 4.10 GEARS, CUSTOM CAM (231/242 @ 114LSA), MUSTANG DYNO TUNED BY TORQ, 20% CERAMIC TINTS, EIBACH PROKIT SPRINGS 1" DROP, HAWK PERFORMANCE CERAMIC BRAKES, NITTO INVO TIRES, HYDROCARBON TAIL LIGHT AND FOG LIGHT BEZELS BY EMBLEMPROS, METRA DASH KIT, JVC KW-AV71BT, PHOENIX GOLD iAMP GM1, PASSPORT QI45 - 450 RWHP 415 RWTQ

06-19-2012, 11:15 PM	#3
The Stig knows 2 facts about ducks Drives: ...and they're both wrong Join Date: Aug 2009 Location: The HMS Invincible Posts: 25,072 View My Garage	Yes, forcing air into the engine bay without having any means of letting the air escape will cause problems. Imagine that your pumping air into a pressurized tank, normally these tanks have a blow off valve so that the excess pressure can escape. Without heat extractors you're running without a blow off valve. If you continue to pump air into the tank, it will eventually explode. EDIT: as the above poster mentioned, it may not be enough air to matter. But the same principle applies. __________________

06-20-2012, 11:27 AM	#7
matt55 Drives: CTS-V Join Date: Aug 2008 Location: Raleigh NC Posts: 1,069	Isn't that more of a low pressure zone where the mail slot is? So it could let hot air out? And not "ram" it in. Any aero geeks on here? __________________ 10.8@130.8 610 whp, CAI, 2.5, E85, id850 on street tires.

06-20-2012, 12:42 PM	#9
The_Raging_Bull Raging Bull Reborn Drives: '09 CGM Z063LZ '15 RH Z/28 #0631 Join Date: Mar 2012 Location: Broken Arrow OK Posts: 765 View My Garage	pressure differential I'm not an an aero geek, but I'm a chemist. The pressure differential created by raming any air requires the system to be sealed. Last time I looked I can see pavement out of the engine bay bottom, so there's no way you're going to do harm under the hood, except to move additional cooling air into the bay, and push hot ai out the bottom. My guess is it will aide in cooling the engine compartment better, a thermocouple and an electronic thermometer could answer that. As for those of us who have CAI the possibility that you'll pull in hot under the hood air would be less with this as well. Ater looking at their website, I hate to rain on any parades; but I favor not messing around too much with airflow and aerodynamics, which Chevy did a significant amount of time optimizing; I'd be interested in knowing EXACTLY how much their products affect the downforces of the car. Did they do any wind tunnel studies to come up with optimized products? Last edited by The_Raging_Bull; 06-20-2012 at 12:52 PM.

06-19-2012, 11:19 PM	#4
Falundir Drives: 2017 1SS 1LE - Hyper Blue, P85DL Join Date: Jul 2011 Location: East Bay Posts: 2,189 View My Garage	ACS' theory is that it would force out the bottom. I'd kill to see some circulation maps. Don't we have GM engineers on here we could bug? =)

06-19-2012, 11:25 PM	#6
Synner Drives: cars Join Date: May 2011 Location: Oversneeze Posts: 4,542	Any lift from that minimal of airflow would likely be negligible unless you have plans to run the texas mile in which case you should be considering aero for high speed stability increases. Don't over think it, get it if you want it although hood vents would move a lot more air and likely improve aero.

06-20-2012, 12:09 PM	#8
Intimidator Drives: 69 GTO, 05 GTO, 2018 Silver ZL1 Join Date: Jan 2012 Location: Springfield, OH Posts: 847	I have taken the rubber seal off from around the wiper area under the hood, this seems to allow some of the heat to escape....since this is my daily driver and I drive it alot in the rain and wash it once a week, you would think water would be all over the engine bay without the seal...but it isn't, barely any, if at all! I have also removed the engine cover to reduce heat...I like the mechanical look!

06-20-2012, 01:13 PM	#10
Falundir Drives: 2017 1SS 1LE - Hyper Blue, P85DL Join Date: Jul 2011 Location: East Bay Posts: 2,189 View My Garage	On the aerodynamics. Giving it thought, in theory I can only see it improving aerodynamics. You are removing a point of resistance that doesn't flow on the front of the car. Mind you the surface area is probably 2-3% of the whole fascia, but allowing air in vs stopping it with a solid surface and no where for it to go seems like a win to me. However, I think the aero improvement would be measured in thousandths.

06-20-2012, 01:24 PM	#12
Synner Drives: cars Join Date: May 2011 Location: Oversneeze Posts: 4,542	No you're increasing the drag coefficient by having it not flow around the car smoothly. That's why all the new special fuel efficiency packages on cars have shutters that close off openings at highway speeds.

06-20-2012, 01:32 PM	#13
90503 Drives: 2011 2SS/RS LS3 Join Date: Nov 2011 Location: Torrance Posts: 14,564	Not sure of the mail slot thing, but I bought (but haven't put it on yet) a "belly pan"...Was told it would actually make air circulate better for cooling in stock configuration of engine compartment instead of turbulence from below....and keep the engine compartment cleaner...dunno...

06-20-2012, 01:47 PM	#14
CFD Drives: 2SS/RS L99 BLACK Join Date: Apr 2010 Location: Franklin , MA Posts: 6,696	Remember that when Chevy first designed the front facia the mail slot was functional but by the time production came it was eliminated, for what reason I'm not sure. Because the mail slot openning is so small any changes in airodynamics will have absolutely no measureable effect. When I designed my mailslot scoop I chose to open the whole area not just the small openning behind the trim piece, this allowed for much more air flow. Although my scoop ties into my CAI it could easily be used to add air flow to the engine compartment but I felt the benefits of adding the additionional air to the intake was more beneficial.