Functional CF hoods
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Joined: 06-04-07
Posts: 2,530
Likes: 1
From: Los Angeles, CA
I'm running a heat extraction hood by import trenz
I didn't see any difference in temps. Air may flow a bit better through the engine bay... but as far as IAT1 and 2s temps aren't affected.
It's more for looks than anything really...
I didn't see any difference in temps. Air may flow a bit better through the engine bay... but as far as IAT1 and 2s temps aren't affected.
It's more for looks than anything really...
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Joined: 03-26-06
Posts: 2,271
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From: Michigan
Same as he said, I haven't noticed any significant drops in IAT2's (maybe a few degrees) , but it looks good, and the blower whine is a little louder now
VIS CF Invader hood (bought from illstreet.net via carbonfiberhoods.net)
VIS CF Invader hood (bought from illstreet.net via carbonfiberhoods.net)
Banned
Joined: 06-04-07
Posts: 2,530
Likes: 1
From: Los Angeles, CA
I bought my thru
www.ngkits.com (best price I found)
And waited a month for it to ship... (shipping company lost it)
It is also available thru
www.cobalt-addiction.com
and if you google IMPORT TRENZ, you can find it there too.
Remember when purchasing FIBER GLASS hoods, they are mostly not prepped for use.
You will have to spend EVEN more money to have them blocked, primered, and painted to rid of any waves, dimples, or any other imperfections. Even then, some waves are still visible...
www.ngkits.com (best price I found)
And waited a month for it to ship... (shipping company lost it)
It is also available thru
www.cobalt-addiction.com
and if you google IMPORT TRENZ, you can find it there too.
Remember when purchasing FIBER GLASS hoods, they are mostly not prepped for use.
You will have to spend EVEN more money to have them blocked, primered, and painted to rid of any waves, dimples, or any other imperfections. Even then, some waves are still visible...
Senior Member
Joined: 03-26-06
Posts: 2,271
Likes: 0
From: Michigan
And the LSJ, LNF, and base ecotec engines would all ideally have their vents in locations that removed the most heat for that particular app.
i.e. The turbo guys could give a **** less if hot air is removed from the intake side of the engine bay, and us LSJ guys would rather have cool air coming across our blower/intercooler than on the exhaust side of the engine
Banned
Joined: 06-04-07
Posts: 2,530
Likes: 1
From: Los Angeles, CA
Exactly...
My vents sit just behind the blower. Cool air passes over the blower and then escapes out the vents as the air heats up. Pretty much useless, but who cares it looks nice and is light weight.
These hoods are useless for IAT1 OR IAT2 readings. If you want to cool IAT2, do what the STI does. Have a hood scoop thats mounted directly above an intercooler. Then you will have a for sure decrease in IAT2 temperature readings.
My vents sit just behind the blower. Cool air passes over the blower and then escapes out the vents as the air heats up. Pretty much useless, but who cares it looks nice and is light weight.
These hoods are useless for IAT1 OR IAT2 readings. If you want to cool IAT2, do what the STI does. Have a hood scoop thats mounted directly above an intercooler. Then you will have a for sure decrease in IAT2 temperature readings.
Senior Member
Joined: 02-03-08
Posts: 3,454
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From: Port Perry Ontario
Data to back what you say? As I can say with near 100% certainty no-body has ever tested an aftermarket hood on a cobalt in a REAL wind tunnel. I don't doubt that one particular vent design proves to be more efficient in general, but these set-ups have not been tested on a cobalt, much less on their efficiency at different vent positions.
And the LSJ, LNF, and base ecotec engines would all ideally have their vents in locations that removed the most heat for that particular app.
i.e. The turbo guys could give a **** less if hot air is removed from the intake side of the engine bay, and us LSJ guys would rather have cool air coming across our blower/intercooler than on the exhaust side of the engine
And the LSJ, LNF, and base ecotec engines would all ideally have their vents in locations that removed the most heat for that particular app.
i.e. The turbo guys could give a **** less if hot air is removed from the intake side of the engine bay, and us LSJ guys would rather have cool air coming across our blower/intercooler than on the exhaust side of the engine
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Joined: 03-26-06
Posts: 2,271
Likes: 0
From: Michigan
there has been endles windtunnel work done on cobalts, but for sure the aftermarket guys never go there....i have been in the tunnel, end of story. So choose your statements carefully. YOu never know who you meet up with on forums. THe thing is, its not an issue of letting air in, its letting air out; thats the key...when air goes over the hood and hits the base of the windshield, it comes back forward about 12-14 inches or so. The turbulence here is powerful enough to lift the base of a hood, and can cause windshield washer fluid squirted out of a hood mounted nozzle to never hit the windshield; the underhood pressure is enough the break a fiberglass hood at Daytona at 140 + speeds. I dont know about your cobalt, but redlines can muster 140 mph.
Obviously we know the point of a hood vent (on our FI balts anyways) is to pull air out from under the hood, the only place I'd want to force air is into my drivers side fender. You have yet to provide any REAL DATA to show me that the extractor style of hoods are the "least efficient" design to do so,
You also have no Idea who you will run into on a forum. I am a mechanical engineer, and know the cost of REAL wind tunnel work and CFD analysis. Suffice to say, my statement holds true, you have not tested airflow on the vents you are talking about on a cobalt in a wind tunnel. I have been in wind tunnels as well. The largest in the country actually while I was working in the aerospace field. But nobody, short of GM themselves has dropped the coin needed to put a balt in a wind tunnel, and do real fluid and aerodynamic analysis.
Regardless, all e-cockblockery aside, it's a moot point. We put hoods on these cars, for the looks and weight savings,, any air they pull from the engine bay is just an added bonus. We have real cooling mods to bring those IATs down
Sure my cobalt and your redline can do 140. But what's the point? You can't hit that in a 1/4 mile, so who cares? My old mans truck could do 140 with a long enough road.
Didn't you know? Canadians have their redline's and cobalts at Daytona all the time apparently.
That priceless tidbit of info could just save your life, next time your balt takes a wrong turn and ends up on the back stretch at daytona
Last edited by SS33; Jul 23, 2008 at 02:59 PM. Reason: Automerged Doublepost
Senior Member
Joined: 02-03-08
Posts: 3,454
Likes: 1
From: Port Perry Ontario
You have been in a wind tunnel with a cobalt to do this testing?
Obviously we know the point of a hood vent (on our FI balts anyways) is to pull air out from under the hood, the only place I'd want to force air is into my drivers side fender. You have yet to provide any REAL DATA to show me that the extractor style of hoods are the "least efficient" design to do so,
You also have no Idea who you will run into on a forum. I am a mechanical engineer, and know the cost of REAL wind tunnel work and CFD analysis. Suffice to say, my statement holds true, you have not tested airflow on the vents you are talking about on a cobalt in a wind tunnel. I have been in wind tunnels as well. The largest in the country actually while I was working in the aerospace field. But nobody, short of GM themselves has dropped the coin needed to put a balt in a wind tunnel, and do real fluid and aerodynamic analysis.
Regardless, all e-cockblockery aside, it's a moot point. We put hoods on these cars, for the looks and weight savings,, any air they pull from the engine bay is just an added bonus. We have real cooling mods to bring those IATs down
Sure my cobalt and your redline can do 140. But what's the point? You can't hit that in a 1/4 mile, so who cares? My old mans truck could do 140 with a long enough road.
Didn't you know? Canadians have their redline's and cobalts at Daytona all the time apparently.
That priceless tidbit of info could just save your life, next time your balt takes a wrong turn and ends up on the back stretch at daytona
Obviously we know the point of a hood vent (on our FI balts anyways) is to pull air out from under the hood, the only place I'd want to force air is into my drivers side fender. You have yet to provide any REAL DATA to show me that the extractor style of hoods are the "least efficient" design to do so,
You also have no Idea who you will run into on a forum. I am a mechanical engineer, and know the cost of REAL wind tunnel work and CFD analysis. Suffice to say, my statement holds true, you have not tested airflow on the vents you are talking about on a cobalt in a wind tunnel. I have been in wind tunnels as well. The largest in the country actually while I was working in the aerospace field. But nobody, short of GM themselves has dropped the coin needed to put a balt in a wind tunnel, and do real fluid and aerodynamic analysis.
Regardless, all e-cockblockery aside, it's a moot point. We put hoods on these cars, for the looks and weight savings,, any air they pull from the engine bay is just an added bonus. We have real cooling mods to bring those IATs down
Sure my cobalt and your redline can do 140. But what's the point? You can't hit that in a 1/4 mile, so who cares? My old mans truck could do 140 with a long enough road.
Didn't you know? Canadians have their redline's and cobalts at Daytona all the time apparently.
That priceless tidbit of info could just save your life, next time your balt takes a wrong turn and ends up on the back stretch at daytona
Senior Member
Joined: 03-26-06
Posts: 2,271
Likes: 0
From: Michigan
And good day to you, but first,,,
If you ever feel like coming back and answering a question, or sharing some of what you know I'll be here. If you have something real to show, I'm all about it. Telling us the speed at which a fiberglass hood will break on a C5, and that hood pins are required to hold a cobalt hood together at Mach 1. These things have Nothing to do with the topic at hand. I'm not trying to be a dick, just looking for something to substantiate the claim, You made.
But the bottom line is, even at 4k a day for your wind tunnel, (which is very cheap) and we'll assume you performed the CFD analysis yourself ( you do know what CFD is don't you?)
You ended up with a cheap looking add-on hood vent? Why drop the coin on R&D if you weren't going to make real hoods? Seriously though, am I missing something here? These are the pics you directed us too,
If you ever feel like coming back and answering a question, or sharing some of what you know I'll be here. If you have something real to show, I'm all about it. Telling us the speed at which a fiberglass hood will break on a C5, and that hood pins are required to hold a cobalt hood together at Mach 1. These things have Nothing to do with the topic at hand. I'm not trying to be a dick, just looking for something to substantiate the claim, You made.
But the bottom line is, even at 4k a day for your wind tunnel, (which is very cheap) and we'll assume you performed the CFD analysis yourself ( you do know what CFD is don't you?)
You ended up with a cheap looking add-on hood vent? Why drop the coin on R&D if you weren't going to make real hoods? Seriously though, am I missing something here? These are the pics you directed us too,
Member
Joined: 10-08-07
Posts: 351
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From: Saint John
