07blackg5

iTrader: (8)

Your statement would be much more pronounced if you included a picture of your certifications hanging on the wall.

Henry3959

Here's your empirical data.... There is a high pressure at the back of the hood / cowl

Henry3959

That was an honest reply.

07blackg5

iTrader: (8)

You aren't looking at the whole picture. What about low speeds/idling? It most definitely will help heat escape better that a "sealed" hood. Also, just because heat isn't "coming out" at that point while at speed due to the high pressure area, doesn't mean there wont be a cooling effect.

The entire reason air flows through the radiator is because there is a high pressure area on the outside side, and a low pressure area on the inside side. The air flows through from the high pressure to the low pressure side, and then out through the low pressure area under the car. That's the main point of the air dam under the radiator, to help increase the high pressure area in front of the radiator and increase the low pressure area behind the radiator. It helps draw the air through the radiator, rather than straight down to the under car low pressure area.

The cowl may have a high pressure on the outside, but it can help draw cool outside air IN to the engine bay, and out through the low pressure under the car. Hence the name cowl INDUCTION.

Henry3959

You're correct... I am not looking at the whole picture... I am looking at the issue the OP is having and he isn't complaining about heat at idle. The vents he wants to install are in a low pressure area where they will function.

07blackg5

iTrader: (8)

Your statement was directly aimed at a cowl at the hood-windshield not functioning because it is a high pressure area. But okay, you're obviously way too smart for my feeble mind to comprehend.

Henry3959

Cowl Induction was not intended to remove heat from the engine bay... It was used as a cold air source for the engines induction system.

Courtesy of: mechanics stack exchange

While I won't say a cowl was never used for cooling the engine bay (I'm sure someone has done that), it really won't do much for cooling (as in to draw air out from and engine bay) and here's why:

As your vehicle is travelling down the road the air travelling around different parts of the vehicle creates high pressure areas. The two biggest of these are the front end (grill area) and the windshield. The base of the windshield especially, because this is where the air starts to make its turn upward to go over the top of the car. Because of this, there is basically no way for there to be any heat extraction from this area. You can, however, draw air into the engine from there. This high pressure area not only provides a source of denser air, it also provides cooler air, all of which helps produce horsepower. This was GM's theory behind the Chevelle Cowl Induction hood.





There are three main purposes for a cowl hood:

Aesthetics
Provide clearance for under hood engine parts
To locate a source of cold air for the intake at the base of the hood
If a manufacturer has wanted cooling effects from the hood area, they will usually use an extractor to do this. Heat extractors work by using the venturi principle, where the air is sped up over a lip and when it gets over the lip, it slows down and creates an slight vacuum at the port, which pulls air out from under the hood.

Henry3959

My point was you do not extract air out from under the hood by lifting the rear of the hood up or by leaving your wiper tray out. What the OP is doing will work best for his purpose. Looking forward to the finished results.

Henry3959

Yeah that's all good and great but can you rebuild a Turbo Encabulator

royce777

iTrader: (29)

can you draw this with a picture of a cobalt?

Henry3959

That's not my drawing... Plenty found via google if it matters.

"As your vehicle is travelling down the road the air travelling around different parts of the vehicle creates high pressure areas. The two biggest of these are the front end (grill area) and the windshield. The base of the windshield especially, because this is where the air starts to make its turn upward to go over the top of the car."

royce777

iTrader: (29)

I think it would look something like this.

PS drawing is not to scale.

Henry3959

And this is why we will wait for colodude18's results.... Some peoples Kids
The inmates are running the asylum again.

Slowbalt2000

iTrader: (1)

With my eyes closed.




This thread got derailed quick

Henry3959

Funny how it is the same people every time that start taking threads off track... I just want to see the results.

exninja

iTrader: (1)

You forgot the downforce from the spoiler. Worth at least 10hp of downforce.

exninja

iTrader: (1)

It's only the "same people every time" that post at all on this forum...

Slowbalt2000

iTrader: (1)

this.

there are only so many active users here.

Kolt

Can we just agree to disagree and leave it. Too much drama for the few of us that's left.

jdbaugh1

iTrader: (1)

Empirical data would be more like a picture of a Cobalt in a wind-tunnel with relative pressure indicators under the hood and at the back of the hood where I am asking about. If the flow is laminar enough it might be an area of "higher" pressure relative to the rest of the flow around the car but it only needs to be lower than the pressure under the hood. If you see all the red arrows at the front of the car in your very generic oversimplified graphic, you can imagine what the pressure under the hood may be. Do you have any actual empirical, as in measured in real life scenarios, data that shows the differential pressure between the cowl location and under the hood in the same area on a Cobalt? If not than you don't have what I'm looking for you just have generalizations.

Edit: Btw, not saying the theory is wrong, I just like to see real data. After searching it looks like the only way to get that is to gather it myself. Looks like a quick experiment with some strings, tape and a go-pro would do it.

Henry3959

Out of the dozens of pics i found i chose that one with you in mind
Empirical data.... fluid dynamics.... you crack me up

jdbaugh1

iTrader: (1)

So you're saying people don't do physical fluid dynamics tests?

Slowbalt2000

iTrader: (1)

We can wait until Adrian tests this new hood he is making. Then we will have real data.

jdbaugh1

iTrader: (1)

According to HGT that doesn't exist. Fluid dynamics only exist in theory and the characteristics are not measurable.

ProfDNS

Can we just agree OP has great skills with the dremmel if he freehanded it?