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-   Performance, Brainstorming & Tuning (https://www.gmforum.com/performance-brainstorming-tuning-96/)
-   -   Functional? ram air hood (https://www.gmforum.com/performance-brainstorming-tuning-96/functional-ram-air-hood-266140/)

alexcoqui 10-15-2007 07:31 PM

I read the article, & l have to say that it surprized me. Now I understand what all the fuzz is about.
All this time when Ive heard the term "ram air", I allways thought that it ment: to ram fresh air in to the filter compartment. :roll:
I dont think that Ive ever heard or read Pontiac sujesting otherwise. Nor had I asumed or think that someone would asume that poking a hole in your hood will give any type of extra compresion to the incoming air.
Im making a drawing of what Im doing so that it will be clearer.

willwren 10-15-2007 08:19 PM

Not dissin' you here. ;)

Just trying t clarify terms and make sure people understand what you're actually doing, and what NOT to expect.

A true ram-air hood would be on a NON-supercharged or NON-turbo car, routed to the airbox, and would net probably 5-10hp above 100mph.

Now on the flip side, I run ram-air COOLING scoops and ducts, with a VENTED hood.

BonneMeMN 10-15-2007 10:30 PM

Best use of ducting or an open hood is to help feed air into the airbox, etc.. It's much easier to get a cooler charge with a fresh supply as opposed to the inlet just sitting in the fender area sucking the relatively stagnant engine bay air.

But as mentioned, pressurizing isn't gonna happen really..

BillBoost37 10-16-2007 08:09 AM

Either way.. Pontiac has used and still uses the term Ram Air on some of their models. While it's not necessarily netting huge gains.. it's a term that's used.

Similarly when Bill W says he's got ram air cooling for his motor.. I see it as air flow direction and nothing more as it's not being rammed, merely directed to a specific open area of the engine bay.

I say..use the term if you'd like...we are reminded constantly that true ram air is a myth and you made one heck of an awesome hood there.

willwren 10-16-2007 08:20 AM


Originally Posted by BillBoost37
Similarly when Bill W says he's got ram air cooling for his motor.. I see it as air flow direction and nothing more as it's not being rammed, merely directed to a specific open area of the engine bay.

And that's where you'd be wrong. During testing, Katie and I had rags stuffed in each OUTLET for the first phase of testing. The backpressure blew the hoses off the scoops down below. It's not just direction. The scoops were designed to build pressure. Based on surface area compared to the delivery tubes, it's about 3:1. There's a significant amount of velocity developed before the air enters the engine bay.

BillBoost37 10-16-2007 08:29 AM

Let's attempt to keep this on topic for Alex as I was using yours as an example only. However according to the fact that this air doesn't go into a box or intake and it's under 100mph ...there is no ramming being done. You built pressure by blocking the end of a tube.. and the weakest link allowed the air to escape. There can be airflow w/o ram air. ;)

alexcoqui 10-16-2007 08:51 AM

4 Attachment(s)
First of let me say that Ive never felt like this was personal, I know this is one of those topics that are allways been discused in this forum. (like the Bose plugs or the 3" exhaust) :lol: Im glad you people are here to tell us all of this things, cause every time I come in here and read, I lern a lot about my car. So thank you for that.

But, back on topic:

Attachment 40694
this is what I had when the hood was done. You can see 3 lines, one is the bottom of the hood, the other is the hoods top, & the third one is the one we added to make the scoop.

Attachment 40695
What I did was to cut a rectangular hole on the 2 bottom ones. then I added a wall diagonally so that the incoming air will go down in to the engine compartment. another thing I did was to round the other side (it seem like a good idea at the time).

Attachment 40696
so this is how the air is soposed to bejave.

Attachment 40697
& these are the plans. Im thinking on building this out of fiberglass. & I will use the same filter & tube that I got from Intense. I need to cover the box with somthing that will stop the heat from coming in to it.

Im still working on Ideas. Im doing stuff out of fomeboards. & when Im happy with it Ill fiberglass it. As soon as I have something, Ill take some pics.

alexcoqui 10-16-2007 09:03 AM

3 Attachment(s)
Attachment 40691
Here's another picture of the underside. I cut where it was flat so that later I can make a good seal when I add the box. & when you close the hood the hole is between the pulleys & the radiator. Oh & is not centered. its a closer to filter's side.

Attachment 40692
Here you can see better what I did to rerouthe the air in to the engine. Its completly sealed so that the air can only go down.

Attachment 40693
you can see it trough the scoop.

slickbonny 10-16-2007 09:09 AM

wow! that hood looks f^*#in sweet. i want one just for the looks. dont care about ram air.

willwren 10-16-2007 10:23 AM


Originally Posted by BillBoost37
Let's attempt to keep this on topic for Alex as I was using yours as an example only. However according to the fact that this air doesn't go into a box or intake and it's under 100mph ...there is no ramming being done. You built pressure by blocking the end of a tube.. and the weakest link allowed the air to escape. There can be airflow w/o ram air. ;)

Funny how you ask to keep it on topic, but continue to argue. This is directly related to the topic being discussed. It is VERY EFFECTIVE ram-air COOLING as I stated above, and was specifically designed to be just that. I don't have to block the end of the tube to build pressure in the delivery tube. It's 2-3x incoming pressure naturally. There IS ramming being done. I think you're misunderstanding the definition of Ram Air yourself. Even Pontiac's misrespresented Ram Air designs build pressure and flow. It's just not sufficient for developing horsepower (can't overcome the natural draw of air in a NA application). I'm not using it for induction.

My scoops are larger than the tube by design.

Posted: Sat Mar 20, 2004 6:24 pm Post subject: Ram air done, complete, tested. Lots of pics (not 56k)


Katie and I took the car out to test today (Pooky is in CA at cheerleading nationals). Did 6 runs total. First 3 were with both ducts plugged in the engine bay (outlet ends) with clean rags, and tape to hold them in against any pressure. 3 different speeds (30mph, 45mph, 60mph) recording outside air temp, IAT temp, and SC temp (taken just under the mesh at the top of the SC next to the TB). We taped this thermometer (Fluke) to the windshield so we could see it, and took IAT measurements from the Actron scantool. Ambient air temp was taken from the Climate control.

We then stopped the car to unplug the ducts. Funny, the pressure at the scoops built up to the point that it popped the air hoses off the scoops under the car. This answered the pressure/flow question for me. We got back in and ran the same test at the same speeds, recording the same temps. Keep in mind, this was after full heat saturation of the engine/trans.

Our data:

ducts plugged (no ram air)
Speed----------Air temp-----------IAT temp------------SC temp
30-----------------58--------------------92--------------------93
45-----------------59--------------------95--------------------91.6
60-----------------60--------------------90--------------------81.2

ducts unplugged (ram air flowing)
Speed----------Air temp-----------IAT temp------------SC temp
30-----------------61--------------------86--------------------81
45-----------------61--------------------72--------------------80
60-----------------61--------------------70--------------------70

As you can see, it made quite a difference. I'm basically running both ducts at 10° above ambient temps, with a 10-20° reduction in temps across the board.

We then speed-tested the mounting up to 115mph, with no problems. The sprayed on bedliner coating is tough. Not a chip or ding, but we did have dead bug guts inside the scoops, and a dead wasp in the SC cover mesh
Alex can benefit in the same manner. While the amount of flow and pressure from my scoops isn't sufficient to develop horsepower (if that's what I intended), it does show there is benefit to using it for cooling instead of induction. In order to develop higher flow and velocity, he can take some of this into his design while selecting downstream components.

This is all very valuable information, not just for Alex, but for anyone else considering something like this.


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