Alternative air induction methods

Cougar Community Classic Cougar Speed Shop
1

For whatever reason, once I realized that with the hood I’m getting for my Cougar is one I will free to drill, or in this case cut, I got a bee in my bonnet for switching to an alternative air induction scheme.

The first thing I thought was ram air via a functional scoop as was available on cougars in 68. But with all I’ve read and heard from people who had them about how rain becomes a problem, even though I don’t deliberately take my cougar out in the rain, I was still a little put off on the idea.

What I’ve come up with is pretty interesting, to me anyway. All I have are rough drawings so far, and a layout in my mind that’s a little fuzzy still but fairly well laid out.

I want to build a cowl induction rise to the hood, and have a plan for trapping water at least a bit and routing it to drain into an area that doesn’t have anything sensitive like anything electrical or the exhaust manifolds or anything.

But that’s not enough! I also want to implement ram air, just not via the standard method. I’m going to take the front valence from the donor car and cut out most of the center area of it, and build (or buy if I can find the right part) an air collector for each side that has something like 3" tall and maybe 1.5’ wide opening that funnels down to a hose of diameter that is TBD. The hoses would then each run under the core support (that’s the name of the structural member the radiator sits on, right?) and up along the inner fender walls and go to holes in the base of the air cleaner housing. I’ll be using the air cleaner housing from the donor car if it has one and it’s in good enough shape to work with.

The thing that seems really good about that method of achieving ram air is that with the intake scoops that low down, under the bumper, and the air cleaner much higher up, then any rain or road water that gets taken in the scoops would have to fight gravity to get into the carb. So, hopefully it reduces that issue.

Also, totally gonna add the chin spoiler which hopefully can both generate a little downforce up front and also push more air into the ram inlets

Anyone ever done this before, use both cowl and ram air at the same time? Any issues with it? My first thought was that either the cowl or ram intakes might have much more air pressure than the other, so one might end up trying to push air out the other, reducing the effectiveness of one or even both. But then when I think about it, the point where the two systems merge is inside the air cleaner, and at that point, doesn’t the vacuum created at the carb’s air inlet create a very clear path of least resistance? So I’m hoping that maybe the two systems can play nice together and depending on speed, maybe one will outperform the other or vice versa, but still having both will push a little more air in than either one would on its own.

One thing I forgot to mention, for the cowl induction aspect, I plan on building a riser on top of the hood, which will be sealed everywhere except 1) at the cowl, because, duh, and 2) at the hole I will have cut into the hood pretty much exactly the same as how the ram air setup works, a seal between the air cleaner and the hood, just in this instance the scoop is backward facing instead of forward.

And for both systems, I am going to implement some sort of screen, maybe even start off at $0 using screen from a window or door I have sitting around the basement. Last thing I want is to get myself set up in a way where I’m constantly changing the air filter because its full of Mosquitos, moths, bees etc that my fancy new intake system eats for lunch.

This is where, in case it isn’t painfully obvious, I point out that I know just about nothing about actual applications of alternate air induction methods. Very little. So I am totally prepared to be told that I am an idiot and my plan makes no sense.

Any input is greatly appreciated! I mean any. Thoughts on the dual system setup, suggestions of materials to use, things to watch out for, any insight you have, please do share.

Thanks!!

Scott

2

Oh, goody. Aero questions.

Here’s what I think:

  1. If you’re using a carburetor, you need to remember that “ram-air” wasn’t so much pressurizing the area around the carb throat, but it was an effort to bring cooler and denser air to the mix. Basically more O2 per gulp of air volume. Ala trans-am cars and nascar back then.

  1. You can use an air to air intercooler to keep the atmosphere (wet, rainy, disgusting atmosphere) chilling the intake air below air temp (more 02 per cm^3!!!), and the intake charge dry (no rain issues). These parts are already around and fabricated, or at least you can get an idea of what to make and how to get it going.
    Turbo and supercharged cars use these in the grille or scoop like you’re describing. Here’s one:Intercoolers | MAPerformance - MAPerformance??utm_source=google&utm_medium=Product_Search&utm_campaign=google_base&gclid=CNSJoLXTnrgCFWdo7AodjyIA3A
    You can also do an air/water intercooler using a cool water jacket to cool the intake air.
    And if you don’t care about filtered intake air, you can subtract two headlights and use the headlight holes without having to cut the chin spoiler.
    The grille are is high pressure, since the frontal area is so large on these cars. Be like Tiny Lund.

  1. Do a little engineering math to make sure your ducts/scoop don’t just look like they’ll work in terms of cfm. Math it out and be sure. :beerchug:
3

Cold air induction is not a new or foolish idea. Nearly all newer cars have it…Here’s a page of pics to get those creative juices flowing; https://www.google.com/search?q=dual+inlet+air+intake&client=firefox-a&rls=org.mozilla:en-US:official&channel=np&tbm=isch&tbo=u&source=univ&sa=X&ei=ngjaUcDbBIPa9AT4nYCADg&ved=0CHMQsAQ&biw=1024&bih=635#facrc=_&imgdii=_&imgrc=63FVV3aOjZVEPM%3A%3B-0-3aAvwLMZqEM%3Bhttp%253A%252F%252Fi43.photobucket.com%252Falbums%252Fe383%252Fblndyhb%252FMomAuntTinaandUncleJohnny004.jpg%253Ft%253D1247814427%3Bhttp%253A%252F%252Fwww.forabodiesonly.com%252Fmopar%252Fshowthread.php%253Ft%253D63441%3B800%3B600

4

I found the article you were referencing (here AutoSpeed - Technology, Efficiency, Performance) and although it uses a different car than mine with a much more aerodynamic body shape, what they found was that the highest positive pressure was built up exactly where I’ve been planning to locate my inlets, which is probably good news. And with the addition of a chin spoiler and the location of the inlets directly above it, I am inclined to believe there will be even more of a boost of air volume brought in at this already ideal location. :slight_smile:

Now that I know to search for the term “positive pressure”, which should have been obvious to me, I’m sure I can do even better research. Thanks for the tips!

5

Scott, I’m just a little confused by the two systems. Cowl and Ram Air. Don’t both systems really just offer cool air induction? Why the need for both? Either choice should be good.

The 1983-1985 Mustang used a twin snorkle air cleaner with duct work leaving the engine compartment from each snorkle. It was a pretty good looking air cleaner set up.

Using you front valance idea you could do something like the 1968 442 raim air set up. It came out under the front valance and could be intergrated into a front chin spoiler on your Cougar.

Lets not forget Hero! Mark did a fine job with his cowl hood.

I just wanted to give you some food for thought for your system.
Steven

6

Yes I should have mentioned, the carb is a 4v 600cfm Edelbrock 1406. And while my aim with both air intake systems is to bring in cooler air from outside the engine bay, I wouldn’t mind any pressure boost, however slight it may be, as from what I’ve read this can have a very mild supercharging type effect. I expect more of that from the under-bumper ram system than from the cowl system, but I’ll take whatever I can get from both!



While a good intercooler is surely a time-tested solution, it’s really not in my budget. I’m trying to do this for as close to $0 as possible, really. If I can sell off enough parts from my donor car to break even on what I paid for it, and essentially get the hood and front valence to chop up (and a few other parts) for free, that will be a big help. I’m already going to have to outlay cash on a number of other things to make this happen, so I don’t think anything as fancy as an intercooler is in my future anytime soon.

I did consider removing a pair of headlights, but there are a lot of problems that immediately became apparent. First off the headlight doors would have to be modified to be free flowing, or left open all the time, neither of which is very appealing to me. Second, the area behind the buckets is really cramped, so there isn’t a good route for a decent sized hose without having to cut through some of the support structure in the front, and I am aiming for as close to a 100% reversible mod as I can get (hence not using my existing hood or front valence, which will be removed, wrapped up, and stored in their current very good condition). The headlight bucket approach is a time tested one, but it’s not in the cards for me here.

My wife just graduated with honors getting a degree in BioPhysics, she really is a science wiz. I’m sure that she will be able to handle the math in her sleep. I could do it myself, I know, but getting her involved just makes it cooler. And when it comes to fluid dynamics and diff eq and all that junk, she really is light years ahead of my anyway.

The aero/pressure thing I am most curious to learn about is the relationship between the surface area of the inlet openings in the valence and the hose diameter I’ll use to get back to the air cleaner base. They’ll essentially be like very short funnels, but with a rectangular opening funneling back to a round hole for the hose. Kinda like the picking-up-water attachment you might use with a shop vac. And in fact, for all I know, that could end up being a prefabricated part that I could buy for cheap and use here, something like this:

http://www.amazon.com/gp/aw/d/B002BFSK6I/ref=mp_s_a_1_6?qid=1373248619&sr=1-6&pi=AA160

I’ll have to look around a lot and see if I can find one with as big of an open face area as I have in mind, of course not until my wife runs some numbers for me. :slight_smile:

7

My thinking is that either one is good, and having both of them may be better as the aero performance might vary with speed, giving one an edge over the other in terms of pressure it can create on the cool air that’s being brought to the carb. I’m absolutely sure there isn’t a NEED for both, but I am assuming that having both will be as good as having either one, and possibly even better.

That’s the idea of where the hoses will attach to the air cleaner base, but instead of routing to the wheel wells and instead of being a rigid assembly like that, it will use hoses that run across to the inner fenders like that but then move downward, under the radiator support, to inlets in the area that is more or less where the license plate mount is (I’ll be ditching my front license plate)

That’s pretty much exactly what I have in mind, except maybe slightly larger openings (depending on the math) and also located side by side in the center. Also I’ll have a chin spoiler directly beneath them, so, encouraging the air to move into them. One key thing I will make sure of is to not rob air from the radiator, so, they’ll be kept at the very bottom edge of the radiator if not slightly lower. It will all depend on how things line up with the chin spoiler in place. If you look at the front of a 67/68 cougar, you can see this opening mostly already exists as I need it to. It will just take a little modification of the donor valence to make the existing opening a little larger in the center. But the area to place the inlets is already there, almost just as I need it to be.

Yep, that’s pretty much what I have in mind. I’ve been toying with the idea of making an additional second piece to the cowl induction riser that is mounted from inside the engine bay and extends the riser back closer to the window where the pressure is greater, but am not sure about that just yet.

One thing I’ve got in mind also is that if the cowl induction doesn’t seem to really add anything to the ram from under the bumper, I can always put a normal lid on the air cleaner and cut an opening in the hood right near the firewall, to use as an air vent to give the hot air from the engine bay a place to escape when I’m sitting in slow moving traffic on hot days. But I’m hoping it actually plays well with the ram setup and gives the car a little bit more guts at higher speed

8

Here’s a pretty cool web article about aerodynamics which is for sure relevant to alternative air induction methods

http://www.gmecca.com/byorc/dtipsaerodynamics.html

9

Scott here is some more “food for thought”. The article you posted has very good information. Reading the scoop section brought to mind the “Air Box Corvette”. These rare cars (some race ready) I think less than 60 built had a air box. The main reason for the “air box” on the Corvette was to bring in cooler air from outside the engine compartment. The air box would help you achive the positive pressure (however slight) you spoke about in your earlier post.
Steven

Scoops
Scoops, or positive pressure intakes, are useful when high volume air flow is desireable and almost every type of race car makes use of these devices. They work on the principle that the air flow compresses inside an “air box”, when subjected to a constant flow of air. The air box has an opening that permits an adequate volume of air to enter, and the expanding air box itself slows the air flow to increase the pressure inside the box
Air Box on the 1957 Corvette

10

Ah, it’s all becoming clear now.

To get the parts you reaaally want, you might consider scanning craigslist (or posting a wanted ad) for a tailgate mount metal brake like the ones roofers use. You’re going to be using thin enough material that you can use one of those to do all the bends you might need. You can combine a brake, drill, and rivet gun to fabricate a whole lot of stuff you can’t find anywhere, and you can do it on the cheap. I bought a brake for 25 bucks once when a guy caught me the day before payday.
Scrap aluminum or galvanized steel is easy to come by, and learning to bend metal into boxes with the appropriate tabs for fasteners is pretty rudimentary when you start trying to finger it out.

Anyway, you can rig this system up just like Bud Moore did, with basically dryer vent and duct tape.

11

Thanks for the heads up on the brake, sounds like a plan.

I have been planning on galvanized steel sheet for the hood work, and maybe the front valance though there I will probably just bend the existing metal out of my way and not add anything new. Not sure yet.

I already have a welder in my garage, though I don’t know anything about it or about welding at all for that matter. Don’t even know if it’s mig or tig or something else. But I would love to learn, and with my first donor car, I’ll have something to practice on, just to learn, like a too-rotted quarter panel or whatnot.

I’ve done a bit more research and learned some interesting things, including a bit from this website

http://www.vararam.com/ramairinaroadcar.html

They produce a product mostly the same as what I have in mind for the under bumper system, which I need to stop referring to as ram air since from what I read recently, part of “ram air” is the direct path of the air, not going through ductwork. I’m gonna go with “environmentally augmented intake” or something. :slight_smile:

What they had to say mostly confirmed what I already thought, which was nice, but one thing I was shocked to learn is that having a spoiler below the ducts like I’ve been planning is probably bad, that the air being forced into the duct will be more effective if it’s more raw unaffected air, that once air hits the spoiler it becomes more chaotic, less effective at creating additional pressure in the manifold.

I need to read it a few more times, as there’s no way I’ve caught everything they’ve said, and they actually talk about the physics behind the whole process, not just say “our product creates mega boost!!”


Oh and I read a really nice forum thread somewhere where a guy did a sorta scientific DIY test of whether cold air intake systems (like airaid and others) actually give any additional power benefit from the cold air box under the hood, or if it’s really all from the change to the better air filter that the kit uses. My takeaway from all that is that just getting cooler air into the engine can account for a few additional HP, but it’s not a whole lot.

And from what I’ve read, it also seems that nobody credible is claiming that using some kind of forced air induction will create any serious psi boost, seems pretty universal that they agree its very small.

Anyway, so much food for thought out there. I’m gonna have to take a break from researching this for a bit though, I just learned that my task for work for the next week consists almost entirely of searching on google. No way I’m gonna feel like doing that on my own time as well. :bloated:

12

On my < ahem > '89 Crown Vic, I used one of those GT Mustang dual-snorkel air cleaner housings and flexible aluminum dryer / bathroom vent ducting to a point ahead of the radiator support. Not so much for ‘ram air’ but cooler air from outside the engine compartment. Actually, the factory 302/351 setup had a duct doing that on the driver’s side already, so I just had to find a suitable location on the other side considering my engine’s 393 inches and higher-RPM breathing requirements. Worth it? IDK. But what could it hurt?

Spectre Performance has kits with aircleaners with different dual-inlet angles… 180*, 145*, 135*, 120*… and different duct finishes…

From http://www.summitracing.com :

Spectre Performance Musclecar Cold Air Intakes

For all of you who love your musclecar, Spectre musclecar cold air intakes will have you loving your vintage iron even more. Now, you can have the power-increasing technology that race cars and modern cars have employed for some time. Spectre, a company rooted in racing with a definite bias toward early musclecars and speed, has designed simple, universal cold air intake systems for your specific ride. Available for many applications, Spectre musclecar cold air intakes let you choose the location to draw the cold air from–the wheelwells, cowls, front gravel shields, or even the high-beams–with the optional headlight scoops. The more cold air you take in, the more power you make. Spectre cold air intakes help to reduce the incoming air temperature by introducing fresh cold air to the engine for incredible power gains–and since your engine won’t need to work as hard, there’s the added benefit of improved gas mileage. Get back in the groove with the coolest thing available for your muscle–Spectre musclecar cold air intakes.

13

Spectre is a name I’ve been seeing a lot as I do my research. Since I’m looking at doing both cowl and front valance at the same time, that sort of rules out stock components. The dual inlet air cleaners always seem to be totally sealed, designed to seal against a base. Makes sense. But to get the cowl air in, I’m going to need a top that will seal on the underside of the hood. So I’ve been looking at just getting an air cleaner base that either already has two cutouts or that I can cut to make two openings for the valance air, and then I would just need to fabricate a cylinder shaped bit to seal against the base at the bottom and the hood at the top, to get the cowl air in. Depending on the base, if it’s high enough on its own, I might even be able to just use a rubber seal at the top and not have to fabricate a metal cylinder.

Lots of mocking up in my future.

14

Scott maybe my mind is just to small to understand everything that would be happening in the air cleaner with cowl/valance air induction. What’s going to stop the valance ducted air from leaving the air cleaner via the cowl induction area befor it makes it into the carburetor? If both systems are open to the “outside”/leading edge of the air filter element, isn’t it likely that the air coming in via the valance duct would swamp the cowl air and exit the air cleaner assembly via the cowl opening?
Granted I understand that there will still be air available to run the engine. I’m thinking if a anomometer was used to measure the “forced” air from the valance any pressure increase will more than likely drop after the cowl induction is introduced. That is, if you did each system one at a time and took measurements.
Steven

15

My thinking is that since the carb mouth is pulling air in by way of creating vacuum, that the air brought in from the valance would take the path of least resistance and be pulled into the carb, rather than having to fight to push its way out of the cowl where the air is also under pressure.

If it doesn’t work out well, and the valance air is pushing out of the cowl (which I should be able to verify just by taping some ribbons at the rear of the cowl scoop and seeing if they are actually being pushed outward rather than inward) then I can always seal up the opening under the cowl scoop so the carb is only pulling air from the valance, and then cut an opening (or more likely drill several Swiss cheese holes) in the hood right near the back edge, which would then only serve to allow the hot air under the hood to escape, especially when idling, which is something I would be perfectly happy with.

16

Oh and if I don’t use the cowl scoop for induction, it still can buy me a couple inches for a taller air filter, which also seems like a plus.

17

Oooooh, or!!! You could raid an aircraft salvage yard, and pick up a “cowl flap” door! Hinge it, so you can select when you wanted the cowl open or closed! Now you’re talking a “cool” mod!

18

That made me ROFLMAO :spit:

19

Actually, some musclecar back in the day DID have the air cleaner duct to the rear and pull from where our Classic Cat cowl is… Was it Olds or Buick, or…?

20

I know that the Chevrolet Camaro had cowl induction that extended over the cowl fresh air vent.
Steven