I am planning a ram air system for Eileen. Below are some pictures of the concept. What do you think?
http://tinyurl.com/2yz7ql ACAD drawing.
http://tinyurl.com/2259pw The path to the bottom.
http://tinyurl.com/yoasgs Air cleaner bottom
http://tinyurl.com/ywkdgp Air cleaner both top and bottom.
http://tinyurl.com/yw5r28 Another view
http://tinyurl.com/22yle3 Front scoop view
http://tinyurl.com/29e3fx Another front view
http://tinyurl.com/yvnahp Front side view

It rough at this point. I am just looking for your ideas on concept and looks.
It will have a 5" pipe connecting the two pieces. I may also build one large scoop about 3 foot long under the nose just to make it look even. Then just pull air from the one side. Paint it flat black to hide it some. The air cleaner I am thinking heavy gauge sheet metal and have it powder coated red or something. Ohh and the air cleaner will have a strip connecting the top and bottom pieces.
Is there high pressure air where the scoop is? Your ideas welcome.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

Nice design work!

The highest pressure is in the grill and on top of the hood. It's pretty turbulent down low unless you add a spoiler to help direct air into your scoop.

Would you consider putting the battery in the trunk? and picking up the cold
air behind the grill? I put mine just to the right of the radiator and in between the battery.

I can send you a picture if you send me your email.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Nice work. If you use the bottom pick design I would go wider and not as tall with a bck angle on the back of the catcher. Kinda like a flat funnel that has been stretched out to the sides.


What size and kinda of air cleaner is that? I need a drop bottom setup like that.


Ram air does have its advantages, but not as much as you would think. Colder denser is as much of the gain as the added pressure. Coming in through the grill would be good with less clutter. Although it would involve cutting the car picking up the air at the cowl in the two places at the far ends/tops of the firewall would also be a clean setup. Right above where the firewall seems is inthe corners.


No matter how its done it can help with power. In th summer it really becomes important to get the outside air.



Jess

14"
http://www.jegs.com/webapp/wcs/stores/s ... 2_37664_-1

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

From the reading that I've been doing, it looks like the ram air effect is minimal. I will still run the duct down, but the "funnel" will be hidden. It will be more of a 45* angle instead of facing straight forward and looking ugly.
Do you think a single 5" duct is big enough? Bigger would be alot harder.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

You're not going to gain much if any from the ramair..........

But you will gain from the cold air coming in vs the hot air of an open element air filter


You may want to consider a thermostatic system that runs hot air from above the the exhaust manifold during normal cruise operation.

The thermostatic systems are run with manifold vacuum, so when you goto WOT, you get the cold air intake.........

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Yes 5 " would be fine. Try to use smoothwall or even mandral tubing for no turbulance if possible. Its probably not that big deal becuase 5" is plenty big enough so if its not smooth inside it may still flow the air as needed .


Not sure what your meaning on location now but as long as its not in a low pressure area it should be fine.



The ramming effect is not as much as most people would thing, but on the same hand just a little pressure can make pretty good differences in the way the engine breaths. One good way to test the effects on your system is to take vaccum reading in the plenium of the intake itself at WOT, and at high speeds before any changes are made. Then repeat the test as you make changes. Little small things can effect what is happening above and below your carberator.


Thanks for the info onthe air cleaner. I have had some change things going on with a air cleaner here lately. One thing you have ot watch is you need one inch of clearance above the vent tube on your carb between it and the top of your cleaner lid or it will effect metering alot
( dont ask how I know, but its major the effect it has on your carb).


Jess

Jess

http://tinyurl.com/ywkdgp Air cleaner both top and bottom.

Referring to the picture above, the area on the master cylinder side. This section measures 3"x4". (12 square inches) The 5" duct feeding this system has an area of 19.63 square inches. Now I realize some of this air will be used before it needs to pass through this section, but is it big enough? I'd hate to choke it from the start with a bad design.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

The snorkel on my 73 grand prix with a 400cuin engine is 4" diameter, so a 5" diameter hose with a slant should be plenty............

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

If you go with a bottom pickup, beware of standing water! I've heard of a number of folks inadvertently hydro-locking modern cars with low-mounted air intakes by driving into a fairly shallow puddle fast enough to send the spray right into the intake.

I'd look at possibly tapping into the HVAC inlet box below the windshield, near the wiper motor. Yes, it would mean cutting the firewall, but done carefully that's the best place to pick up cool air, plus the highest air pressure point on the car is at the base of the windshield. Of all the Detroit cool air pickup systems over the years, only two ever really showed much ram-air effect. one was the Mopar 6-pack hood scoop on the Super Bee (huge), and the other was Chevy's "cowl induction" that took air from the base of the windshield. An embarrassingly large number of other scoop designs actually *lowered* intake pressure at speed because the center of the hood tends to be a low-pressure area unless you have a tall scoop like the 6-pack.

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5" is more than big enough. 4" would really be plenty.

Yes the ram effect amounts to nothing, it will not likely even overcome the loss of the extra plumbing it takes to get under the bumper. There is allot of turbulence to deal with. You will still see a good increase from the cold air.

The key is to keep the plumbing as short and straight as possible and pickup the best quality air.

I have used low scoops and ended up changing them to behind the bumper or grill systems. I never had trouble with water, but they pick up gravel and all kinds of junk. The shorter, less trick looking systems always worked better, and never ruined the air filter like the bottom feeders.

The cowl is almost always the best spot, but involves cutting that hole in the firewall. Short plumbing, good, clean laminar air flow. It is hard to make a good system that includes hot air for cold weather. I have reservations about making a fume and flame path into the cabin vents as well. I would never consider this with nitrous. It works great on a chevy with a cowl induction hood, but probably not best for a street mopar using the cabin vents.

With what you are already looking at, and to avoid hacking the firewall, I would consider the following: move the battery back or sideways or switch to a smaller one so your hose can go thru the radiator support. Pick up the air between the lower panel and the bumper, or even behind the bumper. The pickup end could just be a 4" or 5" tube 12" or longer with a diagonal cut most of its length with the opening facing forward center. This should shorten the plumbing by about 50% or more, eliminate any water and crushing problems and fit with the air cleaner you already designed. You can always just unhook the hose at the air cleaner and get warmer air for cold weather. Get some good hose, it is expensive.

Remember, no matter how smooth things look, if it is touching the moving air or hanging out there, it is causing drag.

5" is more than big enough. 4" would really be plenty.

Yes the ram effect amounts to nothing, it will not likely even overcome the loss of the extra plumbing it takes to get under the bumper. There is allot of turbulence to deal with. You will still see a good increase from the cold air.

The key is to keep the plumbing as short and straight as possible and pickup the best quality air.

I have used low scoops and ended up changing them to behind the bumper or grill systems. I never had trouble with water, but they pick up gravel and all kinds of junk. The shorter, less trick looking systems always worked better, and never ruined the air filter like the bottom feeders.

The cowl is almost always the best spot, but involves cutting that hole in the firewall. Short plumbing, good, clean laminar air flow. It is hard to make a good system that includes hot air for cold weather. I have reservations about making a fume and flame path into the cabin vents as well. I would never consider this with nitrous. It works great on a chevy with a cowl induction hood, but probably not best for a street mopar using the cabin vents.

With what you are already looking at, and to avoid hacking the firewall, I would consider the following: move the battery back or sideways or switch to a smaller one so your hose can go thru the radiator support. Pick up the air between the lower panel and the bumper, or even behind the bumper. The pickup end could just be a 4" or 5" tube 12" or longer with a diagonal cut most of its length with the opening facing forward center. This should shorten the plumbing by about 50% or more, eliminate any water and crushing problems and fit with the air cleaner you already designed. You can always just unhook the hose at the air cleaner and get warmer air for cold weather. Get some good hose, it is expensive.

Remember, no matter how smooth things look, if it is touching the moving air or hanging out there, it is causing drag.

With the posiblity of designing a system that would be worse instead of better, I decided to do some more research. This research employed the use of a magnehelic and a long hose. The gauge was mounted inside. http://tinyurl.com/39x8sr My finding where interesting. I measured the air at the cowel, center of the hood, grill area, down low below bumper and down just in front of the K-member. All times the measurung tube was facing forward. More test will be done using different directions.

My findings from best to worst.
Just below the front bumper right where I have the ugly cardboard pickup pictured before.
The front grill and cowel are about the same
The center of the hood
Just in front of the K-member. This area produced negetive pressure.

What is interesting is that the best spot yeilded twice the pressure than the next best spot and the worst spot is only a few inches away from the best.
The area just under the bumper starts making pressure around 30 mph and climb fast as speed increases. The other areas start making pressure around 40mph and increase slowly as speed increases. The air at the center middle of the hood is very terbulent.
This was just a quick test and next time I need to bring a pen and paper to take notes to be able to make a graph.
Note: at 50 mph the best pressure peged the gauge.

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67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

That doesn't really surprise me a whole lot. The shape of a car is basically an airfoil and a lot of cars tend to lift at high speed. That's why they put chin spoilers on some cars. The biggest problem with a chin scoop, or spoiler, is that they tend to get damaged in daily driving.

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David Kight
'62 Valiant Signet, White
'98 Dodge Dakota
'06 Jeep Liberty

Growing older is unavoidable but growing up is strictly optional.

It would be interesting to take a reading from inside the air cleaner when you are done. All of those gauges I have seen read both positive and negative, I assume yours does too. Very nice piece of equipment to have available.

The thing about the pressure. The velocity in the air hose will be higher than the speed of the car when you have 300 plus cfm flowing thru there. So a real test would be to check the pressure in the hose at full throttle at different speeds. The pitot tube aimed into the airflow is going to see pressure when you rev the engine even if the car is standing still. The difference between standing still and full speed could then be put to a percentage, but in the end it is all about what the pressure at the filter ends up being.

I don't know how many inches of water your testing showed. But to really put it in perspective you have to compare it to the base line. The base line is one bar or 14.7 psi at sea level. That is what we all have pushing air into our engines. An inch of water = .0360 psi, which is just under .25% of of one bar. It would take 408 inches of water to equal what we already have standing still. Not that much to get exited about, or to overcome drag in hose or elbows for what we are doing.

The reality of drag racing is that we need to get up to speed as much as possible in the first half of the quarter, so pressure at high speed becomes even a smaller percentage when figured against time.

If you look at density verses temp it becomes obvious where the real gains are to be had.

So experience has taught me that it is better to get the air from someplace other than under the car, and if you look at the whole picture your numbers will support this. Even if you somehow break even on the drag in the system, a chronically filthy air filter does no flow like a clean one.

One other thing I have run into. Hot air blown from the radiator fan(s) ends up hitting the ground and coming forward when the car is stopped, like when staging. When moving over hot pavement, the air down there can be 20 degrees hotter than it is a little higher off the ground. This can end up getting sucked into the intake if it is low. I saw this on my Buick by looking back at recorded sensor data. On that car my third and best system was short and had the air filter and intake behind the bumper with no attempt made to get a "ram" effect. The first was a low scoop under the bumper, the second was a scoop behind the grill. It was a learning curve, and it cost me time and money.

I suspect you really want to put the pickup under the car? I am hoping this bit of input might help anyone looking at a project like this.