Please Trash my Cheap Air Dam Idea
 

My Dodge Ram's factory air dam doesn't go down far enough to prevent air from impacting the front suspension, or the other rough areas near the engine.

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For aero mods to be cost effective they must be inexpensive. What I'm thinking about is getting a second factory air dam, inverting it, and attaching it below the existing one.

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This should be fairly cheap, $50-$100. The extra 4" in depth should help aero, but shouldn't interfere with normal operation.

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Since there is a nice flat surface around the bottom of the existing air dam attaching the second, bottom to bottom, should be easy. Maybe 7 bolts.

Also the flat upper mating surface, what will be the bottom on the new one, should make it easy to fill that area with a sheet of 1/4 ply. Will be about 16" back from the from edge.

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Since I'm pretty new at this, and need to learn, please fire away. Tell me where I'm right, where I'm wrong, just plain nuts, and improvement ideas.

$50 for an air dam is WAY TOO MUCH! You would be much cheaper off to use landscape edging or something similar, which can often be had for under $2/ft.

clearance
 

Drive around to places you normally go,which require you to nose up over a raised curb/sidewalk in order to park.Measure your free space vertical clearance up to the existing airdam.
This will give you an idea if you're fixin' to shear off the lower dam or not.
It really sucks when that happens!

sounds good to me. you might need a way to brace it so the wind doesn't make it collapse backwards at speed.

Aerohead, raised curbs are a rarity to me. This is an advantage of living/working in smaller communities.

Bill, since the curve shape of the existing dam holds well at highway speeds, with the current mounting, I'm hoping it will do the same when doubled. Plus I'm going to do 1/4 ply mounted just above the bottom. This should keep the airflow away from the suspension, plus stiffen the structure.

Thanks for the input.

Well, nobody's called me a horse's rear yet, so maybe I'm onto something good.

I used some extra roofing sheet which is a flexible rubber about 3/16ths of an inch thick. I went down 4" to match the suspension components on my Dakota. I then helped support it with a little bit of sheet metal, but I really need to redesign that.

I did all that, along with Royal Purple Gear oil in the rear, and full synthetic change of the transmission... and then started going to a different job so i wasn't able to properly test a difference in economy. I don't think it was a huge difference though... sadly.

Also, instead of using 1/4" ply for your bellyban stuff, coro-plast, or the plastic cardboard stuff that signs are made of, would be a LOT better. Lighter and just as strong.

Also, think about a grill block. I plan on doing that next and see if it works any better since when the weather bumped up, I went from 14 to 17 mpg with no change other than getting a few extra tools out of the back.

I know everybody here really likes coroplast. But I've got some spare 1/4 (along with 3/8, 1/2, & 3/4) ply in the tool shed. So it's got the edge.

And it's a BIG no on grille block. I spent 10 grand and 3 months (don't ask!) getting this trucks motor replace a year ago. Water pump went bad and heat destroyed the motor. The 4.7 doesn't like heat. So anything that maybe possibly could someday interfere with cooling is out.

The reasons for using a factory air dam: 1) ease of install, no engineering required. 2) will look like a factory job, air splitter will be hidden.

If you've got it, use it. It's going to weigh a bit more than the plastic, but probably hold up a bit better if you make sure to put a good coat of paint on it to prevent water damage. Overall the extra weight probably won't make a dent in the MPG's as it's only a few pounds.

The reason Bill in Houston mentioned bracing it a bit more is because of the added wind load on the air dam. It may not be a problem, but the last thing you want is the existing dam cracking due to the pressure. A $2 bracket or two is far better than the $50-$100 air dam.

I have the 4.7, I"ll let you know how it does with a grill block.

X2

Cool idea if you can do it cheaply. It is amazing what those things catch on. I have cracked or broken several airdams over the years. Since you are starting with a high clearance vehicle, maybe you'll be OK.

Check out the Corvette OEM solution for a lower aero clearance but still have ramp clearance. An underside lower spoiler mounted deeper inboard from the very front. It diverts air from going under but still allows a deep entry ramp angle.

Looks exactly like garden edging!

http://www.seriouswheels.com/pics-20...e-1280x960.jpg

The closer the dam gets to the front axle line, the lower it can go before hitting stuff. But I'd imagine it doesn't work at all if it's aft enough to be behind the front edge of the front tires.

Seems like the farther back it goes, the more it looks like a rough underside rather than an airdam. Still, you could make a really low one right back where that one is and test it out.

I'm struggling with this myself on the CR-V. The nose is very tapered, and there isn't the same kind of obvious place for an airdam like there is on most vehicles. The farthest-forward reasonable mounting point is just barely ahead of the front edge of the front tires.

There are times when a smooth bellypan is a better solution than an airdam. That is the direction I went with the Golf. The factory bumper scrapes often enough as it is.

Thanks COcyclist, for that advice. That is what I am thinking, too. I think I will go with a bellypan, and not an airdam. Everyone be on the lookout and please chime in when I get started on the bellypan. Hijack over.

Bill, if you were truly trying to hijack the thread, you would have yelled "Eco Akbar!!" first. I think that's in the rules somewhere.......

hi my first post . Q has any one used stiff brush material as an air dam material not 100% block but should be forgiving what do ya think

There was a long debate on mesh screen as a grill block on here that would probably be relevant. I assume you want to use this because you happen to already have some? Or maybe for flexibility? I think more solid materials would be better, probably.

From what I understand, smoother is better. Brushes are anything but smooth.

I'd recommend a belly pan and a custom aerodynamic topper. It can be made of plywood or coroplast if you like. Should go down at about a 15* angle.

http://www.evworld.com/images/pknox_toyota.jpg

Of course if you often haul tall loads that won't work too well.

When you make the belly pan, pull it straight forward, and wherever it ends up is how far down the air dam should be. Does that make sense?

Mine was around $16 http://ecomodder.com/forum/showthrea...dam-18663.html

That ITB air scoop shouldn't be any bigger than it needs to be - any larger you just make drag and not 350hp might need 4"-4.5" of intake area? Maybe I'm over estimating that even.

Picking up air from the centre of the front bumper would be the way to go IMHO, that's the single place on your car where the air pressure is highest. This is also where it would produce almost no increase in drag, in fact I don't see how it would increase drag sucking up air from a high pressure zone.

Don't know too much about these things, but I would have thought ITBs sucking free air isn't as good as a properly sized/tuned plenum, you can then run an intake pipe to pick up a nice ram-air effect from your bumper.