So I have been wanting to add a front air dam to my E250 to see if it will help my MPG. Finally decided it was time. I had a bunch of scrap stuff left over from other projects, so I started mocking stuff up.
There are already holes on the underside of the bumper to put bolt through, but I had to figure out how I would attach it.


I ended up fashioning a few brackets with a combination of some 90* shelving type brackets and perforated angle. Each one is held in place by 2 5/16" bolts.


I then attached the brackets to a piece of plywood that I cut to simulate the front part of the air dam.


Attached it to the van to get an idea of how it will look. I am still working on pieces for the corners so it follows the contour of the bumper.



So far so good. Hoping to have the mock up all done tomorrow, then I can use it as a model for the actual unit. Still debating on what hardware to use on the final piece. Stainless will be used to bolt the dam to the brackets, but I am not sure about attaching it to the bumper. Stainless won't rust, but it isn't exceptionally strong. A hardened bolt could work, but it could rust and I know hardened fasteners (class 8) can shear with sideways force while regular fasteners (class 5) will bend instead. Also wondering if 5/16" is strong enough or if I should go bigger. What do you think?

 

I Have a Mint Condition Fibreglass one aproxx 5" you can have for free...You pay for the Ride..
PM me if interested...
As far as answering your Question goes ..The smaller size is fine...I would attach another "L" type piece on each end ....To achieve what you want....

 

Thanks for the offer. Depending on how this one turns out I may take you up on the offer. 5" may not be enough though, I was trying to get low enough to be even with the bottom of the rear diff cover......and I was kind of bored so I found a project.

 

Just a thought, if you could find an appropriate style of vinyl flooring, could you attach that to your wood base and create the contours you need?
I once had the fiberglass one on a '78 E250. It's a slick looking piece. Be interesting to know if this improves MPG's.

 

I don't want to bash anyone's effort trying to increase MPG's but expanding your frontal area probably won't do much. I dare say your present configuration would act like a snow plow. Most every factory van has at best a very small "scoop" to channel air flow from under the bumper upwards to the radiator but they're very very small in area.

Aftermarket front dams are/were available either separately or on conversion vans but they were more for appearance than anything really functional. Well, some of them did house lower mounted driving lights so not totally useless!

Without addressing the issue of relatively high ground clearance on the sides a front dam or spoiler will be for looks only. It was once suggested here by another user something like "belly pans" might make a difference all by themselves but so far no one has ever tested that concept.

The sad fact of our vans is as far as aerodynamics we're dealing with oxymorons!

Definitely keep us updated if you notice anything different.

 

I can adjust the angle of it, so I may mess with that while in the testing phase to make it less flat. In theory, pushing the air to the side with the air dam takes less energy than overcoming the drag caused by the uneven underside. With that in mind a belly pan would do this without increasing the frontal area....but I didn't want to mess with that.

I will keep everyone updated on my progress and results.

 

No JayRo its a tough project whatever way you approach this.

I hope it does yield some positive results----I'll have a NASCAR lookin' thing installed in no time so!

While you're adjusting things angle it from the center of it back towards the wheels on each side. That would help push the air outwards.

 

Working on the air dam some more.


Got the corner pieces attached so it contours with the bumper


Then since I was sealing up some of the guttering that had rotted away with caulk (supposedly it dries clear)


I went ahead and filled in the joints on the air dam


Next step, after the caulk dries, will be to paint the air dam with some left over black paint I have. Then I will test it for a few weeks to see if it helps and maybe make some more design tweaks. If it helps then I will make a more finished/non-wood one.

 

Is that a builder's caulk, something used around the house?


That's taking shape just fine, contouring the very ends close to the tires is a great idea.

 

Its acrylic caulk. The stuff used for window, doors etc. A friend of mine runs a body shop (Welcome to Grabill Automotive) and suggested I use it for a temporary fix until I can make it permanent. This way I won't have water running down the back door when it rains and getting the carpet wet etc.

 

Threw a coat of flat black on it. You can see from the pics that its not quite dry yet. Going to have to take it off to reach the edges and the back.

 

Okay---that's good advice on your buddy's part then---keep it dry 'til later!

I'd suggest for that gutter fix one of 3M's products, either #08300 or #08405. As with all 3M stuff they're both better than excellent!

 

I will have to check that out. The rest of the gutters are great. Just the one area where water got behind the sealer and rusted through.

 

I did build an air dam for my van a few years ago. I used a piece of 16 guage angle speel. The type that comes with multiple holes in it already. It's what I had so that's what I used. I then purchased an 8 ft length of PVC house trim. It came with wood grain on one side and smooth on the other. It was 5 1/2 inches wide and 3/8 thick. I cut it to length and then drilled holes and pop riveted it to the angle steel, which I then bolted to the bottom of the bumper. To contour the ends of the PVC I used a heat gun that softened the PVC and I was able to bend it to a smooth curve.
Since it only comes in white I painted it black to look better with my gray van.

It's not as deep as yours but it did make a difference. On windy days the van stays in my lane and I don't have to saw at the steering wheel to keep it in one lane. As far as MPG changes I can't really say. Since I only get 10-11 mpg when I use the van (Towing my race car) a change of 1/2 mile to the MPG is not really going to be noticed. A strong head wind will eat up 1-2 MPG's so it's hard to track mileage and compare.

 

Do you have a picture of it? I also have a leftover sheet of sheet metal in my garage. I forget the gauge, but it is fairly thick (thicker than normal AC ducting). I was thinking about taking it and just bending it to fit over the plywood. May not be the best solution, but it would get rid of my scrap stuff and cost me nothing out of pocket to do.

Also, what kind track car do you have? I use my van as a tow vehicle for my track car as well. Works great, I can tow to the track and then camp out in the van which has a bed in the back. I have a '94 Taurus SHO that I set up for a road course car.