Yet another Air Dam/Spoiler/Airfoil thingy

[HMS_Beagle]

Since we don't have enough threads on this already:

I decided to make one, the goal was to reduce wind noise which was more with the camper on than off. Also wanted to reduce the bug count on the camper bulkhead.

I saw some posting in which a guy used a valence (front air dam) for a truck, looked pretty good so I stole the idea. I used the valence for my truck and year model, figuring that it would be the width of the cab. This comes in two versions, a 2WD model about 5" high and a 4WD model about 7" high. It looked like I had room for the 7" so I ordered one (and aftermarket one) for about $110. To attach it, I cut a piece of fiberglass G10 plate, 1/4" thick, to match the valence shape. I CNC cut some recesses in the top side to accept blind nuts, then used 3M VHB to stick it to the camper overhang. The molding was a little floppy and distorted, perhaps because it was aftermarket, though it is about as thick as the one under my truck.

Here is the mount stuck to the camper. I set the tape slightly in from the edge and then caulked the edge with 3M 4000UV to protect the tape:



* Adjusted image size using width=640

[HMS_Beagle]

Another update on mine. Stiffening the lip eliminated the folding back. For the last trip (only 350 miles but in bug country) I cleaned the camper bulkhead and overhang. No bugs on the bulkhead except right outboard. No bugs on the overhang except in a pattern near the edges of the valence. Still haven't noticed a marked difference in mileage, headwind/tailwind makes far more difference than anything. I think the noise reduction is real.

[MikeJinCO]

Took the camper off yesterday. NO BUGS first time ever.

[MikeJinCO]

This is always an interesting experiment and with the current price of fuel important. I added my deflector last November that was made from fiberglass panels around Sleepy's ideas. We did not notice a noise reduction, but then I have read that one has a very short memory span for noise, and our firsts trips were around Phoenix rather than on the highway. Last weekend I got in a fuel test going from home at 8300' over two low passes and down to about 5000' east of Denver and then back. A trip of about 160 miles each way. I had the cruise set at 60mph both ways and of course take it off climbing the passes. Result was 13.3mpg as compared to my long term typical 11.7 at an normal 62mph. I regard that as a great change. Rig ismy 2006 Duramax with monstrous Host Mammoth.

[notsobigjoe]

https://www.truckcampermagazine.com/camper-mods/contests/aerofoil-wind-deflector/

[HMS_Beagle]

Update:

I added a stiffener to the lip of the valence, 1/4 x 3/4 aluminum fit behind the molded lip nicely, just bent it to shape screwed through to some tapped holes.

Second 900 mile trip from home to Anacortes, WA, about 900 miles, this time with the wife. She immediately noticed the reduction in wind noise. The valence held its shape. From the rain pattern, it seems to be different when it stays in shape. The camper bulkhead is dry, even in fairly heavy rain. There is an arc of wet about 12 - 18" behind the valence on the overhang, this seems to be where the jet of air squeezes between the windshield and the valence. The V of water from there back where the valence folded is gone. I should have cleaned the bugs from the bulkhead before I started this trip, can't tell if that is different because the old bugs are still there.

Fuel mileage last trip was reported as 12.0 mpg last time, 13.8 mpg this time, but I think most or all of that can be accounted for by better weather conditions. Last time persistent headwinds, sometimes quite strong, this time more even handed and not all that strong. I don't think mileage has been affected significantly either way.

[HMS_Beagle]

Wtih anything between overhang and cab, you must be very careful. The cab roof isn't very strong and even soft foam at a couple of PSI might well cave it in (2 PSI on a cab roof 4'x6' is about 3 1/2 tons).

[JimK-NY]

I am not sure if an insulating pad between the cab and camper would do much. In addition to the built in insulation, I sleep on 8" of a highly insulating foam mattress.

If cold is an issue, I have found two really significant improvements. I improved the gaskets on camper door and hung a curtain not above it. A heavy blackout curtain does wonders for privacy and to retain heat and stop the drafts. Indoor/outdoor carpeting on the floor made a huge difference. I thought it would be too difficult to keep clean but that has not been an issue. Next I put rigid foam insulation between the rails of the truck bed and the camper. That sealed the base between the truck and the base area of the camper. Any or all of these would be easier than trying to insulate over the truck cab area.

[Johnnybgood]

I have thought of doing something like this for our Host Cascade. But instead of just a valence it would have an insulating pad that fits in between the camper and cab to help with the temp in the bed area. We to have a line of bugs at the bulkhead.

[HMS_Beagle]

Well I think the first fix will be to stiffen it to prevent the distortion. It is quite stiff out towards the ends, but pretty floppy in the middle.

Hard to know what holes will do, where to put them, how big, how many. I note that some previous efforts feature holes. But I don't know of any comparisons with and without.

[notsobigjoe]

Beagle, Perhaps a series of different size holes in the center and moving out to the side. Large to small to let some of the air through as to prevent the deformation?

[Reisender]

Looks kinda funky. I like it from the aesthetics point of view.

Cheers.

[HMS_Beagle]

I almost never drive with the side window open. I used to have a boot for the cat crawl through, and left the rear window open, either way it made no difference on the bug pattern.

[JimK-NY]

HMS Beagle wrote:


Bottom of the overhang will be wet and is spattered with bugs. There is a line of bugs on the camper bulkhead and it will be wet in the rain. Opening the rear window resulted in a large wind through the cab. Air flow in the area is much different after installing the dam.
....

I have always had a boot sealing the space between the rear cab window and the pass through in the front of the camper. Perhaps driving without a boot and leaving one or more of these windows open might break the dead air pocket and allow water and a splatter of bugs to hit the bulkhead of the camper.

[BigfootBill]

I wonder how a bug deflector on the front of the hood would change the airflow. May be something else worth considering.