Wind Deflector

[MikeJinCO]

I'm going to put a wind deflector on the truck overhang of our Host Mammoth. Does anyone know if it is a Azdel of luan panel? Do I need to predrill the fiberglass oversize to prevent the fiberglass panel cracking? I'm using panels of fiberglass about 1/8" thick that I laid up as not a lot of plastic sheeting is available around here.

[MORSNOW]

HMS Beagle wrote:
I've got the valence, built and painted the mount, and have the 3M VHB to attach it. All that remains is sticking it to the camper. That requires at least two on/off cycles which I will get to in the next couple of weeks.

There is some question as to where the ideal position would be. It would be nice to be able to trial it at several positions before mounting permanently. I'm guessing about even with the top of the window glass or slightly behind that.

Sweet! Looking forward to hearing about your results, both good and bad.

[HMS_Beagle]

I've got the valence, built and painted the mount, and have the 3M VHB to attach it. All that remains is sticking it to the camper. That requires at least two on/off cycles which I will get to in the next couple of weeks.

There is some question as to where the ideal position would be. It would be nice to be able to trial it at several positions before mounting permanently. I'm guessing about even with the top of the window glass or slightly behind that.

[MikeJinCO]

Beagle- look at the 3M double sided tape used to hold solar panels on available at the hardware in several strengths. Have mine done, just need to get to warmer weather to put it on as camper has to come off. If it quiets down the buffeting I'll call it a great success.

[mountainkowboy]

It had to be 15 years ago when we went through the same motions. There were many designs that were tried, and this is what we found.

The "air foils" did nothing for fuel mileage. Some improved aerodynamics and had less buffeting. Most kept the underside of the bed cleaner of bug guts. I tried a "V" design similar to the one in the pic. It did keep the under cab bend much cleaner of road grime, but increased buffeting on our supercab with the windows down. So it was removed.

[Bedlam]

bighatnohorse wrote:
On a 1000+ mile trip I picked up 1.5 mpg simply because of a slight tail wind.
It only take a mild 5 mph wind (head or tail) to make a difference.

I always get better mileage going east than west due to the trade winds. It hasn't been enough difference to circumnavigate only in one direction.

[HMS_Beagle]

I'm about half way through the build on mine. I bought a bumper valance (replacement for stock) for a 4wd truck same year and model (2015 F350). The 2wd version is 4" tall, the 4wd version is 7" tall. Decided to make a fiberglass plate with blind nuts to mount it, that way it is easily removable/replaceable for maintenance or testing. This will be stuck to the camper overhang with VHB or PU (no holes). The styling dept. at Ford made the valance match the width and approximate curvature of the truck cab so it doesn't look too bad. It is plastic so incidental contact with the cab will not be catastrophic. It was cheap and seems durable. Only question now is how far forward/back to mount it. It would be great to be able to experiment with that but I've got no ideas how to hold it in place temporarily to try.

I'll post some pictures when I get it done.

[bighatnohorse]

Hemi Joel wrote:
I was on a road trip and picked up a hood for one of my project cars. I had no place to haul it except strapped to the roof of the truck. I was surprised to find that it picked up almost 1 mpg on the 900 miles home. I'm going to build a deflector, probably like Sleepy did.

On a 1000+ mile trip I picked up 1.5 mpg simply because of a slight tail wind.
It only take a mild 5 mph wind (head or tail) to make a difference.

[Hemi_Joel]

I was on a road trip and picked up a hood for one of my project cars. I had no place to haul it except strapped to the roof of the truck. I was surprised to find that it picked up almost 1 mpg on the 900 miles home. I'm going to build a deflector, probably like Sleepy did.

[billyg]

Hi it's been a while since I responded to something here is my 2 cents. I actually installed an inverted bug deflector made by stampede that goes on a 1999 chevy suburban. It works great for me. Bill

[ticki2]

Sleepy’s airfoil project is the TCU under camper exterior

[JimK-NY]

I usually open both the rear truck window and the connecting window from the camper. I have a foam "donut" to seal the gap. If the seal is not good I get whistling noises. The donut is essential. Without it the dead space is gone and I would not be surprised to have wind buffeting sounds and bugs/water/dirt enter the space and even go into the camper.

Anyway before attaching a deflector to the truck or the camper, I would try some experiments. Seal the gap between the cab and camper with foam or perhaps with a canvas dropcloth and see if that helps anything.

[kohldad]

I was fighting a water leak at the pass through window when I switched from a 2004 Dodge to a 2015 Ram where I had to raise the camper 3/4". Ended up putting a deflector across the middle of the cab over because I was able to use 4 existing holes in the sheet metal. It reduced the air pressure and changed the direction of the wind enough so the leak was stopped. The added benefit was it reduced the bug count at the top of the front wall under the cab over. It actually added a bit of wind noise in the cab and I didn't notice any change in fuel mileage.

If I was to add one to a fiberglass camper, I would make sure it is angled fore/aft and just use a strong double sided tape. One advantage to this is if you decide it doesn't do what you want, you can remove it without any damage occurring. Plus screw holes equals leak, especially in what will be a high pressure water driven area.

[HMS_Beagle]

It isn't really the camper directly behind the cab. I get splatters to the sides of the cab on the part that sticks out, and platters all the way across in a few inch band just below the overhang - where the 90 angle is. If I open the back window it is very different, camper/no camper. There is also more/different buffeting with the windows open, and more wind noise generally.

It isn't a surprise to me that different truck/camper combinations are different. There are many variables in shape, gap, height, overhang, shape of camper nose.

[JimK-NY]

HMS Beagle wrote:

I have quite a harvest of bugs mainly on the outside edges of the camper but extending in and even all the way across up high (over the cab). There is also a nice pattern of bugs under the overhang somewhat defining the shape of the cab. There is definitely more wind noise with the camper on that with it off.

I wonder why there is such a difference. I have had two trucks and have traveled with the camper for close to 100,000 miles. The camper behind the cab never has any bug splatters. I can drive through heavy rain and it will usually be dry behind the cab. The exception is when I am parked and the water blows in from the sides. There seems to be a cushion of air not only behind the cab but extending forward between the camper and the cab. That is why I conclude that an air deflector is not going to accomplish anything. At least that would seem to be the case for my camper.

The area between the camper and truck bed is also a dead zone. I have access through doors on both sides and I use that area for storage such as extra clothing, paper goods, a long extension cord and a tarp. Everything is always dry and clean in that area.