11 replies to this topic

[brett13]

Inspired others, especially the aluminum one, I embarked on making yet another one. My first two attempts involved specially ordered plexi. Don't waste your time with plexi, it won't hold up.

Since I don't know much about aluminum, I went the easy route: plywood. Half inch. Bent some aluminum pole clamps and made some supports, primed and painted. Then mounted on a yakima crossbar. Here is the result:

[brett13]

Maybe you can see it better here, though in this pic it looks like it is in front of the glass and it's not, that's just a shadow:


How does it work? Amazingly well. Wind noise is cut down and that vacuum/sucking effect when you pass a truck going the other way is gone. So is the buffeting when you are just the right distance behind a big rig. Not sure if it improved mileage, but it didn't hurt. I'm guessing it must have improved a bit.

Two flaws though. The yakima doesn't have a strong enough grip to prevent the wind from pushing the fairing back until it hits the camper. That's where the block and duck tape came in- to add a spacer. Unfortunately, that ended up squeaking like crazy against the little rubber/plastic camper trim after every bump. Good news is that this sliding didn't happen constantly- only when total wind got up around 90. By that I mean forward land speed plus gust into our face. There must be a way to make the yak bar hold tighter. Time to experiment.

The other flaw is that I built it so that the mount is in the middle of the 45* angle. When the wind hit it, it can rotate the fairing on the axis of the bar so that it hits the camper and has a few inches between the bottom edge and the roof. I fixed this by building a little footing at the back edge that touches the roof. Works perfectly, but it isn't pretty.

[Overland Hadley]

Thanks for sharing your experience.

I am still trying to decide how I am going to do mine.

[chnlisle]

I've been watching these post with a lot of interest. Now that it looks like fuel prices are never going to go down I have an even greater interest. I understand that wind deflectors divert bugs away from the camper but I don't' have a lot of difficulty washing the dead critters off when I get home from a trip. Some here say the wind noise is greatly diminished with the deflector but here again this doesn't seem to be a problem for Pam or me. I've scoured the internet and see tons of listings on how these things save on fuel but can't find any test results or actual figures (except for long haul semi trucks) on fuel savings. Further, it seems to me that sticking a sail up into the air flow might take even more fuel to overcome the drag. Since I'm often wrong on many things...... would someone here please produce some real data on fuel savings.

[brett13]

I've been watching these post with a lot of interest. Now that it looks like fuel prices are never going to go down I have an even greater interest. I understand that wind deflectors divert bugs away from the camper but I don't' have a lot of difficulty washing the dead critters off when I get home from a trip. Some here say the wind noise is greatly diminished with the deflector but here again this doesn't seem to be a problem for Pam or me. I've scoured the internet and see tons of listings on how these things save on fuel but can't find any test results or actual figures (except for long haul semi trucks) on fuel savings. Further, it seems to me that sticking a sail up into the air flow might take even more fuel to overcome the drag. Since I'm often wrong on many things...... would someone here please produce some real data on fuel savings.

Eyeballing from the 1500 miles I've had with the fairing, I see little to no difference in mpg. Certainly not worse, but measurable improvement is within a margin of error so far. For me, the plusses were 1) reduced 'vacuum' effect when passing trucks and vehicles in the oncoming lane and 2) reduced wind noise. A big checkmark on both accounts. The hoped for mpg improvement has yet to be felt.

I wonder if the vaccum effect is worse on a half ton? Less mass and stiffness in the chassis being the cause. Just a guess.

[ski3pin]

I'm kind of with chnlisle on this one and thanks Brett13 for your response. I like to build and design things and this has been a project I've had on the list. But I'm old enough to know I want to only tackle the necessary projects.

Our older camper sits low over the cab with only a small space between the top of the cab and the bottom of the cabover. Also our cabover is a little narrower than some newer campers. We do not get much wind noise - as least that we find in any way annoying - and don't get knocked around much by passing semis.

On this one I'm going to go with the "If it ain't broke................" even as much as I'd like to build one!

[chnlisle]

I'm kind of with chnlisle on this one and thanks Brett13 for your response. I like to build and design things and this has been a project I've had on the list. But I'm old enough to know I want to only tackle the necessary projects.

Our older camper sits low over the cap with only a small space between the top of the cab and the bottom of the cabover. Also our cabover is a little narrower than some newer campers. We do not get much wind noise - as least that we find in any way annoying - and don't get knocked around much by passing semis.

On this one I'm going to go with the "If it ain't broke................" even as much as I'd like to build one!

I've decided to ad a couple of exterior 12V outlets instead.

[highz]

I think we all realize that the easiest way to save on gas by lowering drag is to drive slower. I don't have plans to add a fairing unless I find myself having to travel on the intestates more often (doubt that will happen). In that case, the fairing would be to reduce noise in the cab, not improve fuel efficiency.

[Mark W. Ingalls]

My prototype reduced the wind noise coming from my roof rack enormously, which causes me to drive faster unless i pay close attention to the speedo. Probably end up hurting my mileage 'til I recalibrate my auditory speed sensor...

[brett13]

unless I find myself having to travel on the intestates more often...

That's my issue- lots 'o highway time.