Wind fairing

[jcfly]

I have an idea to utilize a fairing in a different way. The plan would be to bend or weld aluminum sheet stock to the proper angle, and attach it to the front roof rack via carriage bolts.
My question is this: How much room do you think would be needed between the bottom of the fairing, and the roof of the cab, to allow for the camper to flex without hitting the cab roof?
I'd probably use some sort of foam to fill the gap, and yet be able to do the job without hitting anything.

Anyone care to chime in?

 

[Mark W. Ingalls]

Interesting concept, Jim--

I am wondering about vibration induced from the free end cutting the wind...

 

[Stan@FourWheel]

If you use the "Search Wander the West" feature, I bet you will find some very useful threads to give you ideas. It is helpful to borrow some good ideas from others that have done this already, and then make your own version of it.

Here are some pictures I have saved that might help give you some ideas ...



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[Stan@FourWheel]

more pictures

part 2 ...



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[chnlisle]

Some great ideas there. Thanks Stan but I ask again has anyone doe a with and without fairing milage study?

 

[EdoHart]

Extensive data without a fairing.

Some great ideas there. Thanks Stan but I ask again has anyone doe a with and without fairing milage study?

I have 85 data points for mileage without a fairing on this truck, including average speed between fill ups and notes for driving conditions. Maybe FWC will install a fairing like the one that attaches to the camper on mine. After a few weeks I should have reliable numbers they can use to help sell the fairing as an option.

 

[Stan@FourWheel]

I have only heard feedback from 1 customer so far.

He had an Eagle Model on a 6 cyclinder Ford Ranger truck.

Said that he increased his gas mileage 1 mpg after he added the wind faring.

I did a quick cost estimate awhile back and it seemed like it would take a LONG time to get your money out of it.

If you bought 2 yakima towers, Q-clips, 2 lock cores, 1 cross bar, and the faring, you would be looking at approx. $200.00.

At $ 2.50 a gallon you will have to drive 15,000 - 20,000 miles to get that investment back at a 1 mpg savings (if I did my math right).

If you had a big gap up there, the wind fairing might help a bit more.

They do look nice when done right.


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has anyone done a with and without fairing mileage study?







.

 

[chnlisle]

Stan,
I suspected as much. It seems to me that unless you can get a much more significant savings it just isnt worth the time and effort to install one.

 

[mtndog]

I had such a large gap (~5") between cab and camper which was creating a big air trap, I chose to move the air off to the sides. I found a piece of 4" L-shaped galvanized flashing at the local steel yard, bend to shape, weld on few L-brackets for extra stiffening, installed some t-nuts on bottom side of camper and bolted it on. Easy project for less than $25. Scan Gauge was reading 16.5-17mpg before install, after installation, it's reading 18-19 @ ~65-68mph. The reduced wind noise was well worth it alone, the mileage improvement an added bonus.

 

[jcfly]

Mark: I was thinking of 1/8 inch aluminum, would hope it to be stiff enough to avoid a vibration issue.

Stan: Pictures are truly worth a thousand words, some innovative ideas there.

Ed: Got a picture of your fairing?

Todd: GREAT IDEA - with results to match How much space have you between that fairing and the cab roof?

Maybe, at times, it doesn't seem worth doing. What about gasoline at $4.00 a gallon??? Consider the benefit of extended range as well. In any case, I thank you all for your replies.

 

[fatpete]

Interesting ideas and pictures. I just got back from my first long trip (2300 miles) with camper. I noticed a 2-3 mpg drop with the camper on which seems normal. I think with the right engineering one could develop a fairing that dramatically reduces airflow, costs little, and is relatively simple.
If anyone has more info on mileage with/without the fairing, please post.
On another note, it seems 4WC has increased the height of the front of the closed camper by 2-3 inches over previous models. I'm not sure when they started this, or if it makes any difference to the wind resistance. Anyway, thanks for all the info, this site is great.

 

[davinski]

fatpete:

I have a stock yakima fairing on my dodge 1500 extended cab with hawk with nonextended bed. I have not noticed any difference with or without the fairing with regards to mileage. I do find the camper easier to clean with less bug guts on the front of the camper....Noise is a bit better.

The two side of the camper catch a lot of wind, too. I wonder if a fairing for the two sides of the camper might help, too.

good luck.

dave in seattle

 

[BillM]

I had such a large gap (~5") between cab and camper which was creating a big air trap, I chose to move the air off to the sides. I found a piece of 4" L-shaped galvanized flashing at the local steel yard, bend to shape, weld on few L-brackets for extra stiffening, installed some t-nuts on bottom side of camper and bolted it on. Easy project for less than $25. Scan Gauge was reading 16.5-17mpg before install, after installation, it's reading 18-19 @ ~65-68mph. The reduced wind noise was well worth it alone, the mileage improvement an added bonus.

Hmm, food for thought, I think I'll give this a try on my Eagle. Thanks for the info.

 

[billharr]

Hmm, food for thought, I think I'll give this a try on my Eagle. Thanks for the info.

The picture in your post is the one that inspired me to make mine. Appx 4" PVC fence post cover cut v in back heated and bent. I put a 1/4" Stainless flat bar with a threaded hole in each end and at the V. Bolted from the top.

 

[pvstoy]

Just the fact that it made the wind noise go away and could listen to the radio was worth the cost of the faring. Benifit of not cleaning bugs on the camper behind the cab that is hard to reach is a plus.

 

[John D]

If one looks closely at the Tiger RV, the panel between the base and top resembles a FWC or ATC. The reason is because the same man designed them all. See http://tigermotorhomes.com/

The Tiger Motor Home by Provan incorporates features that probably provide pretty good wind drag reductions, including a close fit between the camper, the roof of the truck, and side fairings which clean up the flat panels on the forward part of the FWC/ATC camper. The corners of the Tiger design are rounded. The man who designed all these campers and RVs is probably the most experienced individual associated with our type of off road camper. The Tiger is a child or brother to our light weight popup off road types with features we could use.

But, let me observe the following about fuel economy; Having driven a truck with a Keystone mounted many miles cross country and having made careful observations on fuel economy numbers, I can say with assurance that speed and weight are the most significant users of fuel.

By carefully driving no faster than 55 miles per hour, a truck loaded with a FWC/ATC popup camper will achieve significantly better fuel economy numbers. For example, on a cross country trip two summers ago in company with another camper from Idaho to Wisconsin we achieved solid 21 mpg numbers, validated by carefully comparing our numbers with the other truck. As soon as the other camper turned south toward his home in Wisconsin, and we went out own way, increasing speed to 60 - 65 mph, the fuel economy immediately decreased to between 18 and 19 mpg. When we became rushed on the last day of the trip and begin to travel at Interstate highway speeds, the fuel economy went down to 14 - 16 mpg. The type of truck here is not a subject because I believe speed and weight are far more important than the type of truck.

Compared to these simple fairings above, speed will be a more important factor in fuel economy. Thus, the key to saving fuel is to SLOW DOWN and use hyper mileage techniques. Never exceed 55 mph. Accelerate gradually. Never accelerate going up hill. Bleed off speed when going up hill. A manual transmission offers significant advantages by permitting the driver to force the engine to remain longer in lower RPM ranges (less than 2000 rpm with a pushrod gasser). The terrain can be used to advantage. Cruise control will cost money over using the "constant pressure" technique of accelerator pedal management.

Driving techniques and speed reduction yield fuel savings that cost little to implement. Combined with fairings, these techniques would probably provide really excellent results. John D

 

[Alex]

I'm with JohnD, speed is the major factor. The faring does help with noise and stability. I mostly cruise around 60mph I've a scangaugeII I can see MPG drop 2-3 if I go up to 65mph. I've Thule roof rack faring.