New FWC camper, wind fairing suggestions

WTW member Kodachrome has a solar panel on his wind deflector

ntsqd nailed it, for rough examples here are some numbers for Cd...

Coefficient of Drag
The aerodynamic "features" of a vehicle in motion are reflected in its drag coefficient values. Low coefficients indicate low air resistance. The following chart list some ranges for various vehicles, which will suffice when actual measured values are not available:

Vehicle Drag Coefficient (cd)
Description Low Medium High
----------------------------------------
Experimental 0.17 0.21 0.23
Sports 0.27 0.31 0.38
Performance 0.32 0.34 0.38
60's Muscle 0.38 0.44 0.50
Sedan 0.34 0.39 0.50
Motorcycle 0.50 0.90 1.00
Truck 0.60 0.90 1.00
Tractor-Trailer 0.60 0.77 1.20


in general, you're not going to be able to do much to create significant reductions on a flat nosed truck and camper package, so yeah, decrease V... (1.2 exists because there are in fact worse C'ds than a brick...)

On August 28, 2015, I tested my highway mileage on perfectly flat roads in Nevada at various speeds: I got 18 miles per gallon at 60 mph fully loaded with my camper, with tires inflated to 45 psi; 17 mpg at 65 mph; 16 mpg at 70 mph; and 15 mpg at 75 mpg. Not bad, considering the truck without the camper was getting 18 mpg at 70 mph. The camper had reduced highway mileage by 4 mpg, before I added a wind deflector.
I attribute an improvement of about 2 mpg after I mounted an Aeroplus wind deflector (available on Amazon) on a Yakima crossbar over the cab in early August 2015, to deflect wind over the camper’s front overhang:

After I added the camper, but before I added the wind deflector, I was getting about 14 mpg at 70 mph, so it’s improved my gas mileage by about 2 mpg, and it does reduce turbulence, so I don’t mind the bat-mobile look. It also keeps the bugs from splattering all over my white camper front, and the wind noise is hardly noticeable. Overall, I’d say the wind deflector was worth the expense (and hassle to modify and mount it, since it’s made only for flat crossbars, not Yakima round ones).

I got a quote from Ballard Sheet metal for $600 for a pair of the 3/8" Aluminum metal deflector 4' X 2' cut to spec like the one in this picture. I wanted to make one that also flips up to protect camper too, when parked in high wind areas of the Columbia Gorge. Does anyone else have this type of fairing? Comments?

ST,

That deflector looks very stout. Is it mounted with a single Yakima bar? Was this a one-off? Two deflectors ["pair"]? Are you planning to mount a second deflector? Wind in the gorge. Some play in it; I avoid it...

Phil

Ps...What does that 3/8" x 4' x 2' aluminum piece weigh?

I dunno.


Sent from my iPhone using Wander The West

About 42 lbs
http://www.onlinemetals.com/calculator.cfm

Paul

I had mine made at Fastsigns for $190 with decal. I mounted it to the Yakima faring hardware.

...I have a complete build of it somewhere on here

Here's my DIY project. I plan to paint or powdercoat the square steel tubing frame.

this thread is fascinating ! Big Steve, that is a great looking fairing... You say it is steel ? I really like the coverage and shape....

Fairing is 1/4" UV-resistance HDPE (King Starboard) sheet, pretty lightweight, flexible and tough. Frame is 1-1/4" x .065 square steel tubing (needs painting or powdercoating). Stiffening stays are 6061 Al alloy angle.

Rockcod said:

this thread is fascinating ! Big Steve, that is a great looking fairing... You say it is steel ? I really like the coverage and shape....

Click to expand...

Any problems with the fairing hitting the cab when the box/camper flexes over uneven terrain? Looks like a very close fit.

It sometimes bumps the roof on rough terrain. It's a bit noisy but no damage because HDPE is soft and flexible. I plan to do a bit of trimming. I have pondered installing some sort of rubber bumper or door sweep, although that would require a mechanical connection because glue doesn't stick to super slipper HDPE.

Vic Harder said:

Any problems with the fairing hitting the cab when the box/camper flexes over uneven terrain? Looks like a very close fit.

Click to expand...

Big Steve said:

It sometimes bumps the roof on rough terrain. It's a bit noisy but no damage because HDPE is soft and flexible. I plan to do a bit of trimming. I have pondered installing some sort of rubber bumper or door sweep, although that would require a mechanical connection because glue doesn't stick to super slipper HDPE.

Click to expand...

HPDE... otherwise known as teflon?

Vic Harder said:

HPDE... otherwise known as teflon?

Click to expand...

You switched a couple letters there. HDPE = high density polyethylene.

FWIW, Teflon is polytetrafluoroethylene (PTFE). GoreTex is expanded polytetrafluoroethylene (ePTFE).

I used the Yakima Q Towers and fairing.Worked great. I have an extra bar, two Q Towers, and locks. All of its new. The only thing you would have to buy is the fairing and a set of Q clips. I will let them go for $150.00. Give me a call if your interested. Bill (719)659-6144.

I have an extra bar and fairing from an old bike rack system that I might install, but one thing that concerns me about the effectiveness of roof fairings to reduce drag is that there is a also a lot of flat surface area on the front wall of the camper that is exposed to the wind, not just the thin roof. I have an F250 and the shape of the cab still leaves a portion of the sides of the front camper wall in the direct path of wind. I would estimate at least 6 square feet, which is about the same as the roof portion. I read somewhere (and this could be wrong) that it takes 5 horsepower to push a license plate through the air at 65mph. If the exposed frontal surface of the camper is about 12 square feet, that's about 60 hp needed at 65mph. I know when I drive in a strong headwind I go from about 14mpg down to 10-11 if I maintain my speed-the truck has the power (tuned diesel) but I pay!

Anybody have any links to real-world data on how these types of fairings perform?

Steve, what is your source for the HDPE? Looks like Home Depot has it, but only in smaller sheets (up to 48" and looks like yours is considerably wider than 48").

Thanks,

My thought on my Tundra with Hawk is to use a a pair of maxtrax as the fairing - mounting this to a yakima or similar roof top tower bar system, as soon as i can find one on craigslist. This should kill two birds with one stone - a place to store maxtrax and a slightly quieter ride. Not counting on much mpg savings as the Tundra's 5.7L V8 is a gas guzzling beast.