72 replies to this topic

[ski3pin]

WTW member Kodachrome has a solar panel on his wind deflector

[broncotime]

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...)

Edited by broncotime, 11 January 2016 - 11:56 PM.

[amosclyde]

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).

[Stromtrooper]

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? 

Attached Thumbnails

• 

[Wallowa]

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?

Edited by Wallowa, 15 February 2016 - 06:43 PM.

[Stromtrooper]

I dunno.


Sent from my iPhone using Wander The West

[PaulT]

About 42 lbs
http://www.onlinemet.../calculator.cfm

Paul

[100acrehuphalump]

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

Attached Thumbnails

• 

[100acrehuphalump]

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

Attached Thumbnails

• 

[Big Steve]

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

 

 

 

Edited by Big Steve, 21 March 2017 - 07:04 PM.