Succesfull fule mileage increase with Snow board wind deflec

[printer]

In the test with the car/spoiler, you would want the spoiler to be at a higher angle, like 45%. In your picture its almost flat.

Yes I did it at about 45 degrees on the last run. Those were from earlier runs. I had to make the spoiler touching the trailer otherwise the positive pressure of the trailer gets sucked under the trailer. I guess I could make it bigger but I still wanted to be able to see out the back window.

[Socal Tom]

You could put the spoiler above the rear window, ( on the roof) and see how that goes.

FWIW, this is how my rig worked out.

[tony.latham]

One problem with these online wind tunnels is they are 2D and our vehicles and teardrops have that damn third dimension.



I noticed a significant difference when I bumped from a 4' wide teardrop to a 5' a decade ago.

Tony

[printer]

One problem with these online wind tunnels is they are 2D and our vehicles and teardrops have that damn third dimension.


I noticed a significant difference when I bumped from a 4' wide teardrop to a 5' a decade ago.

Tony

Yes, take the information it gives you with a grain of salt on how much it applies to you. But I would not have thought the air from my car would go under the trailer and the outline with the 'skateboard' on a SUV type vehicle does what the video says but a spoiler does not seem to help a sedan. I was going to make a model of my car and a trailer, make a little wind tunnel, use smoke to see what happens. But this is much faster. My main question was whether a teardrop type is much more different in wind loading as a square back. I got my answer and more in a couple of hours trying different arrangements. I would not use it to do minimal changes trying to get a best performer, but as a sanity check it is not so bad.

[Modstock]

You could put the spoiler above the rear window, ( on the roof) and see how that goes.

FWIW, this is how my rig worked out.

I was thinking the same thing, might help his car out.

Remember a few years ago NASCAR put a "wicker bill" on thier rear spoiler.
Basically its a piece of aluminum angle iron, L-bracket accross the fin.
It didnt help the cars much but it did help drafting and 2 cars could go way faster. Punched a bigger hole in the air , as they say.
I wonder if this could help towing a trailer ???

Always wondered what those
"air tabs" would do mounted accrossed a rear spoiler/wing .

I ponder way too much car stuff .


Sent from my SM-A115AP using Tapatalk

[gudmund]

with the roof rack I see on top of your vehicle in the picture here, I see an 'angled edged' roof panel mounted on the front the rack being used = I would be trying a larger angled piece of material, making it long enough - exstending it down for contacting to the vehicle roof. This could help 'in kicking' the air "up" from the hood/windshield area "up and over" thus maybe getting it to travel higher so as to clear the trailer as it travels over everything. (a piece of plywood or something may work for a test of this )
Air tabs = 'vortex generators' I have looked at them also, they are support to help in making the air travel 'straighter' as it passes over everything

[Modstock]

Ive actually done those very things to that roofrack.
Made a bigger wind deflector up front and lessened the angle to match the windshield angle. Also have a small deflector at the rear.
Moving the RR back as far as I could helped alot.
Those few things were a big improvement.
To get it lower alot of cutting and re-welding would be required.
This vehicle is now retired from towing duty.
New truck with a shell taking over.

Sent from my SM-A115AP using Tapatalk

[gudmund]

a different vehicle could show some kind of a change, but looking at this picture - if that is the trailer you are still using? - with the "v'ed" front = I really don't think you could do much better than what you already have there. The only other thing is to just -like we have been saying here- getting the air to kick "up and over" the top of everything so as to clear the trailer top when it drops back down at hi-way speeds. Take care

[Modstock]

This should do better. Oh and V8 .


Now I gotta figure out how to mount the snowboard.


Sent from my SM-A115AP using Tapatalk

[gudmund]

Being I now see a canopy/topper, if you could find a set of canopy tracks (Yakima or Thule) Warning - they are not cheap = saw $$'s around $150+ for a set - found my set on Amazon for $111(new) and than was able to find a used set of Yakima mounting cross-bars from a canopy sales/lot for $25. Was quoted $50/75 for mounting the tracks, so I did it myself, came out good! - I just make sure to measure 'a-lot' thus keeping them in square/side-to side parallel with each other and be careful when drilling the fiber-glass and seal it good. (it seems to want to 'chip' when being drilled=probably not the right ?drill bit/drill speed?) Once I got the tracks mounted, everything was just an easy bolt on along with being very adaptable for different variations/angle changes for trying different set-ups. The rack you were using before may still be an option with it's angled front-edge panel (little side note-you kind of have nice 'angle reference-guide' built into this picture you posted here with that "stair-way" in the back ground on the side of that building) that could be easily re-mounted to this canopy track & cross-bar set-up I am speaking of here. This picture shows the tracks installed on top of my canopy 19Aug21 was just on E-trailer and saw that they carry 'Rhino-Rack' brand canopy tracks for about $100/115 for a set of them .......

[Dan242]

I thought alot about aero. Not just for mpg, but less strain on the tow vehicle. I built a square drop with a V nose and roof slanted downward. My door is on the rear and vertical so I added some slanted sides like the Semis use. I towed it 2500 miles a while back and fuel mileage was not far off and it pulled awesome, never had issues with Semis passing and making it shimmy etc.

[Modstock]

I picked up a kids size snowboard for $15 the other day.

(115cm=45")
Didn't want it to stick out past the edges and look odd.
Plus the kids boards are more symmetrical. Both sides are the same shape.

Had some brackets made up from some scrap had lying around.

Only problem is I can't have it upside down cause the edges hit the top when folded down.
So it'll just have to be upright.
I'll probably paint over the graphics with the OE color paint.
Haven't drilled any holes in the top yet. Working up the courage.

Sent from my SM-A115AP using Tapatalk

[Modstock]

Here's it flipped upright.
Windshield has a 35° angle to it. So im thinking at least 45, maybe 50°.

Pic at 50°.

The bug line on the trailer is the 3rd rivet down wich matches the height on the truck topper .
Folded down it looks like some guy just really wants to go snowboarding

Sent from my SM-A115AP using Tapatalk

[gudmund]

and keep adjusting it 'upwards' - till there is 'no' more "bug line" = very interesting - will have to start looking to see if mine has an established 'bug line' on it next time I head on down the road............... never thought to look take care

(and too think, the price of gas was "only" just maybe a-bit about $3. per gallon not quit a year ago when this post started - end of July '21..........)

[Modstock]

I noticed Slim's snowboard is pointed right to the top edge of his trailer and no more.
So I hooked up my trailer just to see what that angle would be. It's 30° and I'll use that as my minimum. Started cutting the rear brackets to lock it into place. I can use wingnuts for the bottom bolts and move it to another slot to get a steeper angle. Fully adjustable.
I may flip the board back upside down but would like to do some official testing before that.
The bug-line never lies.

Sent from my SM-A115AP using Tapatalk