Truck wind deflector install brainstorm, anyone have cabover camper?

[Truefire]

I was wondering if a truck with a cabover camper that protrudes approximately 8" beyond top most portion of truck windshield would even benefit from the installation of a wind deflector mounted on hood. I am assuming that it would only move air approximately 6-8" off of windshield, which in that case would deadlock underneath cabover.

Any thoughts?:xxrotflma

Chris

 

[brian90744]

cab over space

yes, hood deflector will not help. If you need a spoiler between the Cab roof and the underside of the cabover they sell a inflatable item, check with Coyote RV/Phoenix campers, Or you make a 3" or 4" plastic 90 degree angle , mount on the underside of the cabover in a "V" at the front, this should deflect windshield air around camper and not under the cabover. I started to make a deflector from a 5" plastic square post 6 ft long from the garden dept, I cut the post using a bench saw down (Plywood blade)the middle, trim to size. mine is 3" gap. Should be easy to attach to underside with car emblem 2 sided tape and screws. Each piece of the "V" should from the front center to the outside edge of the camper deflecting wind over and around the cab over and camper.
brian

 

[Truefire]

Thanks Brian, interesting. Are you referring to mounting both legs of the V on the camper and allowing the vertex to align top of windshield? Is that what you are talking about?

Chris

 

[Stumpalump]

I had a hood deflector for years and I saw a lot of bugs, birds, rocks and debris fly over the roof instead of hitting the windshield. I would be very tempted to put one on your rig.

 

[brian90744]

Kinda, "V" starts under the leading edge of the cabover. You need to leave about 3/4" gap above the cab for chassis flex. If I finish mine I will post pics.
brian

Thanks Brian, interesting. Are you referring to mounting both legs of the V on the camper and allowing the vertex to align top of windshield? Is that what you are talking about?

Chris

 

[brian90744]

camper air dam

Here's part of info from Pop-up Camper Forum by "What's new at Coyote RV/Phoenix Pop up" & offroadcamperguy thread #101.

Tightness of clearance between the top of the vehicle's roof, and the bottom of the camper's cab over. No matter how LONG the cab over is or how well designed the aerodynamic shape
is on the tip, wind will sneak into the space above the cab and creat an air dam that slows the vehicle down. The bigger the gap you have here, the worse the air dam will be. The
very best thing you can do to improve the aerodynamics of any existing truck/camper combo is to add a CAB-TO-CAMPER PAD. This is an inflatable pad that fills this gap between the cab and cab over. Closing this gap make the wind divert to either sideof the camper instead of getting trapped and causing the dam.The cab to camper pad can sometimes help other things like
"bed bounce." I very much recommend getting the 3M clear bra added to your vehicle's roof before adding the pad, in order to protect the paint.
brian

 

[1911/F-350]

I would love to see more details about this thread.

In the future I plan to do at least a scoop over the cab to improve MPG.

My truck has the same aeroyodynamics (and MPG) as my Jeep.

Like a brick.

 

[redthies]

For your rig, 1911, I would look at the folding type of wind deflector that you see on pickups towing big 5th wheel rvs. I'm sure any RV dealership parts dept could source one for you.

 

[1911/F-350]

I saw one on a snap-on truck that got me thinking.

I plan to build it myself out of aluminum and have it epoxy painted or Rhino lined black. It is a 50/50 of looks and function. This is my work truck and the company pays for my fuel so I would guess they would pay for material if it will help with fuel mileage, and I reap the rewards of a cool (to me) custom scoop.

I figure the truck and boxes mainly for work, but the rear box more for my personal pad and comforts while traveling.

I was curious how much a scoop would really help with MPG. I am currently getting about 10.8 with 4:10 gears and running the expressway. I have not switched all my work stuff or any gear to this truck yet so there is only about 200-300 lbs in the bed now.

When it is setup and loaded I will guess I will be hauling about 2,000 lbs or better every day.

 

[brian90744]

Turbo wing deflector.

Maybe a wing like this would help??

I saw one on a snap-on truck that got me thinking.

I plan to build it myself out of aluminum and have it epoxy painted or Rhino lined black. It is a 50/50 of looks and function. This is my work truck and the company pays for my fuel so I would guess they would pay for material if it will help with fuel mileage, and I reap the rewards of a cool (to me) custom scoop.

I figure the truck and boxes mainly for work, but the rear box more for my personal pad and comforts while traveling.

I was curious how much a scoop would really help with MPG. I am currently getting about 10.8 with 4:10 gears and running the expressway. I have not switched all my work stuff or any gear to this truck yet so there is only about 200-300 lbs in the bed now.

When it is setup and loaded I will guess I will be hauling about 2,000 lbs or better every day.

 

[redthies]

That is quite the wing. I wouldn't Rhino line anything to help with wind slipperiness. You would get a fair bit of drag from the bedliner.

 

[1911/F-350]

Yes and no.

I am thinking 8' wide at the top and taper down to the cab conture (3' maybe) and a lip over the windshield.

Aerodynamic yes, adding aluminum to deflect the sides, yes.

Worth the trouble and material; not sure. That's why I am reading here.

I know that one can't see the design in my head and comment on the MPG saved but was just curious if anyone had added a scoop and had some #'s.

If the OP returnes to this post I will shut up. : )

 

[doug720]

A few years ago I was involved with making some aero devices to improve the fuel economy of over the road trucks..18 wheelers. Penske and a few large trucking companies wanted to find an economical way to improve the MPG that was feasible to retrofit onto existing trucks.

What we found was no device made any difference if the it was mounted more 30 -36 inches from the sail/drag surface. What was found was once a aero device is mounted over these numbers, the wind was essentially undirected and no reduction of drag was achieved.

If you look at newer newer trucks, they have the trailer mounted close to the cab and have top and side aero devices to push the air away from the trailers flat surfaces. Older trucks had many feet of space from cab to trailer, too much to overcome with aero devices.

Also under carriage drag is being reduced with the trailer side panels mounted frame side between the tractor rear wheels and trailer wheel sets. This has been one of the largest and certainly cost effective drag reducing ideas in a long time.

Basically, mount the aero device as close as possible to the drag surface. To see if your idea is working, tape small pieces of yarn to the drag surface and observe how it moves at cruising speeds with no modifications, and then do the same test after the aero mods. Smooth and soft flow is good.

Doug

 

[1911/F-350]

Thanks for the info Doug. I am no tractor trailer but I do have a good bit of wind restiance. Did you see some MPG saved with a scoop?