Roof Tent Fairing Thread

[digitalferg]

I've just picked up a roof top tent for the top of my 3rd Gen 4runner. I plan to mount it towards the rear (centered over the rear axle) on the factory roof rack rails and I'm trying to figure out what to do for a fairing to try and cut down the drag. I've found this thread talking about fairings but its geared more towards whether or not a fairing does anything. I'm looking more for ideas on where and how to mount the fairing in relation to the RTT in order to minimize the drag. The tent is 47"x47"x12" when packed up.

So what are your ideas and thoughts on a fairing? Any idea where would be the best position to mount the fairing so as to best push the air over the tent at highway-ish speeds? Given that if the fairing is too far in front of the tent it might hurt more than help and if its too close to the tent it might not do much of anything.

Also, what's a good design? I figure that the smaller the slope, the better the airflow which would result in less drag... but not sure I want a 4 foot long 15-degree fairing sitting up there. At least I don't think I do...hmmmm...actually that might not be such a bad idea... I won't be running with the tent 365 days a year so putting up a 4 foot long fairing when I put up the tent prob won't be that much more work. (Sorry, kinda thinking out loud a bit now.)

So throw up your thoughts and ideas if ya feel so inclined.

-Ferg-

 

[ttora4runner]

I've just picked up a roof top tent for the top of my 3rd Gen 4runner. I plan to mount it towards the rear (centered over the rear axle) on the factory roof rack rails and I'm trying to figure out what to do for a fairing to try and cut down the drag.

-Ferg-

Ben, just a heads up SOAZ (Tim) ran a roof-top tent on his 4runner using the factory roof rack cross bars and they ended up breaking on him. So you may want to look into as well.

 

[LandCruiserPhil]

My 1st idea when I purchase my solar panel (13"x50")was to use it as a fairing for the RTT. In the end I mounted my panel flat in front of the RTT and rely on my hoist to take it off and on and its only on when I need it.

My RTT (48"x48"x13") on our LC cost me 2mpg and moves my LC around more at hwy speed then when towing our popup.

I dont about 4runner factory roof rack but I fab up some quick mount for the LC factory RR and have had not problem with the factory rack and it has been tested.

I would spend the $$ on a hoist, its quick and easy.

 

[digitalferg]

Ben, just a heads up SOAZ (Tim) ran a roof-top tent on his 4runner using the factory roof rack cross bars and they ended up breaking on him. So you may want to look into as well.

The roof rack cross bars? Or the roof rack rails? Cause I will not be using the factory cross bars. But I will be using the factory roof rack rails.

-Ferg-

 

[digitalferg]

[Continuing hi-jack of the thread]

Ben, just a heads up SOAZ (Tim) ran a roof-top tent on his 4runner using the factory roof rack cross bars and they ended up breaking on him. So you may want to look into as well.

The roof rack cross bars? Or the roof rack rails? Cause I will not be using the factory cross bars. But I will be using the factory roof rack rails.

-Ferg-

Ah. Looks like you did indeed mean the factory roof rack cross bars (see pic). I would never have dreamed of using the factory cross bars :Wow1:. I do however worry slightly about the factory roof rack rails. But, I won't be running the tent all the time and ultimately I will moving it to an off-road trailer.

(Pic from SOAZ Tims 4Runner build thread)

Looks like he changed it after a bit to something a bit more sturdy:

-Ferg-

[/OK. Now back to the fairing topic. ]

 

[ttora4runner]

You beat me too it but it looks like you found the answer. What are you going to use in place of the factory cross bars?

 

[digitalferg]

You beat me too it but it looks like you found the answer. What are you going to use in place of the factory cross bars?

I'll be using these for the mounts/feet as I already had them kicking around (the actual ones look slightly different than in this photo, but you get the gist of it). The RTT I'm getting comes with aluminium cross bars already mounted to the floor and one only needs to mount to those somehow. SOAZs tent above has them as well, but his are running parallel to to the factory roof rack rails, I will be running them perpendicular to the roof rack rails. I've already communicated with the vendor of the RTT I'm getting and they've signed off that this will be a good setup for the tent so I'm gonna give it a go. :costumed-smiley-007

I am expecting this setup with these mounts to be a bit involved in getting it all mounted up and squared away, etc, etc, but I'm cool with that.

-Ferg-

Defender DS Mounting Bracket

More info on using these mounts:
Roof Tent Mounting Options Thread
new smaller CampingLab tent and awning!! thread

 

[shogun]

Hint;
In low-speed, subsonic (incompressable) flow, you do NOT want sharp edges or angles. It in fact can increase drag and instability. You do want a nice stable stagnation point.

IOW, a nice half-round, or slightly parabolic leading edge is more productive than a pointed one. A trailing-edge fairing may also be advantageous.

 

[roadkill]

you could try these http://www.airtab.com/en/

http://www.airtab.com/en/Product_Applications_24/Women_In_Trucking_28.html

Received by Airtab on May 23, 2008

Jack,

Here are photos of where I mounted additional Airtabs on the cab of my truck. There is no longer an obvious bug line across the front of my freight box! The Airtabs on the curve of the sleeper are obviously redirecting the airflow up and over. The other day when I was driving into a headwind there seemed to be less buffeting of the truck. I don't notice as marked a difference in the amount of bugs on the front of the sleeper by the stacks as I'd been hoping, but even better the back half of my fenders stay cleaner in the bad weather. That's good because those black fenders usually act like dirt magnets. I think anyone out here with a mid-roof sleeper should be looking at Airtabs as an inexpensive alternative to a fairing or whale tail.

Thanks for a great product.

Jeanie S.

I've read where some truckers were using these on their hoods to force air over the windshield (think bug shield without the aerodynmic hit) don't see why they wouldn't work in your app. I tried them on my hardtop and have noticed that the rear glass stays much cleaner when driving thru the rain. haven't tried them like you will but from what I've read they will work.