Air Tabs...anyone?

1nshort · 04-14-2013, 12:26 PM

I am thinking about looking into Airtab Industries Aerodynamic tabs. Anyone out there have any experience with this or know of anyone that does? If not, I am willing to research, buy, install and report the results.

Link: Aerodynamic Fuel Economy Savers for Road Vehicles
If you read anything at this site, the ExpediteNow PDF article explains the theory behind the system, mathmatically and in plain words. Makes very good sense to me as it jives with everything I know about submarine hydrodynamic flow vortices caused by hull appendages and how to mitigate them. The theory is the same the medium is different (water).

Interesting read. Just keeping the rear of the rig cleaner and reducing the air vortices would be worth it. Collision of Big Rig and RV rear vacuum wakes can almost be eliminated and the turbulance from being passed by 18 Wheelers. This adds to rig stability. That is if it works. The science behind it seems to make sense.

**ependydad** · 04-14-2013, 03:56 PM

Have you searched the forum? I thought I remember a reference to this 6 or so months ago...

TURBS · 04-14-2013, 04:06 PM

There was a post on this

1nshort · 04-14-2013, 04:25 PM

Yes. I read them, mostly everyone did a critique of gas mileage. From some of the research I did any gas mileage increase was marginally fractional. At that low a level it is statistically unprovable/insignificant. My main interest is stability and lessening of the crud effect at the coach rear. Most every blog I could find talked about those effects. Also most blog/comments were 2010 and before, I was hoping for something newer. I might just go ahead and do it then report results for everyone to consider. Cost is fairly small, might run a couple hundred.

OldCoot · 04-14-2013, 04:55 PM

I put them on the back of my 08 Flagstaff 831RLSS up both sides and across the top. They did stabilize the trailer from semis & buses passing. How much it helped, I would say at least 75-80%. As for keeping the rear of the trailer cleaner, it helped but can't say for sure but it was noticeably cleaner on our trips to FL, IL, MO, AR and around. Gas mileage, couldn't tell any difference, but the stability was definitely better.

Roll · 04-14-2013, 07:13 PM

Certainly is interesting. I would like to know how it comes out. I'm a project behind since I haven't ordered my LED lights yet, (but plan to soon).

Roll

garbonz · 04-14-2013, 07:23 PM

Pretty cool looking.

1nshort · 04-14-2013, 07:31 PM

Thank you for the feedback. My first priority is the stability, glad to hear you had a very noticeable result. From what I understand is that the devices elliminates or nearly so, the 'vacuum' wake at the rear of the unit. This vacuum is what sucks dirt and road spray into the unit. I will contact the company and set up a purchase.

Rolling buckeye · 04-14-2013, 07:35 PM

Quote:

Originally Posted by OldCoot

I put them on the back of my 08 Flagstaff 831RLSS up both sides and across the top. They did stabilize the trailer from semis & buses passing. How much it helped, I would say at least 75-80%. As for keeping the rear of the trailer cleaner, it helped but can't say for sure but it was noticeably cleaner on our trips to FL, IL, MO, AR and around. Gas mileage, couldn't tell any difference, but the stability was definitely better.

Interesting. I gained 11' and 4-5000# with new TH,smaller,old one 22' didn't faze our f350 srw,but after a highway test next wknd,this may b very interesting.

OldCoot · 04-14-2013, 09:17 PM

Quote:

Originally Posted by garbonz

Pretty cool looking.

Sure made an interesting conversation pc at campgrounds too!

Twisty · 04-14-2013, 10:25 PM

I asked about them once.
I am not concerned about mpg gains, it is the stability gain I was curious about.
http://www.forestriverforums.com/for...nce-33714.html

OldCoot · 04-14-2013, 10:33 PM

Quote:

Originally Posted by Twisty

I asked about them once.
I am not concerned about mpg gains, it is the stability gain I was curious about.
http://www.forestriverforums.com/for...nce-33714.html

All I can say is they definitely help the stability. As I said before, I put them up both sides and across the top.

Dave_Monica · 04-14-2013, 10:37 PM

Quote:

Originally Posted by OldCoot

All I can say is they definitely help the stability. As I said before, I put them up both sides and across the top.

The photo you posted was a TT. Did you put them on your 5W too?

Dave

OldCoot · 04-14-2013, 10:41 PM

Quote:

Originally Posted by Dave_Monica

The photo you posted was a TT. Did you put them on your 5W too?

Dave

No, haven't had a problem with semi's or buses yet on the 2 trips to FL. If I encounter the problem on the Goshen-IL-MO-AR trip, I will buy enough to do the same on the 5ver. They did help tremendously on the tt.

Roll · 04-15-2013, 07:00 AM

Affect for stability when being passed by a semi-truck.

With a large truck passing me on my left I typically feel a push to the right as they start to pass and then just as I see the end of the trailer going by, I feel a pull to the left.

How would installing the air-tabs on my coach (to mitigate the vacuum behind my vehicle) help with either of those effects?

It seems to me I need the driver of the large truck to install them on his rig to mitigate this push/pull effect when he passes me since it is his rig pushing air out front that pushes me off the road and then the vacuum behind his trailer that pulls me back to the left.

As you can tell I don't fully understand how creating these vortexes around the rear of my rig helps me with the push/pull.

OldCoot · 04-15-2013, 07:06 AM

Quote:

Originally Posted by Roll

Affect for stability when being passed by a semi-truck.
...As you can tell I don't fully understand how creating these vortexes around the rear of my rig helps me with the push/pull.

Don't know how or why they work, but from my experience with them for over 4 yrs, they work.

1nshort · 04-15-2013, 04:26 PM

Quote:

Originally Posted by Roll

Affect for stability when being passed by a semi-truck.

With a large truck passing me on my left I typically feel a push to the right as they start to pass and then just as I see the end of the trailer going by, I feel a pull to the left.

How would installing the air-tabs on my coach (to mitigate the vacuum behind my vehicle) help with either of those effects?

It seems to me I need the driver of the large truck to install them on his rig to mitigate this push/pull effect when he passes me since it is his rig pushing air out front that pushes me off the road and then the vacuum behind his trailer that pulls me back to the left.

As you can tell I don't fully understand how creating these vortexes around the rear of my rig helps me with the push/pull.

Roll,
Go to the following site and read the ExpediteNow.com Article and the Family Motor Coach Magazine PDF. It will explain things a bit better. Essentially the interactions of both stern (rear) wakes and bow (front) wakes causes the effect you are describing, it is a push as your stern wake interacts with the other vehicles bow wake and a suction as your bow wake interacts with the trucks stern wake. The reversal of the effect you are seeing occurs as you change roles (his bow your stern, your bow his stern, dynamic wake reversal). By eliminating one of the wakes, there is no to little interaction which greatly reduces the effect.

http://www.airtabs.com/news.html

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