Ordered Airtabs today!

[Danronian]

Great article. But I still hold that I am skeptical to see what actual results will be seen in MPG with these.

From what I understood, these airtabs should speed up the airflow and smooth it to lower the CD. So would these work on any part of the vehicle that doesn't flow as well as it could such as the wheels, or even on the back of a hatchback civic? I would assume it would given the principle of how they work, but I would guess there would also need to be flow testing done to prove there effectiveness (and to make sure they don't do more harm than good) to be sure of it.

[ZugyNA]

A hidden thread:

http://www.gassavers.org/showthread.php?t=1482

The 1st PDF shows research on how high to make them, angle to use, and where to put them. This testing was done at highway speeds.

[jeffreymccoy]

Thanks for that ZugyNA - I'll read through it all sometime this week. I decided to purchase the product instead of attempting to make them for 2 reasons:

1. It seems that the shape and angles need to be just right, and Im not that patient or precise...
2. Multiply #1 by 75 VGs that would have to be produced and you'd have one frustrated F150 owner.

Im looking forward to posting actual driving test data for the board.

[jeffreymccoy]

on my truck. I imagine it has a greater impact on the shape of a truck / van than it would on an already much more aero car.

First - the scale pics, as requested:

















Then - pics of them installed on the F150 (I may take the time to paint them red later - but most likely not.)












Finally the stats on the test route...that being a 45/55 mph bypass stretch with stoplights out, a 65 mph interstate out, 65 mph interstate back, and 45/55 mph bypass back.

Before (all current mods except Airtabs), according to SGII
23.6 / 22.6 / 20.6 / 23.7

After airtabs installed, according to SGII
25.7 / 24.3 / 22.0 / 25.6

Appears to be a solid 2 mpg gain (7-9% increase).... It was also pretty cool to "see" them working. I drove under a falling leaf. It would normally have hit my windshield and bounced over. Today, I saw it falling and then get rushed up over the windshield without ever hitting it, so it would appear that the tabs on the hood are indeed directing airflow over the windshield to some extent. Granted, this was one lousy leaf... it will be interesting to see if this trend continues (lots of falling leaves this time of year), and if I have the same experience noted by the other guy - a cleaner windshield...

Cheers
-Jeff

[SVOboy]

Damn, you ordered a buttload of them things...

Any chance you'd be interested in doing a string test and filming while driving before and after?

I have to think about making some for my crx now...zugy NA's write up is pretty good, dunno how I never saw it before,

[jeffreymccoy]

I think that would be difficult to do for three reasons...

1st - the tabs are stuck on pretty good, I "could' get them off, but I'd be afraid of them not reattaching as well once they were pried off. This would disappoint me greatly and cost me more money (in the way of new adhesive of some sort).

2nd - I dunno how to do a string test, but Im sure someone could describe the proper method. I would be willing to do it if Im able on the existing setup. Perhaps windtunnel test results could be found on google somewhere for a stock F150 (I can try to find that). If not, here is a stock dodge that provides some evidence of a before - albeit not my exact truck.

http://web.archive.org/web/200304142...er/Tonneau.htm

3rd - I dont own a camera, and would need to get someone to assist me that does. I assume that the filming also needs to be done by a chase car? So I just need to find the right assistant (someone with a camera who is willing to help me out)

Let me know how to do the testing, and if this would provide any value to folks, and Ill see about pursuing it.

[SVOboy]

Eh, don't worry about it. I'm sure treb will mock one up and run it through his water machine a school in a few days time anyway,

[2TonJellyBean]

Just use someone else's fee-zoh (f150) for the control string test...

[trebuchet03]

Thanks for those pictures - thanks for the extra measurements too - I can make a spline to get pretty close to that curvy shape They help a whole lot

Eh, don't worry about it. I'm sure treb will mock one up and run it through his water machine a school in a few days time anyway

I wish, I don't have direct access to the water tunnel anymore :/ Perhaps within a few months, I can see about using it though (when it's filled for other classes)

[SVOboy]

Oh, poo...I wish all my friends weren't crappy econ majors and mehbe I could make them do something like that...