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Old 01-10-2011, 12:13 PM   #11 (permalink)
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in theory they could help but I don't think they will "as implemented or designed"

we know "golf ball" dimples will help by making the turbulent air more energetic allowing it to follow harsher contours than it could otherwise IE reducing "base drag" (that is what we call it in rocketry not sure what its called in the automotive industry

anyway they are way too big. they add frontal and base drag ie will never offset its own frontal and base drag not to speak of the car's

made significantly smaller and placed correctly they CAN help. alas its a T&E issue as non of us understand the math of the fluid dynamics nor can we model it to figure that stuff out.

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Old 01-10-2011, 12:41 PM   #12 (permalink)
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Quote:
Originally Posted by ChazInMT View Post
They work great, I think 2-8% FE Gains are way too conservative, I bet you get 40-60% FE Gains....In fact, I'll bet you could just put them on your car and they'll just push it down the road on their own...so just go ahead and rip the engine out of your car and let the aitabs just push you around town. You better have good brakes to keep your speed in check.
Maybe if you combined them with a ridiculously huge wing, they could make the vehicle go even faster... ?
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Old 01-10-2011, 05:39 PM   #13 (permalink)
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They do work. However they won't work for all cars. They work best on cars that have a blunt rear end that is almost as big as the frontal area. Before they were commercialized the inventor tested them on a Honda Civic in a wind tunnel and was able to prove a 4 to 6 percent drag reduction.

http://www.airtab.com/MicrosoftWordHondaWTReportV6.pdf


Looking at Neil Blanchards photos I don't think he used enough of them and might have had them too far forward. The install guide says they should be positioned 4 inches from center to center(Note that this distance can be increase some to accommodate mounting obstacles and lessening this spacing causes the vortices to interfere with each other ). It also states that the front of the air tab should be mounted 14 inches or less from the trailing edge of the vehicle.
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Old 08-21-2011, 07:39 PM   #14 (permalink)
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do air tabs work, is that a valid question

if you want to run a business i don't see that is a good question. it doesn't matter if they work what matters is do people think they work. if you really must convince your self they work, i would suggest they likely do something good. if not better fuel econemy better stability. i haven't researched the air tabs patent position but i suspect it would be impossible to have a really sound position on technology that is 100 years old, so you might want to consider vacuum forming your own design that accomplished the same end.
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Old 08-23-2011, 09:59 PM   #15 (permalink)
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I always figured placing golf ball divits in all regions of turbulence on a car would do more (AKA on suspension underneith, near trailing edges, etc etc)

These were proven to work but i am uncertain if any measurable gain would be made cheating as it were.

They would likely make the right amount of turbulence as compared to the oversized air tabs.
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Old 09-05-2011, 09:56 AM   #16 (permalink)
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So the answer is no then ?
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Old 09-05-2011, 01:45 PM   #17 (permalink)
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There is a thread here on EM that showed how to use these correctly -- if there is a taper on the rear that is too steep for attached air, then you can install them *just* down the slope (on the radius transition) so they do not add anything to the frontal area, but they can slow the air flow so that it then can remain attached.

I'll look for the thread...
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Old 09-06-2011, 11:41 AM   #18 (permalink)
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Quote:
Originally Posted by Arragonis View Post
So the answer is no then ?
Nobody on here has been able to proof they do improve FE, and it wasn't for lack of trying

I still think they could work, but not in the usual massively/truck-sized variety on a regular car.

Something more subtle might do the trick.
Renault / Dacia had them on the rear roof line of their eco-Logan.
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Old 09-06-2011, 12:11 PM   #19 (permalink)
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My friend got a bunch and we put them on his Ford E150 van. I posted on here a while ago that they did not help his Cd when installed per manufacturers directions. They actually increased drag by about 3%. They did pull the trailing wake in sooner, but I don't see that as being a real benefit to most people.
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Old 09-06-2011, 01:02 PM   #20 (permalink)
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Has anyone who pulls a trailer on a regular basis tried them on the back of the tow vehicle? Somewhere on their website I remember they saying they actually saved more money in trailer tires than on fuel, due to stabilizing the trailer.

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