Vortex Generators / Hmmm Airtabs

[rh77]

There was a similar thread on this a while back

Vortex Generators

The Mitsubishi Evo vortex generators were the subject of examination, and was tested by the manufacturer. It turns out that it improves aerodynamics by a fraction of 1%.

RH77

[n0rt0npr0]

Originally Posted by MetroMPG

Don't forget fully warmed up drivetrain/tires. (Takes much longer than the engine does to reach stable operating temps.)

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Coincidentally, someone loaned me a box full of air tabs yesterday. So I'll also be running an airtab test sometime in Nov.

Very cool. Will love to see your finds on these!

[MetroMPG]

I went out looking for some thin but stiff plastic yesterday to mount the tabs in line in one big strip, so I could remove & reinstall them all at once. But I didn't find what I was looking for.

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ALSO - going to merge this thread with the original one, so the VG information isn't scattered around the site...

[MetroMPG]

Originally Posted by n0rt0npr0

Very cool. Will love to see your finds on these!

The Australian AutoSpeed web site recently ran a 4-part series on VG's.

[JanGeo]

Yeah well they need to try it on a vehicle with a LOT OF DRAG back there like the back of my xB!!

n0rt0npr0 - how big a box did you get of them AirTabs - want to send some my way??

[MetroMPG]

Originally Posted by JanGeo

Yeah well they need to try it on a vehicle with a LOT OF DRAG back there like the back of my xB!!

I think you may be onto something there. The Insight is a poor vehicle to use in these tests because its already highly optimized to minimize rear wake with significant boat-tailing.

I agree that IF the VGs can positively influence rear wake when mounted near the vehicle trailing edge, you'd more likely see the results if the Cd is bad to begin with, like your xB or my hatchback.

I still plan to try this. Just need to locate a strip of plastic or something that I can use to collectively "quick release" the rows of VGs from the top & side of the car in between A-B-A's.

[JanGeo]

Thinking about some plastic strapping material they wrap boxes with - pulled tight over the roof without any glue so it comes off easy - mount the leading edges of the airtabs to it with tape and strap it to the gutters or around the rear hatch opening or even fasten it to the rear wheel wells with hooks and put some VGs on the side too!

[n0rt0npr0]

Originally Posted by JanGeo

n0rt0npr0 - how big a box did you get of them AirTabs - want to send some my way??

I only purchased what I needed which was 11 of them. And damnit, I can't say whether they've made any difference or not because I've been trying to source a 93 GM 6 cylinder computer for $20 since I got them. Ain't found one just yet. My computer keeps on resetting its fuel table optimum - verified by a Tech1 scanner. Yeah. My tank to tank FE has been eerily close for quite some time now.

[smartzuuk]

If someone wants to define their test expectations and send me some VG or whatever, how about trying it on a smart?

[Ted Hart]

I had a '77 Gremlin (remember them?) with a small scoop-type wing mounted up-side down over the rear hatch window. This served to keep the dust and raindrops blasted off the rear glass. It worked extremely well! Isn't this the same sort of thing the vortex generators (supposedly) do?
Better MPG? The thought never occurred to me...such a tiny gain! MPG gains come from HP reduction...while maintaining a given velocity! People don't seem to appreciate this simple truth...it takes power to move a mass at some velocity. Burning gas makes the power. Less gas (more MPG) to move at the same speed is what a higher FE is about! Stirring the air a bit takes no power...and doesn't make any, either! Small wiggles on a MPG read-out are likely caused by the "noise" of the real world.