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Old 08-14-2009, 03:50 PM   #39 (permalink)
orange4boy
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Join Date: Aug 2008
Location: The Wet Coast, Kanuckistan.
Posts: 1,272

The Golden Egg - '93 Toyota Previa DX
90 day: 31.91 mpg (US)

Chewie - '03 Toyota Prius
90 day: 57 mpg (US)

The Spaceship - '00 Honda Insight
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Quote:
Stick a couple of VG's in there and she'll be right!
I love the idea of VG's too, but I can still change the angles easily at this point to fine tune it.

I had disappointing results with the mpg and seat of pants from the new back. I thought the angles were wrong. Top was 15-17 and sides were 15-20. I changed to 12 top and 12 sides but the van still seems to be sluggish on coastdown. It was much better with just the short extensions. It's possible the cooler weather is affecting the results. Just how much difference is there in air density between 85F to 70F? If it was working well one would think that the benefit would out-weigh the change in temps. One might be wrong, though.

Or could the half shell create some massive vortex, increasing drag, as postulated in previous post?

Of course it could be a dragging brake or some other increased friction like a toast bearing. I guess I should take the sucker off and try it that way. OR...Cardboard and ductape it for now.

I picked up my new taillights. I wanted red strip LED's but i couldn't find any DOT approved.
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Vortex generators are old tech. My new and improved vortex alternators are unstoppable.

"Itís easy to explain how rockets work but explaining how a wing works takes a rocket scientist."
-Philippe Spalart


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