Quote:
Originally Posted by RobertSmalls
....I think this is an unconventionally good feature, and I hope it will allow me to have an unconventionally short boat tail.
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Robert, thanks for trying anyways
My car would not give you that much better results than yours at point.
Why?
Because as much as the under-body panels cover the underside, there are still some gaping holes next to the rear tires. This occurred from running out of warm weather late last fall.
I'm still waiting for the weather in Wisconsin to get consistently warm enough in the mornings to start riding the bike to work and then start working on the Insight again. First finishing the rear wheel holes, then working on the rear extension.
If it's any help, my extension length works out to 42 inches from the rear edge of the rear tire skirts to the end of the tail lights/license plate transom. That's the length I'm building to and then we will see what type of turbulence that remains on the underside of the car.
As for rear transom height?
It will be set based on a straight line drawn right down the middle of the back window, all the way to the tail end. The underside angle will be curved gracefully to meet up the underside of the license plate.
That way the clearance can be as high as possible and the rear window curvature will simply be straight to the end. It will be slightly lower than the nice rendering by Botsapper.
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Robert, on a different note, you might want to retry that run again with side strakes as SilverInsight2 mentioned.
That will hold the air from slipping off the sides of the coroplast, and maybe giving better results.
Of course it might be that the turbulence under the car may have contributed to it as well. Mine has some large holes down the center by the cat-con and muffler, which would certainly stir things up. I might cover mine up some time, but it certainly won't be this season.
EDIT:
I just watched your video. It did work for me.
A fine tweak to smooth the underside can be made by adjusting the rear brake cable up out of the air stream. Mine was adjusted up last fall after spending so much time on my back looking at it during the panel construction. I think it's held by a 10 mm bolt and associated bracket. Loosen the bolt then adjust up out of the air flow. Mine allowed just enough play, that it's just about flush with the bottom of the panels, and that's with the rear suspension fully extended.
Jim.