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Old 03-24-2018, 02:14 PM   #20 (permalink)
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Originally Posted by Vman455 View Post
If you tuft test the rear window, you'll find there's a bubble of flow detachment right in the center, at the base. I added 6 vortex generators a few inches down from the top of the rear window, angled at ~15 degrees to the direction of flow, and it kept attached flow across the entire window. Effect? Yes. Measurable effect? No.
So you couldn't measure any benefit other than the airflow remaining attacked? Even non-FE related gains such as increased coasting distance?

Originally Posted by Ecky View Post
Without a wind tunnel to test in, you're probably more likely to do harm than good with something like a spoiler, but they can help in some cases - I'm sure Honda did wind tunnel testing. Ditto with anything else you bolt or tape on which sticks out in the wind. Wings always hurt because by design they generate downforce at the expense of drag.

Pretty much the only easy, guaranteed DIY modifications are those which cover aerodynamically dirty areas with smooth panels, e.g. wheel spats, radiator blocks and belly pans.
Maybe I'm missing a point that's obvious to you. If the idea of a boattail/kammback on the end of a sedan won't work because the airflow goes over it and doesn't reattach, wouldn't it do the same thing with a spoiler, regardless of it having an aero shape or not?

Originally Posted by kach22i View Post

Looks like they run +$100, maybe a home-brew creation will be more cost effective in retrospect, especially if you mess it up the cut.
How about something like this that I posted earlier?

Originally Posted by aerohead View Post
If you like,go to the car blueprint website and check out the 3-view ,4-view images of:
*Cd 0.23 1993 Volvo ECC sedan
*Cd 0.23 2018 Audi A4 sedan
*Cd 0.22 2013 M-B CLA 180,Euro.spec.Blue.
*Cd 0.22 2017 BMW 5-Series G30 sedan
These are all non-Kamm,but industry-leading type low-drag sedan shapes,and if you'll study all the different views of their bodies,you might see some features you could use with the Honda.
One would have to basically rebuild the Honda for those...
2006 New Formula Red Honda Insight MT, 287k: (Build thread)

2013 Ember Black Volvo S60 automatic, 104k (Wife's car):
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