Gary R.

I think he did unless I am misinterpreting..

OGRacing

What we found was that with drip rails/gutters the air would go past the side window opening, with just a window net. When we covered the drip rail/gutter the air would come back and then turn the tufts 90 degrees into the car. Now if there was a side window in place that couldn't happen.
The air that was going over the car close to the door opening would become turbulent and the yarn tufts would be going in all directions. This then screwed up the air flow as it went back to the wing.
So one thing screwed up another thing and it just made others worse.

Bill

mark kibort

its a fascinating balancing act of flow directions, pressure diversions and drag.

bottom line, what you found probably increased drag, or made the wing less effective, where you would need more angle which would cause more drag.....

Airflow study is interesting that way, because there are so many things to balance. also, its not intuitive, as you saw.. sometimes smoothing one thing out, makes the flow change that can actually cause more drag. the net net, with my point is that even by anyone's wildest imagination, you cant get 2-3mph at daytona by a small change like that. again, 0.5mph would be more accurate of a result using very standard values in the analysis. But, that's improving aero by 1-2%, and it sounds like the net results was a loss. Also, for that 2-3mph gain, (at 150-160mph/ 200-300hp/CD .35/Fr A =2, acc time to terminal speed =30sec) you would need a 10% drag coeff reduction and you aint getting that with a little rain gutter flap!