From what I've seen you could build a good wind tunnel if it was you and Bill Gates. The tunnel BMatthews wrote about Micheal Selig doing his test in was own by Princeton U. very hi-tech and he still had to do all his testing at night so thermal generated winds wouldn't mess up the test, each one ran for some 6 hours if I remember correctly. Micheal's tunnel was about 3'x3' and it was only good for testing a small wing section. I made a section for the tunnel, (FX60-100), and modified one, (E-214mod), worked really hard to get them exact.....but they were not exact. I think the vacuum bagged sections from Calif. where the best, It's a lot of work for something that's not going to fly.

I think you get good results from full models with sailplanes, but not with power planes. I tested my Saggitta in dead air, 5am, and could get 3 minutes 25~30 seconds repeatedly, my Windsong 5 minutes 20~25 seconds repeatedly. I knew the Windsong was better, but if you put a motor on them and the Saggitta got better performance, was it the motor or the plane.

Dave Thornburg wrote an article I'll always remember, it was titled "Sharks fly better." What he pointed out is look at the beautiful fillets on the fins, the slow changes in cross-section. If you make ever effort to make your plane a "Shark" it will be a good flyer. Take a boxy airplane and "Shark" it up, it will always fly better.