I remember reading here that for every time you cut the scale of a car in half, you have to double the speed of airflow to get accurate wind tunnel results.
1/1, 15mph
1/2, 30mph
1/4, 60mph
1/8, 120mph
1/16, 240mph
1/32, 480mph
So if you were going to test a 1/18 scale car in a home made wind tunnel, you'd somehow have to get the air going at around 300mph to have any usable results. Now I learn that my 4th grade science project wasn't very accurate.
