I searched but did not find the expression “rotational drag” in this thread: is there a search function which looks for words just in one thread?
Anyway, this thread seems to be about credibility of hambini, but to my poor state of knowledge, “wheels” is the only topic for which a wind tunnel is the wrong analyzing tool because of that subject of rotational drag. Wonders me that the planet x disk tests so good nevertheless.
Hambini states that the wheels are rotating in these tests, so rotational drag is captured.
I don’t think it should be that surprising that a disc + 80 beats all combinations.