I don't want to overly labour the point, but this thread is a good indication of what has gone utterly wrong with this forum (and I am referring only to the aero section; I don't read anything else here).
1. I link to a current, free and excellent paper that is relevant to anyone aerodynamically modifying their cars - no matter its shape.
2. The article has the potential to correct a lot of errors often made here over the years (eg that fastback shapes have low lift - they don't).
2. Some good debate ensues - including picking up a mistake I made in citing a particular diagram. (Absolutely fine.)
3.
But Aerohead then enters.
(1) Aerohead disagrees with what the paper calls a 'fastback', despite the shapes in the paper all being based on widely agreed current definitions - in fact the standardised
DrivAer models used in much current aero literature.
(2) Aerohead sees it as a good opportunity to hark back to his favorite hobbyhorse, the aero shapes of the 1930s. About as relevant are these shapes as, well, the air/fuel ratios
Ricardo was using in his test engines in, um, the 1930s. Aerohead's point has almost nothing to do with modern car shapes.
(3) When challenged, Aerohead asks for justification. Current references are cited, but since Aerohead doesn't read any current technical references, that doesn't help.
(4) Aerohead starts to become more and more bizarre in the statements he makes. He writes things that have absolutely no justification, yet alone any foundation in evidence, and that are in fact disprovable by a 2-minute web search. (Like that a Porsche Macan has separated flow on its roof. Just so wrong that it's honestly literally laughable - like, early this morning, when I read that, I actually laughed out aloud.)
(5) I now await the entry to the thread of:
-
Freebeard (He will say: "A Type III Volkswagen of 1962, if equipped with a Coanda rear duct, has a drag coefficient dramatically different to a Type 1.")
-
Vekke (He will say: "Do you have no politeness; how can you be so rude to someone who has helped so many people, and anyway, turbulent boundary layers behave differently.")
-
California98Civic (Very quiet recently, perhap as he realises how much Aerohead says is completely wrong, will say: "I believe in the template and I think it is completely right for everything.")
- and then,
and I won't name them, people who
genuinely want to learn, and perhaps who didn't understand much of the paper, and who will take their cues from the misleading subsequent posts and so, thinking that obscure language equals the route to understanding, will ask stuff like "So if the template has a turbulent boundary layer and is influenced by vorticity, will base pressure be mutilated by Koenig-Fachsenfeld's 1941 theory?"
And so a clear, free (
and as correct as we can find right now) tech paper on car aero will be subjugated to the steam roller of BS that is (largely) this forum, and knowledge here for amateur car aero modifiers will be set back yet another increment.