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Old 04-10-2008, 06:33 PM   #32 (permalink)
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Originally Posted by trebuchet03 View Post
I'm not looking for transferability - but there was a blanket statement made that applies to vehicles with streamlined undersides.
Yes, but the statements I quoted were originally in the context of cars and trucks. And this thread started out being about cars. Sorry if that wasn't clear. Not saying your comment about lowering the height wasn't interesting or useful--just wanting to make sure I really understand the import of it.

tasdrouille: If you only look at the extremes (avg daily driver vs. streamlined concept car) maybe things are as clear as you suggest. But what do you tell the person who has put a smooth belly pan on his car and wants to know if he should also raise or lower the height? Also, many cars coming out today have smoother undersides than cars of ten years ago--what do you tell their owners? (And while I admire the spirit of "just try it", some of us have limited time/resources and need/want to put our time/money where we'll get the most bang for our buck.)

CoyoteX: if you're really interested in interactions between the wheel and the wheel well, have a look at SAE paper 2002-0105209. Reducing drag in that area isn't straightforward--even the guys with the moving floor wind tunnels and CFD technology take a lot of trial and error to improve it. The message from that paper (to me) was: just putting the wheel higher in the well doesn't necessarily improve overall Cd.


Last edited by SteveP; 04-10-2008 at 06:34 PM.. Reason: Removed "is" (can you tell I'm a programmer??)
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