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Old 09-08-2020, 08:38 PM   #33 (permalink)
JulianEdgar
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Quote:
Originally Posted by California98Civic View Post
Very interesting case, but your last line in post 29 does seem like a straw man argument. Nobody is arguing that absolutely any road vehicle body that someone classifies as "streamlined" is of zero lift shape. "Properly streamlined" I am sure I have seen claimed, but "properly" is a big qualifier. Seems to me Honda probably knew this shape created lift and that they may have tuned this car for a little lift to reduce rolling resistance. A question I would have would be whether this lift is dangerous. I wonder what degree of lift under yaw will "lift" the car off the road. Were there race rules that would stop the race under certain wind conditions. I would think there might have been given the lighweight and wing like shape of solar racers.

I gotta add one edit: up to 100 kph, lift is pretty modest and the car ran at about 90 kph. And I definitely have not seen anyone argue that a streamlined body under yaw would produce no lift. It is an interesting study but it proves less than you seem to think.
1. It is good evidence that one of the slipperiest cars ever made (and so surely by any normal definition, the most streamlined) had a lot of lift. (Or are you suggesting this car is 'improperly' streamlined?!)

2. This idea that for lift to discombobulate the car it has to lift off the ground is complete rubbish, and I have never seen that argument used anywhere except here. Refer to SAE papers 1999-01-0651 and 2009-01-0004 to see how quite small amounts of lift can cause problems in car stability.

3. I'll repeat the quote from Honda: "Future research and development will be required to refine the suspension and/or front lift coefficient in order to further increase the cruising speed." To draw the obvious inference, the aero lift (and suspension softness) were limiting their cruising speed.

4. I don't know of any rules to stop the race in windy condition. As far as I know, the cars just went slower - with these figures, you can certainly see why.

5. If anyone has the measured coefficients of lift for any other really low drag cars, I am very interested.
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