"cooterbaldwin" (cooterbaldwin)
09/06/2013 at 12:51 • Filed to: None
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"cooterbaldwin" (cooterbaldwin)
09/06/2013 at 12:51 • Filed to: None | 3
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!!!error: Indecipherable SUB-paragraph formatting!!! - 451.993 single run, 437.183 two run average.
RamblinRover Luxury-Yacht
> cooterbaldwin
09/06/2013 at 12:58 |
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y helo thar.
(394.19 wheel-driven, 1947 )
GhostZ
> RamblinRover Luxury-Yacht
09/06/2013 at 13:01 |
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The difference between 400 mph and 450mph is, in terms of mechanical capability and force needed to overcome friction, probably about the same as between 50mph and 200mph. Diminishing returns and all that. Really, I'm not surprised we hit 394 mph back then.
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RamblinRover Luxury-Yacht
> GhostZ
09/06/2013 at 13:16 |
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Aerodynamic drag increase, roughly speaking, is about 26% for an equivalent shape between 400 and 450. (9/8)^2. You get rid of a good portion of that between period aero and modern aero, particularly in being able to downsize the body and use even better material finish. In contrast, the aero drag increase between 50 and 200 is 1600%. Drag forces show up in an engine as well, but rolling friction of parts generally doesn't scale exponentially to the extent drag does, and past a (surprisingly low) speed drag is far and away the greatest limit.
The engines Cobb used developed 1300hp each out of a half-ton dry weight per engine. We laugh at that today - certainly more than 25% better power to weight to say the least. Sure, there are other mounting friction and strength limits than drag, but we have power capability he couldn't have dreamed of.
I'll cut some slack to the records-setting industry for taking several decades off to focus on jets/rockets, but don't think of Cobb's record as being anything less than astounding.
Edit to add: the biggest limit, which neither of us cited, is the ability to maintain traction with wheels at those speeds. That is, however, another field that has grown by leaps and bounds.
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GhostZ
> RamblinRover Luxury-Yacht
09/06/2013 at 13:50 |
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