David McCoy <gdm@po.cwru.edu> writes
> But seriously folks, It would be interesting to hear what the COD is for
>"modern designs". I have a feeling that the Mog is not all that bad, and the
>wings ought to give nice ground effects exp in the bigger Morgans that can
>get up to speed. But I defer to our racing brethern for comments.
The calculated Cd quoted for the Morgan was poorer than .5 or so, many
moderns can better .30, but normally only the basic model, as the more
upmarket ones have wider tyres. A modern European super-mini, say an
Opel/Vauxhall Corsa has a declared Cd of .32, shorter cars are much
harder to effectively streamline. The Audi 100 of the early '80s had a
Cd of .29, affixed to the "C" pillar for effect. I'm told that a Lotus
Elite had a Cd of .24, which will go some way to explain why it was so
fast for so little power.
My 4/4 goes much further to the gallon when I have the hood up and a
large plastic clamshell suitcase on the back rack. Presumably, the hood
and suitcase tidy up the rear airflow, providing a decent Kamm tail,
like an Alfasud.
Further to Martin's comments about taking the windscreen off his +8,
taking mine off makes 10mph difference to the top speed. With the hood
off and the screen on you can see a tumbling eddy blowing your
passengers hair around and these standing eddys will generate a lot of
drag.
Any guesses on a Cd for a Morgan less windscreen?
--
Jeremy Edwards
1972 Morgan 4/4
1970 Opel GT
Melton Mowbray, England
|