On Thu, 25 Jun 1998 21:04:44 -0600, "Todd Heckel"
And this is where you gloat :).
Mike
Further to the debate on drag etc...
The total drag factor on a car is the product of the frontal area and
the drag co-efficient (this is from memory btw).
An aerodynamic car such as a Vauxhall Calibra (sorry can't think of a US
Example) has a co-eff of about 0.26 (currently lowest - the ads said)
A modern family car such as a Ford Mondeo will be about 0.32
A boxy car - such as the old Audi Quattro will be over 0.4!
Note that this figure is only affected by the ease of flow around the
body NOT the frontal area. For example a Boeing 747 may well have a
lower drag coefficient than an Audi Quattro, but the 747 will still have
to overcome more drag!
I would think an F1 or Indy car (on a road /street course) has a fairly
high drag co-eff - simply because the designers trade of drag co-eff
against creating more downforce by sticking wings in the airflow. Of
course the frontal area is quite small - smaller now with F1's narrower
cars and tyres.
So by multiplying then together we have drag. This is the tricky bit....
Obviously, when the car is stationary we have no aerodynamic drag
(Unless it's windy but thats just silly). I cant quite remember how this
figure translates to how much power you need, but I do remember reading
that for a normal car you need to have five times the power to do double
the speed. Before you tell me that an F1 car could do over 110 MPH with
140 BHP remember - an F1 car or any other track car never reaches its
absolute maximum speed - they are always geared for the longest straight
- don't know if this applies to the Mulsanne at Le Mans though...
Hope this help's -
Btw the downforce on an F1 car dramatically increases rolling resistance
as well as drag.
Surely someone who reads this group is or knows an aerodynamacist....
--
Michael C Wallace
