Here is a link to a description of how I would
very roughly estimate the aerodynamic coefficients of your own car design:-
http://www.f1technical.net/forum/viewto ... 14&t=21934
Ideally you would "simply" model the vehicle in very fine detail and do CFD analysis on it.....
and here is a link to a basic description of how you can determine the lap time that a vehicle will achieve around a specific race track (you will need a lot of data about the race track and the car itself in order to get a decent accuracy...)
http://www.f1technical.net/forum/viewto ... f=1&t=9280
If you're really interested in designing your own car, having its aero performance tested using CFD, and then finding out how fast it would be around a race track, take a look at the Khamsin Virtual Race Championship, of which I am involved on the side-lines. A link to the discussion thread is below:-
http://www.f1technical.net/forum/viewto ... 14&t=19456
and a link to the official website is here:-
http://www.khamsinvirtualracecarchallen ... -2015-news