One of the topics I mentioned early on in this tread was keeping the rear spoiler at or below the line of the Aerotemplate.
I happened to run across an example today where this was not done.
The Mustang in question did not remain in this configuration for long, the next generation of modifications appear to have been a wing placed high up in the clean air flow which certainly would have resulted in lower drag than this version I'm showing.
Unfortunately I was not able to get a good side view, but did my best.
Aerodynamics by George Kachadoorian | Photobucket
Links to the Mustang project by Vorshlag where the base images came from:
http://www.vorshlag.com/forums/showthread.php?p=57309
http://www.vorshlag.com/forums/showthread.php?p=57230
Here is a good side view of a stock Mustang from a old thread for context.
http://ecomodder.com/forum/showthrea...aps-25379.html
Based on my own pickup truck rear spoiler experiments, the larger you go the more down-force, but it can be to the point of ridiculous. For me it was like towing a large boat or having a giant child crushing down on my truck like some toy car. See the link in my signature for that experiment.
In theory, one could make a rear spoiler like the 1973-74 Porsche 911 RS which lowers lift and lowers Cd, but it might take the engineering skills of someone like Porsche to pull it off.
I'm sure they knew what they were doing even back in the early 1970's and mostly likely would exceed what the novice thinks they know by surfing the Internet. However, that's not going to stop me from having a little fun with it now.
Yep I have sketches drawn up for a rear spoiler on my old air-cooled 911, and have a buddy with a plastics shop that does fabrication. It's going to be awesome, but will have to wait in line on my "to do" list. Brakes, body work and further weight reduction comes first.
EDIT: Some interesting conversation in this old thread.
http://ecomodder.com/forum/showthrea...-25223-14.html