Came across this page of available downloads. Don't know if this is anything new or if anyone on here has seen it before. The download at the bottom of the page looked very interesting to me. Has definitions of lots of the different tuning values and what they do, something that I have wanted. Something that says what the different things that you can change actually do. It is mostly for mass air, of course, isn't everything? But at least it tells you a little bit of usefull info.
http://www.v8mustang.com/downloads.php