spoken like a true armchair ASSuming tuning expert. Why would you try to help him out and offer advice when you dont even have DSP5, or any knowledge about it?????? I dont understand that about forums. If someone doesnt know the answer to something, and they ask a question, do you think they would want an "answer" from someone who ALSO doesnt know the answer to the question?????
Thats like me barging in on a meeting of nuclear physicists and saying "oh hey guys, have you tried making the reactor work this way? I think that would work great!"
and no, this theory/idea of yours has zero possibility of working, for the reason that andrewjamesbond said DIRECTLY above your post. Each DSP tune does not have its own idle table.
The only way of doing it would be to use the main base-idle table vs. ECT, setting the idle speed high below, say 40* ECT. But then again, I dont know how that would affect the park/drive idle offset....if the engine would still try to use the base-idle tables even when in drive. In which case the aformentioned trick would not work, because then as soon as you put it in drive, the truck would try to push through the brakes.