Very lengthy and exciting read, RedSX. I'm as amazed as you are to find that just a fresh set of meats kept you planted two seconds quicker around the track; even during a "not-so-great" run.
Are you running carpet 10° radials all around or just on the rear? Also, what was your previous tire setup?
I have yet to make it out to Ann Arbor myself, lol. Maybe with you going it'd give me that extra "nudge" I need to get me over there.