I agree with Andy
I run a much different setup at TMS than Topeka, even if you run in a later heat there isn't as much grip as Topeka on a bad day
for reference, we ran a regional on the same lot one week before the Tour
again, STS2 ran 1st heat
it was damp in about half the lot due to an earlier rain
I ran a full 10 seconds faster on my second run after it was totally dry -- no spins or crazy stuff -- just no grip at all, sort of like ice
almost everyone in that first heat ran 10-15 seconds faster, first to last runs
only good thing is that you don't get any tire wear
FOR SALE 1993 Miata STS2
1992 STS2 Miata
1993 Spec Miata
2003 Corvette Z06 retired to cruiser