so i thought id chime in with my .02as well....
somebody mentioned the variablity of not only the cars themselves, but the different tracks (i.e. car A runs at track A with x mods runs y time and car B at track B with x mods runs n times).
my first S197 was a 2005 GT with an auto. i was following along with a guy from VA who had similiar mods to me but was racing at VMP up in Richmond, while i was going to No Problem Raceway when i lived in NOLA.
i had a C&L CAI, Bassani o/r x pipe, Bassani axle back, 4.10s, BMR lower control arms and a Diablosport tune from HPP racing (got it while evacuated to Ft Worth)
when i came back to Louisiana my first pass was a 13.3@104. best pass wound up being 13.2@105
The guy up in VA the only difference between our cars was he had 3.73s instead of the 4.10s. he wound up putting a couple of other bolt ons, such as underdrives and getting a custom tune and he was running like 12.7s@107.
lots of variablity, but i think with the "standard" bolt ons, gears, exhaust, CAI/tune, shifter and the most important....a good driver who knows their car these things should turn 12s in that trim.