i'll put some of these rumors to rest,
srt-4's with the factory turbo and about 23psi with supporting mods will do 11's.
with 21psi i did 12.57@113 on 18" all season tires, 22psi and some slicks and i went 12.1@114, the car deff has 11's in it. this was with less than $3k in mods.
the only weak link in the transmission is the input shaft, fix that and the tranny will hold 600hp+
only the 03's didnt have LSD, the 04-05 both did, but because of some ecu changed made in 05 (makes it harder to tune with piggyback), 04 IS the fastest year.
mopar has staged upgrades 1-3
stage 1: new ECU
stage 2: new ECU, injectors, wastegate, and option to add dial-a-boost, high octane mode, and FMIC sprayers
stage 3: same as stage 2 but has a new turbo-fold (bit bigger turbo in other words) if you've seen a srt-4 turbo you know why its called a turbo-fold.
it took 15psi on a 64mm turbo, about 400rwhp, to get this supra to do 116mph in the 1/4mi. which was my fastest in the srt-4 with only 286fwhp and 366fwtq
oh and in a couple months im rebuilding the short block with a new crank from dealer, and all forged internals, and a new factory MHG for just under $1100 it will then be able to handle 500+whp daily.
there really is no comparison between the supra (mk3 or mk4) and the srt-4. they're each in they're own class, but neither is really better than the other. its all personal preference.
as for the caliber srt-4.
FAIL!!!!