there are a number of variables that will affect your times, such as existing mods (if any), launch technique, air temp and such, for example, a fast launch on a hot day will yield (in my experence) a slow E/T but the end speed won't suffer, on the flip side, on a cool day with a slow launch can yield a faster time and an end speed around 90 mph
As for the auto box gear ratios, from my research there is no shorter first gear in the v6 auto trans that Mitsu made (the 3000gt trans doesn't count as it is a diffrent design), but there might be a way of shortining up second gear (tops out at 80ish mph), the guts of a 2004+ Endevour 3.8 awd auto trans has slightly different ratios, first and third are the same, but second is shorter and fourths is taller, but as of now, nobody has done a gut swap (switch gears, shafts, planetaries ect) on an auto trans, so this might not work. Another part that would improve your acceleration (off the line in particular) would be a high stall converter (brake torquing can reach higher rpm's and this yields faster launches and the car can get on the power faster), I can't quite remember the manufactor that makes them, but they come in two variaties, a 3500 rpm stall good for 300whp and a 4500 rpm stall good for 450 whp.
if you want better acceleration, it would be much easier to swap in a 5 speed manual from an Eclipse, with this, the standard GT 5 speed has longer gearing and the GTS 5 speed has shorter gearing
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