i have a 93 sc3 (c.a.i,headers,exhaust) automatic..

i wanted to tune/add an apexi safc tuner but i'm not sure if it will cause complications because sometimes when it comes to heavy breaking i downshift to cut speed and use the overdrive, will changing gears in an automatic car cause complications with the tuner/tuner settings that can harm the engine or will the cars computer automatically recalculate the settings to make it something safe to the change in gear since its programmed to drive in "d" and not to be changing from "d" to "2" "L"??? or vice versa L,2,D

 

I honestly think that you should worry about the transmission before tuning. Sounds like you beat on it pretty good .
But to answer your question. I say best person to ask is the tuner that will be working on your car.

 

im no expert but it seems like your over thinking it. I say go for it.

I dont see any reason why a piggyback air/fuel computer would bother with your shifting at all. But one thing i will advise since you sound like you like replacing your shift solenoids and other important parts in your auto get a big tranny cooler, they are cheap and you definetly want one specially how your driving

 

i dont change the gears often, its rare when i slamm on breaks only when necessary