Don't know about behind a turbo, but in my truck I had no problems. Overdrive kinda sucks, but with a turbo helping the HP, you should be good.
They are overbuilt just like their manual trannies.

Todd


1986 Pickup extracab longbed "Woody edition"
SAS - 33's, 5.29's, lockright rear.

02 IS300 SportCross - my "DD"
94 2wd v6 extracab
04 Outback Wagon- wife's/family car