I love all the posts from the Manual Tranny guys about your question on teh auto tranny.... Ignore almost all of them.
Look here for advice on your auto tranny: http://legacygt.com/forums/showthrea...rd-160101.html
ClimberD and frequent contributor to his threads frank_ster are by far the most knowledgeable when it comes to the 5EAT tranny! At least that contribute to legacyGT.com.
I'm on my third 5EAT tranny. I've learned alot. My first tranny did not survive the tuning process after I upgraded my turbo the first time. Tranny had been overheated @ 58K on a roadtrip through Death Valley, 4 bikes on the roof rack, 134 degrees outside temps and pushing the car to 130mph. Bad combo for tranny longevity.
Read about fluid service on your tranny first. If you're going to go to stage II power mods, read about the Hex1 VB mod. If you're going above stage II power mods, find a tuner with experience with the auto tranny tuning subtleties.
I am well into the 350+ club. Frkkevin is closer to 500hp w/ his 5EAT.
You've got a lot of reading to do before you mod your car. Unless you want to be like me: 3rd motor, 3rd tranny, 3rd turbo. Quadruple the value of the car. Hard learning curve by not doing my research.
And there's still nothing I'd rather daily drive.