Niz22 wrote: I know mick (dr20) had a full auto tranny 5EAT rebuild , just not sure how it held up , for how long and who did it. Ive tried contacting him.
I can answer that for you. It didn't hold up very well at all. Recently dismantled it - and it had a number of issues. Centre diff output shaft was already missing a few teeth - and this was cryo treated/shot peened/linished/scanned for cracks - and only done "5000kms" to quote Mick.
The clutch packs had some issues, fluid was really really black, which apparently contaminated the clutch packs further. Box also showed signs of not being assembled properly.
What does this mean for you - can an auto hold 400kw safely? The box/clutches probably can. The c diff won't, especially if you're like Mick and you try launching it. The broken bits of the gear teeth will also float around the entire system and likely damage sensors and the VB.
"Just convert it to a manual, 6 speeds are bullet proof!" - check out Satogixxer's build. His manual isn't fairing very well at all at 400kw, and even a proper 6 speed setup like a gen4 or Sti will be stretched at 400kw, at the very least you'd easily break driveshafts on a launch.
400kw 4 cylinder Subaru engines are also not the best idea. It takes a lot to get there, and might not last very long. And I'm not talking about cars that read 400kw on a dyno, but then run the same MPH as a 300kw car.
If I was you - I'd be aiming for 300kwatw - your car will be happy with it from the engine and driveline side of things. What is the point in having a 400kw powerplant, when something breaks every time you drive it? MCM built a 270kw 3.6L turbo H6 setup, and with stripped interior managed a 122MPH, and beat an R35. In a proper 300kw Lib - you should be seeing 125MPH in full street trim - which is a mid 11 second car, and chops R35s - and realistically - what more do you need from a family wagon?