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stock 4EAT how much can it take?

('03-'05) 
3K views 18 replies 7 participants last post by  Thebikeninja 
#1 ·
Hi!

I was wondering how much HP and Torque can the Stock 4EAT tranny take?

my planes are:

x TD04 turbo
x walbro 255 fuel pump
x perrin uppipe
x H&S backbox and rear centerpipe 2.5"
x STi TMIC 21820AA252
x remap

not sure how much HP i will get out of this configuration either..

the car is a 04 2.0XT


Uhei.
 
#3 ·
And by the way, from what I read/researched you should be ok at 300 whp and lower. And no way you will get anywhere near that with the stock TD04 on an automatic. Just my 2 cents too: if you are going to mess with the exhaust get a full 3" to the cat. don't bother with a 2.5". The only thing I would use with a 2.5" is a cat back, especially if you are getting it tuned. And unless you are planning further mods I wouldn't bother with a fuel pump with what you're getting done, you will be more then ok with the stock fuel system.
 
#8 ·
If you're going to do that, I recommend the VF34. It bolts up to the STi intercooler painlessly and it's a sweet turbo... Spools up nice and fast as its ball bearing, not roller bearing. Makes your car sound like an aircraft too! Lol. DEFINITELY go 3" to the cat and at least 2.5" cat back in that case. Still at that point your stock fuel system is ok though. Any further and you would need something else.

Gurgroove, what's your gas mileage like? I've been considering throwing a TD05 in.
 
#14 ·
I have had my issues with our 07 VDC trans. The oil pump failed and the trans died. I didnt share it as I can not say the failure was a result of the power or just a weird thing.

My take on the sti tmic and tdo4 is alignment. Do they align well? I have had enough of a hard time to get the smaller oem tmic to clear the td04, I would think the sti would be more difficult, but doable.
 
#15 ·
Im not saying its a horrible idea to go to 2.5" only, just that if you are going to mess with the exhaust I would go big right off the bat. There are 3" systems that don't add much noise. My invidia 3" to STi cat back is a little noisy, but I rather enjoy the noise... Combined with the VF34 it's a unique tune!

That's another reason I went with the VF34 as well, it's completely painless installing it if you have an STi intercooler. All the stock connections go on fine.
 
#17 ·
And I should say: I'm saying 3" from the engine to the cat back. If you're thinking about a new turbo, definitely do a 3" downpipe and a high flow cat. 2.5" after that is fine. If that's too much money, scrap the fuel pump and STi intercooler and get the DP instead. Just my opinion.
 
#18 ·
Same here - 3" from the engine to the cat-back. I'm pretty sure that's what the OP was asking about. I don't know of any aftermarket down pipes smaller than 3 inches. My setup is catless, which is smelly and more than slightly louder than catted.
 
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