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Discussion Starter #1
What do i need to do a sti conversion for my fxt? I already know i need the tmic, turbo and ecu but what else?
 

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Mexican Lorider
2004 FXT 5MT
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439 Posts
aph626 said:
What do i need to do a sti conversion for my fxt? I already know i need the tmic, turbo and ecu but what else?
It depends on what year you have whether you can use the STi ECU. It really only works easily on a 2004 5MT.

aph626 said:
And the injectors too? thanks for the help
The 04-05's had the same 55occ that are used in the STi, so no they arent needed.
 

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Mexican Lorider
2004 FXT 5MT
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439 Posts
Fishdizzle said:
would there be any benifits to getting a STI ecu compared to Cobb AP vf39 map?
Not in my opinion, other than maybe passing emmisions with a catted DP. The Cobb map may also be good for more power from the get go.
 

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BLUE WASABI, (#2 Info Provider)
2008 SG Model D
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9,051 Posts
AFAIK, the STi flows slightly more due to using a larger turbo but the injectors are the same size.

Basically, it depends on what year XT you are running (I think people had immobilizer issues w/ the STI ECU in '05) but you can get by w/ just this:

'04 STi ECU route
VF39,
STi TMIC
catless uppipe,
high flow catted downpipe (otherwise the stock downpipe and midpipe will be supper restrictive)


-or-

'04-'05 FXT ECU route
VF39
STi TMIC
high flow downpipe
Cobb FXT AP

Beneficial but not needed: Walboro fuel pump and Full 3" TBE
 

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Aspiring Post Ho
Joined
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267 Posts
If you run the AP vs sti ecu (04), you have the benefit of the program being modified to take into account the higher air flow resulting in the exhaust and what not. But either way works. I know I definately gained some power when I had my ecu reflashed (ecutek) and the car had alot quicker spool up and throttle response after the reflash. IMO it is worth it to get the ecu tuned either by, AP, excutek or Utec (turboxs)
 

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Aspiring Post Ho
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267 Posts
I made 294/299 using the stock injectors and pump on my 04. This is what was on the car at the time:
vf39
AEM intake (short ram)
Borla Header
DN performace turbo back (catless)
PDE up pipe (catless)
 

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Registered
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549 Posts
what about using a STI ecu and running the stage 2 for the sti .... any benifit or just waste of money? and would you be able to run the sti ecu on an 04 auto?
 

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Aspiring Post Ho
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267 Posts
I am pretty sure that is what a few people have done already and I have not heard anything negative about it. The only issue is that Cobb will not provide any support for this. We went through this one along time ago when they said they were going to make a map for us FXT guys that would account for the turbo swap but nothing ever materialized to the best of my knowledge.
 

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BLUE WASABI, (#2 Info Provider)
2008 SG Model D
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9,051 Posts
I have been running the STi Stage 2 map for a while now. Huge torque monster down low but limited up high. Definitely a good power increase of stock STi map but not as smooth and of course you get slightly less MPG.

As for '04 AT running '04 STi ECU, not a chance...there weren't any AT STi's in '04.;)

Best bet is a retune for you AT either COBB AP or EcuTek.
 

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549 Posts
ok next question would be ... they only make a VF39 map for the 04 manual ... could i use that map on the auto or am i SOL?
 

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BLUE WASABI, (#2 Info Provider)
2008 SG Model D
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9,051 Posts
Fishdizzle said:
ok next question would be ... they only make a VF39 map for the 04 manual ... could i use that map on the auto or am i SOL?
No, you cannot use a MT map for you AT...but you can get a '04 COBB FXT AT AP...then get it protuned to run the VF39.
 

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Registered
2006 '06 FXT
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835 Posts
Fishdizzle said:
ok next question would be ... they only make a VF39 map for the 04 manual ... could i use that map on the auto or am i SOL?
AT Cobb maps are available, I believe. Try emailing Christian and seeing if he can send you one. If not he can tell you when it will be available (no snide comments here, please).
 

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Recovering Modaholic
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1,304 Posts
Fishdizzle said:
i know they are aviable but just not a VF39 map
Christian does have a VF39 map for the auto 04 and 05 FXT, its just not listed on their site.

I'm sure he can email it to you.
 

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2004 FXT
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403 Posts
Noob question (maybe) about the 4EAT tranny

How much HP and torque can the stock tranny handle? Mine's stock but I don't want to overmod it and ruin the tranny.
 
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