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2004 Forester XT 4EAT
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38 Posts
Discussion Starter #1
I know this topic comes up a lot, and there is a lot of information out there. I have been reading about this subject on and off for a few years, I have dozens of bookmarks, and I am still a bit lost on how I want to approach this.

I appreciate any help anyone can provide in navigating me through this process.

My car is a USDM 2004 FXT with a 4EAT. The drivetrain has 200,000 miles on it and I am planning an engine rebuild in the near future with power goals in the low to mid 400whp range. I have considered doing a built 4EAT with VTD center diff conversion, but I'm not sure that setup on the stock diff would handle 400who. I am trying to figure out what is really involved in a 6MT swap with what we know in 2019 after so many people have done it.

Most of the threads I see that detail the process are people who were figuring it out as they went and are often from 2010 or earlier, so the information is almost 10 years old at best and is often not terribly well organized. Also, a lot of the people who seem to know the most about this stuff don't seem to be active in the community anymore.

I have JDM STI v7 wheels and a bunch of suspension upgrades I would like to keep. So maintaining 5x100 hubs for my wheels and whatever I need to do to ensure my other suspension upgrades (KYB ADX struts for WRX, sway bars, various bushings, etc.) are still usable would be really nice. If it turns out that a full STI swap is ultimately a better end result I'm not opposed to that, but I'd certainly like to keep as many of my current upgrade investments as I can.

So as for specific questions:

Which 6MT is the best choice? I want DCCD and I understand that certain versions of the transmission have better gear ratios, the 07 and spec b get mentioned a lot. On top of the gear ratios it seems certain options make integrating the speedometer more difficult.

Which rear diff options do I have? Is there an R180 setup that allows me to keep my wheels and/or struts? I haven't upgraded my brakes yet so a Brembo swap would be great but I'm ok with the 4-pot/2-pot, or other aftermarket options if they make the rest of the job easier.

What parts are essentially universally needed no matter how you approach the swap? Things that come to mind are cross members, subframe components, pedals, slave cylinder, interior parts, etc.

What is the easiest path to working ABS, Cruise Control, and no strange electrical issues with this swap?

How is the ECU and TCU dealt with? I have seen some early swaps using an STI ECU and some others modifying the stock ECU to work with a manual transmission. I have also seen some mentions of keeping the 4EAT TCU in play for some reason. Not clear on the best approach here. I have a Cobb AccessPort if that matters.

What is a common approach related to the MT gauge cluster? Is it common to just keep the stock 4EAT cluster? How can your deal with the odometer if you do swap the gauge cluster?

Thanks in advance to anyone who takes the time to reply to me!
 

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Registered
05 Forester xt 6speed
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10 Posts
I know this topic comes up a lot, and there is a lot of information out there. I have been reading about this subject on and off for a few years, I have dozens of bookmarks, and I am still a bit lost on how I want to approach this.

I appreciate any help anyone can provide in navigating me through this process.

My car is a USDM 2004 FXT with a 4EAT. The drivetrain has 200,000 miles on it and I am planning an engine rebuild in the near future with power goals in the low to mid 400whp range. I have considered doing a built 4EAT with VTD center diff conversion, but I'm not sure that setup on the stock diff would handle 400who. I am trying to figure out what is really involved in a 6MT swap with what we know in 2019 after so many people have done it.

Most of the threads I see that detail the process are people who were figuring it out as they went and are often from 2010 or earlier, so the information is almost 10 years old at best and is often not terribly well organized. Also, a lot of the people who seem to know the most about this stuff don't seem to be active in the community anymore.

I have JDM STI v7 wheels and a bunch of suspension upgrades I would like to keep. So maintaining 5x100 hubs for my wheels and whatever I need to do to ensure my other suspension upgrades (KYB ADX struts for WRX, sway bars, various bushings, etc.) are still usable would be really nice. If it turns out that a full STI swap is ultimately a better end result I'm not opposed to that, but I'd certainly like to keep as many of my current upgrade investments as I can.

So as for specific questions:

Which 6MT is the best choice? I want DCCD and I understand that certain versions of the transmission have better gear ratios, the 07 and spec b get mentioned a lot. On top of the gear ratios it seems certain options make integrating the speedometer more difficult.

Which rear diff options do I have? Is there an R180 setup that allows me to keep my wheels and/or struts? I haven't upgraded my brakes yet so a Brembo swap would be great but I'm ok with the 4-pot/2-pot, or other aftermarket options if they make the rest of the job easier.

What parts are essentially universally needed no matter how you approach the swap? Things that come to mind are cross members, subframe components, pedals, slave cylinder, interior parts, etc.

What is the easiest path to working ABS, Cruise Control, and no strange electrical issues with this swap?

How is the ECU and TCU dealt with? I have seen some early swaps using an STI ECU and some others modifying the stock ECU to work with a manual transmission. I have also seen some mentions of keeping the 4EAT TCU in play for some reason. Not clear on the best approach here. I have a Cobb AccessPort if that matters.

What is a common approach related to the MT gauge cluster? Is it common to just keep the stock 4EAT cluster? How can your deal with the odometer if you do swap the gauge cluster?

Thanks in advance to anyone who takes the time to reply to me!
I think the best way would be to get a donor 04 sti that way it would solve a lot of issues involving sourcing parts also you could retain your suspension and 5x100 wheels and switch to brembos and it has all the necessary parts
as far as abs issues i used my 05 forester xt sensors with no issues and sensors. parking brake i used sti brake cables and you need the sti handbrake cable that attaches to handbrake because its shorter by just an inch but makes all the difference. The easiest way is to remember to swap everything to sti ooh and also the front cross member you you re-use the your forester im talking about the piece under the the radiator sorry im all ove rthe place i just did a 6 speed swap from start to finish myself using the forums alot of important inf was left out feel free to contact me on instagram eono808 if you have any questions.
 

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Registered
2004 Forester XT 4EAT
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38 Posts
Discussion Starter #3
Thanks for the reply. I know this is a tiresome subject so I appreciate it.

I have been doing a lot more reading and I believe I have decided to just go the full swap and do the R180 diff with the 114x5 hubs.

I just put new struts on (KYB AGX) so I'd like to keep those if I can when I do this. I'm not sure there's any way to make 02-07 WRX / 03-08 Forester / 04 STI struts mount to 05-07 knuckles or not, though some sort of safe modification.

Some of the main questions I have are:

Do you need to use the STi Subframe bits? I know Team Scream did and his is the main thread I am following but I'm not sure if he used them just because he had them or if you have to.

Is there a way for me to use my strut/spring combo with 05+ knuckles/hubs?

How do most people handle the gague cluster / odometer?

Is it possible to have Cruise control still work?
 

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Registered
05 Forester xt 6speed
Joined
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10 Posts
Thanks for the reply. I know this is a tiresome subject so I appreciate it.

I have been doing a lot more reading and I believe I have decided to just go the full swap and do the R180 diff with the 114x5 hubs.

I just put new struts on (KYB AGX) so I'd like to keep those if I can when I do this. I'm not sure there's any way to make 02-07 WRX / 03-08 Forester / 04 STI struts mount to 05-07 knuckles or not, though some sort of safe modification.

Some of the main questions I have are:

Do you need to use the STi Subframe bits? I know Team Scream did and his is the main thread I am following but I'm not sure if he used them just because he had them or if you have to.

Is there a way for me to use my strut/spring combo with 05+ knuckles/hubs?

How do most people handle the gague cluster / odometer?

Is it possible to have Cruise control still work?
As far as doing a full swap if you go with a 05- 07 sti full swap the hubs and mounting for struts are different spacing therefore you cannot use your kyb struts agx because the spacing is wrong. the 04 sti is the only year that fits the forester spacing and 5x100. the advantages of going to 05-07 sti is the bearings are physically larger and some say last longer and are able to withstand larger loads for track racing, also greater selection for rims the reason i went with 04 sti is i had a good deal on my donor car i would gladly have gone with a later year. but i like you had bought kyb agx struts also. so in short you cant mix your 05- 07 knuckles unless you purchase 5x114 suspension.
Do you need to use sti subframe bits? the easy answer is yes the only part you wont use is the front portion of the radiator lower sub frame use your forester one because the sti piece is one piece you will know what im talking about when you look at it forester is two pieces i believe. Also there is a lot of mi information out there about the cross member spacer on the foresters , when you remove them yes the eng will sit about an 1 1/4 inch or so higher into your engine bay guarantee i had to cut my tmic splitter that much to fit my intercooler so the height of the spacer will determine how much higher the engine will come up into eng bay so you will have to trim your top radiator hose too. also when you put back your subframe there will be a gap close to where lower control arm is you can bandsaw your spacer that you took out and it will be the perfect height. i recommend upgrading your steering rack to the sti and aluminum lower control arm to sti but you know that the only issue is that i think 04 sti rack and pinion fits perfect 05 and higher not sure best to upgrade steering rack bushings and all associated bushings while your in that area. also you need 2 longer bolts for subframe m12x 1.25 around 115mm hard to find i still havent.
As far as gauge and cluster my 6 speed has dccd and traded in my cluster for a jdm v9 with dccd and ceremony from aarons subie electronics on facebook he can answer all your questions and really helpful i bought a plug and play cluster harness and he reprogrammed my mileage to match original. i wanted to keep my usdm cluster but he said my 04 cluster would have a abs light on due to year so he was so cool he credited me for my cluster and paid difference for jdm cluster and harness was relly easy to install also sent him my harness for dccd and he installed it. if you wondering how i got my dccd to work i purchased a spider dccd pro kit from I wire to make my dccd function some wiring involved but super easy step by step instructions.
I hope that helps you sorry but as far as 4eat to 6speed my forester was a manual already but i just purchased a 04 fxt and planning to do an auto to 5 spd on that since i have all the parts from my 6spd swap.
good luck on your build feel free to message me on insta eono808 im in Hawaii mahalos.
 
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