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2002 WRX
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136 Posts
Discussion Starter #1
I'm looking at what it would take to bump my (power wise) stock '04 FXT (4EAT) up a few notches in terms of power. Mainly looking for more punch from the throttle and a wider power band to offset the automatic gearing. I'm thinking Cobb Stage 2 with an OTS map is about the most economical way to get where I'm going.

So, questions:
1) Am I correct in my understanding that all I really need is a catted downpipe (I'd get the Cobb one with the wide mouth) and an Accessport with OTS Stage 2 map?

2) Is there much else to gain from also doing the full 3" TBE with the stock turbo?

3) Other than the reliability improvement, is the much to gain from a catless up-pipe with the stock turbo and OTS Stage 2?

4) Is there any point in doing the STi TMIC with this setup?

5) Has anyone with significant mileage and a similar setup to what I'm describing had any reliability issues or concerns? This is my daily driver and I want to have a 300k mile Subaru somewhere down the road.
 

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2005 Forester XT 4eat
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4,583 Posts
1) Yes

2) Slightly more torque and more hp through the rpm range; nice exhaust sound

3) Quicker throttle response and slightly more torque / hp

4) The stock TMIC is very small and restrictive. STI TMIC won't make a huge difference with the OTS map, but can make a difference.

Some people have been very happy with just changing out the DP and installing a stage 2 map. IMO, if you are on a tight budget, it's the best bang for the buck for a stage 2.
 

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2004 XT
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3,203 Posts
I'm looking at what it would take to bump my (power wise) stock '04 FXT (4EAT) up a few notches in terms of power. Mainly looking for more punch from the throttle and a wider power band to offset the automatic gearing. I'm thinking Cobb Stage 2 with an OTS map is about the most economical way to get where I'm going.

So, questions:
1) Am I correct in my understanding that all I really need is a catted downpipe (I'd get the Cobb one with the wide mouth) and an Accessport with OTS Stage 2 map?

2) Is there much else to gain from also doing the full 3" TBE with the stock turbo?

3) Other than the reliability improvement, is the much to gain from a catless up-pipe with the stock turbo and OTS Stage 2?

4) Is there any point in doing the STi TMIC with this setup?

5) Has anyone with significant mileage and a similar setup to what I'm describing had any reliability issues or concerns? This is my daily driver and I want to have a 300k mile Subaru somewhere down the road.
depending on where you are this is the easiest not the cheapest as there are open source tuners out there that can and will give you a better tune than a OTS accessport tune and for right around if not less than the AP costs. I would also at the same time see if you can find an sti catback(3in exhaust not necessary) to go with the downpipe, catless uppipe is required. intercooler though not requires with this set up never hurts.

on my first xt i had 94k miles and i ran cobb ots stage 2 with a helix dp, hks catless up, and sti catback with no issues whatsoever

how to go faster than sti for cheap answers most of your questions, so definitely refer back to it.
 

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2004 fxt A/T
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2,567 Posts
I don't know how much of a budget you are on but you could do an STI swap for the same money or less.
vfxx-$300
STI TMIC-$300
shorty DP-$150
tactrix 2.0-$160
etune-$150
Grand Total=$1060

Cobb DP-$595
Cobb AP-$595
Grand Total=$1190

Oh and the catless uppipe isn't optional, I would take it out before doing anything.
 

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Premium Member
2008 FSXT 4EAT
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4,143 Posts
1) Am I correct in my understanding that all I really need is a catted downpipe (I'd get the Cobb one with the wide mouth) and an Accessport with OTS Stage 2 map?

An AccessPort is not needed, if you can find a tuner who can opensource protune your vehicle. A protune is going to be ~$300-400. The downpipe does not need to be catted, but your county/state may have specific emissions requirements.

2) Is there much else to gain from also doing the full 3" TBE with the stock turbo?

From what I've seen/heard a 10-15 hp gain can be expected from a full TBE exhaust.

3) Other than the reliability improvement, is the much to gain from a catless up-pipe with the stock turbo and OTS Stage 2?

The reason people de-cat the up-pipe it to prevent it from breaking up and damaging the turbo. The 04/05 FXTs have catted up-pipes, whereas the 06+ FXTs have no cat in the up-pipe.

4) Is there any point in doing the STi TMIC with this setup?

It certainly helps to cool the charge before entering the intake manifold, and they're relatively cheap and easy to install.

5) Has anyone with significant mileage and a similar setup to what I'm describing had any reliability issues or concerns? This is my daily driver and I want to have a 300k mile Subaru somewhere down the road.
I was Cobb Stg II for a while, and to be honest, it isn't that great after a while. My car suffered from wastegate flutter, which is caused by inadequate resistance by the TD04's internal wastegate. The turbo is creating more pressure than the stock wastegate it built for, and the WG flaps back and forth during load, when it should stay closed. This makes the car sound like a loud sewing machine, and it causes the car to surge under moderate throttle. You can manually tighten the wastegate arm to increase the resistance, but I don't think it'll entirely eliminate the problem.

Since you're on a budget, I recommend the following:

***Used downpipe - Catted ($300), catless (<$200)
***Used STi TMIC - <$300
***STi Up-pipe - <$80 (or decat your own)
***Used VF39 - <$300
***Opensource protune - $300-400

***TOTAL - $800 - 1380
 

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Premium Member
2007 Forester XT 4EAT-VTD
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2,138 Posts
I'm looking at what it would take to bump my (power wise) stock '04 FXT (4EAT) up a few notches in terms of power. Mainly looking for more punch from the throttle and a wider power band to offset the automatic gearing.
That's what I said too.

Good advice above, to which I would like to add the following - whatever you buy now, buy it now so that you don't have to buy it again should you want to go further.

Get an exhaust that will be adequate for a larger turbo. I use the MadDad catted bellmouth DP and 3-inch Whisper cat-back. It will work well on your car now and later if you upgrade the turbo.

Upgrading to a STi TMIC is not a bad investment - they can be had for about $300.

Once you do that, go find an open source tuner. The shop I used changed my grandma-shifting 4EAT into something much better (and of course, they wrung out all the ponies to be had).

Start with those three items - a full turbo-back exhaust, a STi TMIC and a open source tune and you'll be good to go. Upgrading to a used VFxx turbo will only cost you $300 to $500 more and will more than double-the-pleasure of the results of the first 3 mods above.
 

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2005 Forester XT 4eat
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4,583 Posts
More food for thought here. Based on a lot of what I've seen on this forum, 4EAT XTs benefit the most from mid size (VFxx, TD05, etc.) turbos. Stage 2 just gives you a bump right around where the torque converter stall happens. It might be good for a laugh or two playing stoplight drag racer, but the way the auto shifts under full throttle, a lot of time is spent between 4500 and 6000 rpm under full throttle where the TD04 just falls flat on its face.
 

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2002 WRX
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136 Posts
Discussion Starter #11
I really appreciate all the info on how economical a turbo swap and open source tune would be, and I'd really love to go that route. Problem is, I'm not very mechanically inclined. When I mess with my car, things tend to go wrong or break... even if they're not related to what I did.

I think the nearest reputable open source tuner is about 200 miles away. So the best scenario I see for a turbo swap is to take a field trip there, and pay then to install all these mods and do a tune. That's getting costly in both time and money.

On the other hand, I can handle a downpipe install and button pushing on an Accessport myself. So I could do my upgrade on a Saturday morning in my garage, rather than needing a 2 day trip, and if the claims of ~75hp and a taller, flatter torque curve are true, I think I should be happy with it.

Still though, if I absolutely have to do the up-pipe (not sure I'm up for DIY when un-bolting the engine is required) and I'm going to have to battle with wastegate flutter (unreliability kills the whole point of staying close to stock), maybe basic Stage 2 isn't the easy way out after all.

Guess I could just do Stage 1, but I doubt I'd be happy with that. If I'm getting into power mods, I'm going to want to get a very apparent impact out of it.

Maybe I'm better off to just leave well enough alone.
 

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2004 fxt A/T
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2,567 Posts
More food for thought here. Based on a lot of what I've seen on this forum, 4EAT XTs benefit the most from mid size (VFxx, TD05, etc.) turbos. Stage 2 just gives you a bump right around where the torque converter stall happens. It might be good for a laugh or two playing stoplight drag racer, but the way the auto shifts under full throttle, a lot of time is spent between 4500 and 6000 rpm under full throttle where the TD04 just falls flat on its face.
I couldn't agree more, I just finished up my vf43/08 TMIC swap last week and after driving it for a while I love it. You might be thinking "I don't need that much power", but it is more to do with how much smoother the car feels now. I am only currently running 13 psi (I know I know it is going up this week been busy) and the car feels like stock but quicker and smoother. Before the Foz was a BEAST in first gear but after the first shift it made a lot of noise and that was about it. Now it is quicker but not that punch you in the chest feeling from the small TD04 hot side. Have you ever been at a packed concert and the whole crowd surges forward? That is the closest I can describe it, just power pushing in a constant wave.
 

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2004 fxt A/T
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and if the claims of ~75hp and a taller, flatter torque curve are true, I think I should be happy with it.
It definitely won't be flatter, your peak torque will just be higher at the same point and then fall off just as fast. I'm pretty sure the Cobb OTS maps just change the WGDC table and nothing else. Translation, higher boost but the same crappy overly rich AFR's.
 

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Premium Member
2017 VW Golf SportWagen 5MT
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10,786 Posts
I ask what your budget is because Stage 2 is doable cheap-ish, or you can buy parts that will allow you to "grow" your setup later. To do it cheap, you could pick up a used downpipe ($150 catless or $300 catted) and a used AP ($300), OR do an opensource tune ($300?). Either way, I'd budget at least $600.

You don't need a 3" exhaust, you'll gain nothing but noise. I will be taking off the 3" catback as soon as I get the car retuned -- I'm running a VF43. Stage 2 map will absolutely NOT give you a 75HP gain anywhere and it won't flatten out your curve -- it'll probably do the opposite, making your car less smooth to drive.

Stan
 

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The Sub kit guy
2005 Forester X & XT VF39
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13,008 Posts
Since you have an 04, look for an AP v1. I see them as cheap as $150.

I personal run a VF39 with a stock midpipe and an STi exhaust and I still make over 100hp more than stock. I skipped stage 2 because the cars I drove setup that way were not fun to drive. Way to peaky and "raw" feeling. You have a very small power curve that hit really hard, but for a really short amount of revs then it falls off hard. The TD04 is a horrible match for the stock shift points in the AT too. On downsifts it wants to run the revs higher than where the TD04 sweet spot is. A VFxx turbo fits those points much better.
 

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2002 WRX
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136 Posts
Discussion Starter #16
Stage 2 map will absolutely NOT give you a 75HP gain anywhere and it won't flatten out your curve -- it'll probably do the opposite, making your car less smooth to drive.
That kills it then. I'm definitely not looking for more of what I already have. I actually enjoyed the peakiness in my 2.0L WRX... like a dirt bike power band. But that just doesn't work with an automatic. Thanks for saving me some disappointment, everybody.

As far as budget, I don't really have one at all. I'm more just investigating my options and planning my savings... then deciding if the timeline for saving enough to drop on upgrades is worthwhile for the impact the upgrades would make. Stage 2 on the cheap side seemed like it would be good impact for the length of time it would take me to save and non-majorness of the work to be done. When you start talking about whole turbo system swaps and custom tuning, things quickly go from simple performance boost to major work... and it gets unjustifiable for me. I'd love to have the whole vf39 package, but I just can't see myself ever going through such an extensive upgrade. So as good of an idea as future-proofing would be, I highly doubt I'd ever go further than what can be had with simple mods.
 

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The Sub kit guy
2005 Forester X & XT VF39
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13,008 Posts
I was seeking the same things you were when I got my XT, and swapping the turbo made sense. First thing you need to get rid of is that catted uppipe. To do that though you have to remove the downpipe, so you might as well replace that too. With both those out, the turbo is basically out, so it makes sense to upgrade that to a VFxx while you have it all apart. The parts are pretty cheap, so it doesn't take long to find good deals and piece them all together.

Swap those 3 items, add an STi TMIC and a AP v1 and your all set. You can do it for under $1000 to if you are patient and shop for deals.
 

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2004 fxt A/T
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2,567 Posts
Since you have an 04, look for an AP v1. I see them as cheap as $150.
AP V1's for 04xt A/T are getting to be a pretty rare birds, I looked for one for a while before deciding on Opensource.
 

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2002 WRX
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136 Posts
Discussion Starter #19
After some more consideration, I've revised my thinking on how to proceed.

New goal: Just widen the power band a little to prevent dropping completely out of boost on the 1-2 shift at moderate throttle... and in general compensate for the 4EAT's lousy shifting decisions. After thinking about it, I'm pretty happy with my car when it's behaving, and downright thrilled when conditions are just right and it pulls crazy hard. I just want to make that feeling more consistent. Then somewhere down the road I'll probably get a hatchback WRX with a 5-speed anyway.

So I'm thinking again that maybe a turbo swap isn't needed right now, but maybe I should get the catless up-pipe done while I'm having my timing belt replaced. No tune on that, right? Plus protects my turbo and supposedly improves spooling and throttle response... any truth to that?

Then I could add a down-pipe and open source protune later, when my budget permits. Maybe this gets me a smooth and wide-enough power band for good feel and drivability, and I just accept the top end for what it is.

Still further down the road, like has been suggested, I'd be set up for a bigger turbo and TMIC if I wanted. But that's $600+ that I don't have to spend if the down-pipe and tune makes me happy.

Keeping in mind that I've moderated my expectations, am I setting myself up for disappointment at any of the steps on this plan?
 

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Premium Member
2017 VW Golf SportWagen 5MT
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10,786 Posts
Uppipe sounds reasonable. I'll just add that if you are planning on upgrading the turbo in the future anyway, just shelf the parts and do turbo and downpipe all at once -- that way you won't have to pay for a retune and save some money that way.

Stan
 
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