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Discussion Starter #1
I have an 05 WRX wagon and need some clarification on some things.

Is the UP a design flaw? Should it be replaced with a catless version for longevity?

Does replacing the DP make the car stink? I had an RX-7 with no cats (I know it's a different extreme) and my wife couldn't be in it because of the exhaust smell.

What are the recommendations for both? Any other design flaw / problem areas?
 

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"Supreme Subaphile Extraordinairre"
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05 WRXs have cats in the uppipe. Yes, it is a good idea to use a catless uppipe. I can't vouch myself, but I have read horror stories about the cat element getting sucked up into the Turbo.

No, a DP will not make your car stink--LOL. Neither will removing all the cats.

However, before you do anything post-turbo (DP, exhaust, etc), you need an EM.

Your car has a LOT more potential than you think... but do it right, start with a good EM, and then go from there.
 

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Discussion Starter #3
By EM, do you mean a piggy back setup or a Haltech type setup? The modification order for the WRX is odd, why do you need a EM solution before the exhaust? I have the STI muffler on it...I like it, it's quiet, any real need to change it?

What type of reliable power can I make? 300? Mind you, this is a city car, parked on the street. I won't change the wheels, no front mount or anything to bring attention.

ninefourteener - you sold your 914??? rust free?
 

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Master Baiter
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By EM, do you mean a piggy back setup or a Haltech type setup? The modification order for the WRX is odd, why do you need a EM solution before the exhaust? I have the STI muffler on it...I like it, it's quiet, any real need to change it?

What type of reliable power can I make? 300? Mind you, this is a city car, parked on the street. I won't change the wheels, no front mount or anything to bring attention.

ninefourteener - you sold your 914??? rust free?
EM = engine management

There are multiple forms of this: piggyback, complete ECU swap, and flashing.

You don't really want to run exhaust on your car without EM (Catback is fine, it gives little/no performance gain). The downpipe has 2 cats in it, so if you remove those, you need to program the computer to account for it.

As for power, you can put as much as you want to spend $$. I highly doubt you could hit 300whp on the stock turbo.
 

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I have an 05 WRX wagon and need some clarification on some things.

Is the UP a design flaw? Should it be replaced with a catless version for longevity?

Does replacing the DP make the car stink? I had an RX-7 with no cats (I know it's a different extreme) and my wife couldn't be in it because of the exhaust smell.

What are the recommendations for both? Any other design flaw / problem areas?
Welcome, check the links in my sig. Even the one for bugeye owners will apply for the most part. As others have stated, the UP is a good mod to start with though engine management should be first. We don't need to use piggybacks because the factory ECU is more or less wide open. The more popular options currently are Cobb and Opensouce, less popular would be a full standalone such as Hydra, or a previously popular piggyback from TurboXS(Utec).

If you want your car to run right, you'll stay on top of engine management. There are plenty of tuning shops in the NJ/NY/MD/PA/CT area, so do some research and decide if you'd like to have one of them tune for you. You can also start reading and tune yourself if you're inclined to do so. Utec, Cobb, and XPT all have "off the shelf" maps which are generally considered safe to drive on for most cars though these maps are conservative. With a "protune" you'll be able to have more power safely, or not so safely depending on who does the tune. Research is definitely your friend. For an example, in it's present state my car made 293hp/264tq(SAE-275hp/247tq) with peak torque followed by a nasty dip around 3800-4500 rpm and AFR's around 12-10 on the Cobb vf34 map(12/1/2007), after a protune (12/22/2007) the car makes 281hp/278tq(SAE-261hp/260tq) with no more dip and AFR's around 11.5-11.3 which has made the car both safer and faster.

On the stock turbo, I don't think you'll be capable of hitting 300whp unless you go with a fairly aggressive setup tuned with meth, even then I'm not sure how long it would last as the stock turbo is going to be something like a hairdryer pushing hot air. An 18g or 20g turbo upgrade would definitely get you into the 300whp area, though you should be mindful of the trans at these power levels as more than a few of us have broken 5-speeds in our past.
 
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