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Discussion Starter · #1 ·
I was in a shop last week when some dude had a 4" downpipe installed, which went to a 3" mid and had future plans to upgrade his turbo. I've got a 2.5" daul tip with same size midpipe and 3rd cat elim. Would I reap benifits from a 3" down pipe without leaning too much on the stock turbo, which I don't have plans to replace? If I do replace it, is the Cat in the uppipe enough for me to pass emmissions on the east coast?
 

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redwag said:
I was in a shop last week when some dude had a 4" downpipe installed, which went to a 3" mid and had future plans to upgrade his turbo. I've got a 2.5" daul tip with same size midpipe and 3rd cat elim. Would I reap benifits from a 3" down pipe without leaning too much on the stock turbo, which I don't have plans to replace? If I do replace it, is the Cat in the uppipe enough for me to pass emmissions on the east coast?
Yes, you would benefit from a larger, less restrictive downpipe. However, I don't understand what you mean by, "leaning too much on the stock turbo." If anything, you will be aiding your stock turbo by getting rid of the restrictive cats and opening up the exhaust.

If it were me, I would get rid of the cats in the uppipe and downpipe and just run one in the midpipe.
 

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If it were me, I would get rid of the cats in the uppipe and downpipe and just run one in the midpipe.
Ummm, you're lying. If it were you, you would also lose the cat in the midpipe. And then maybe throw a Prodrive can on the back end.:D
 

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cnoff said:


Ummm, you're lying. If it were you, you would also lose the cat in the midpipe. And then maybe throw a Prodrive can on the back end.:D
Well, I was speaking hypothetically for the benefit of a fellow clubwrxer who is obviously trying to "do right" by the environment and his state emissions laws by running at least one catalytic convertor. If we are truly talking about the method I would use on my own personal car, I say phuck it, lose all the cats and screw the environment, I want power!:D :D
 

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Discussion Starter · #5 ·
I guess what I menat by leaning was burning it out quicker. This car NEEDS to be with me for an extended period of time(at least while I pay it off for the extended 6 yr plan) so I'd like to free it up without a bit without risking future lifespan. ANy rec's?

SO....since i DO want to be close to passing emmisions, is the uppipe cat enough?
 

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Rumor has it that the WRX will pass a sniff test with only one cat in place. However, to truly tap the power potential of the WRX you would be best to remove the cats in the up and downpipe and keep a cat in the midpipe. It will allow your turbo to spool up quicker and allow your engine to breathe better. The most obvious way to decrease the life of you turbo is by cranking up the boost to unreasonable levels and hammer the car to redline every shift. An exhaust upgrade will not stress your turbo, your simply "freeing up" horsepower.
 

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Discussion Starter · #7 ·
Thanks flyboy!

It sounds like the downpipe should go next. What exact is an uppipe? I asked my buddy who's pretty informed about cars and he's never heard of oone. He's got a hooked A4 Pulleys don't seem like a good idea for longevity, and I've got a stage 1 unichip w/ xgass setting for a CAI, so what's your impression on my next step?
Should I turn the boost down Just a little bit on my mbc and by doing that, do I gain anything in the low end? In case you were wondering, I don't really know SH#T about much, so any help is weelcome. People have also told me to dump my SOA warrenty to 100K, but I can't do it. I've got all my stock stuff just in case, ya know? Any help for my dumbd @ss is more than welcome. Thanks all

Mike
 

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redwag said:
Thanks flyboy!

It sounds like the downpipe should go next. What exact is an uppipe? I asked my buddy who's pretty informed about cars and he's never heard of oone. He's got a hooked A4 Pulleys don't seem like a good idea for longevity, and I've got a stage 1 unichip w/ xgass setting for a CAI, so what's your impression on my next step?
Should I turn the boost down Just a little bit on my mbc and by doing that, do I gain anything in the low end? In case you were wondering, I don't really know SH#T about much, so any help is weelcome. People have also told me to dump my SOA warrenty to 100K, but I can't do it. I've got all my stock stuff just in case, ya know? Any help for my dumbd @ss is more than welcome. Thanks all

Mike
The uppipe is between your passenger side exhaust manifold and your turbo, you can not see it by looking under the hood, it is concealed by the engine and underneath it is concealed by a heat shield. It contains a catalytic convertor that is very restrictive. Eliminating this cat improves turbo spool up and exhaust flow. Pullies are good for low end torque and won't harm the longevity of your engine, again, your just freeing up horsepower within the engine.

Lowering the setting on your MBC won't gain you anything on the low end.

As far as your extended warranty, that's your choice. I bought my WRX so I could mod it and don't give a damn about my warranty, I'll cross that bridge when I come to it.

Get your exhaust completed first, then get your Unichip remapped for Stage II.

Don't worry, six months ago I didn't know jack about this car either. Just keep reading the posts on this forum, there are some very helpful people here. :)
 

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Discussion Starter · #9 ·
so the next logical question is which one first?
an Uppipe or downpipe? since my exhaust is 2.5" all the way,
should a 3" downpipe be what I'm looking for?
 
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