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Discussion Starter #1
the search continues, as i'm sure it does with most of you guys too, for mods for the car.
i currently live in mass, but have no idea on emissions req, and am getting ready to move in about a month or so.... to where? not sure.
i am a bit concerned about the legalities of removing all cats, as well as how far i can go mod-wise before a hi-flo cat really restricts me.

from what i can see my choices are:
turboxs: don't like how it necks down continuously from 4" to almost 2.5" at the muffler
gpmoto: don't know what type of cat they use, but have heard from a couple sources that is not perfect in the fitment dept.
xxceleration.com exhaust: has 2 small hi flo substrate cats i believe, but i haven't heard much good about this company.
stromung: leading candidate right now. uses a metal substrate cat in a secondary pipe behind the dp. i have been told this type of cat is superior in flow, durability, and max hp allowed vs. conventional cats

how limiting is a hi-flow cat in terms of future mods like a bigger turbo and all that it entails?


hmmm, maybe i don't have to worry about this if i just buy the race pipe as well, and keep it on standby? :wink:

i guess my problem is one side of me i saying to just do basic mods as this car is still the fastest i have ever owned, and my driving is still limited by pesky speed limits.
whereas, the dark side tells me to go big or go kia!
 

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FS: STi Front and Rear seats ($1k)

the trick is to hang on to your catted factory unit....have it re-installed for emissions and then have your cat-free down pipe re-installed.I know it's a big leap(going cat-less) as well as the risk (cops). i'm in r.i. and i havent had a cop go under my car in 20 years of driving. they ask me to pop the hood before but no prob on the exhaust. mod up...it's almost time to play 8) N.E. Dragway.............11 sec here i come!
 

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Wow...lots of snow **edit-pics added**

You still have more choices... heres your best bet. For down pipe (catless) is the godspeed downpipe. Its clears the wastegate flapper and flows plenty enough and is a perfect fit. NO CEL. For catback, that is up to you. I love the blitz, but I could care less about that 1hp-2hp i might have if i was to go with another company (as an exhaust is all about sound anyways). If you want a high flow cat, maybe buy a high flow cat mid pipe? Random technology even has cats that are almost 100% free flow (Catalysts-look like oval cans)!!! Trust me man, if you want high flow and still pass emissions.. it might take a little extra effort, but Im sure RT or someone out there will have a setup for you. Good Luck!

Robert~
 

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salisburyv said:
the trick is to hang on to your catted factory unit....have it re-installed for emissions and then have your cat-free down pipe re-installed.I know it's a big leap(going cat-less) as well as the risk (cops). i'm in r.i. and i havent had a cop go under my car in 20 years of driving. they ask me to pop the hood before but no prob on the exhaust. mod up...it's almost time to play 8) N.E. Dragway.............11 sec here i come!
Yep,,same fr me. except i keep the dowqnpipe in and still pass emissions(Md.)
Rudy
 

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Discussion Starter #6
as it turns out,
xcceleration.com uses random tech's new metal substrate cats in their exhaust. they are listed on random's site as a dealer, and the only subie one at that.
stromung's cats are a metal substrate as well, and look almost identical to the random tech's but the gentleman @ stromung would only go so far as to say they have them made for them by a 3rd party.
stromung uses one cat, the xcceleration uses 2.
i also inquired about the zerosports exhaust from japan. it seems to use some form of metal cat in it, and from the pics it looks to be a top quality piece. the only hard part is finding someone who can get them for less than an arm and a leg.
 

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why not go custom and just use a generic 3" high flow cat? Those are really cheap and a good muffler shop can make you a catback for much less than these pre-made systems. Just buy the catless downpipe you want, get a generic high flow cat and have a true 3" system welded up.

I did it with my friends shop (no labor charge) and the parts cost me just under $225 not including the downpipe.
 

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Has anyone replaced the pipe just after the downpipe with a straight pipe, removing one of the cats?

Can you comment on any of the gains?

~nivek
 

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Check out the latest issue of TUner Performance Reports (TPR) they dynoed a Random Technologies cat versus a catless exhaust and the difference was only 1 horsepower, very nominal and you won't go through the hassle of tickets/fines, or reinstalling all the stock stuff for emissions testing.
 

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I am running catless all the way! The down side is that things are a little louder. I have had a huge improvement in hp gains but I pretty much did the dp, secondary, midpipe all at one time. So it is hard to say what really made the biggest difference. The other issue is the smell that you will get. I have checked they system and seem to have no leaks but you can really smell the exhaust now! At idle it seems to creep into the car but once rolling it is normal.
It is cheaper to run catless however which is why I did it. However, even though I have the stock cat I will probably buy a hi flow version when the time comes. You can check out my sound clip listed on here in the mods section if you want an idea of what a full/catless exhaust will sound like on your car.
 

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DRNWAGN

There must be a leak somewhere. Simply dumping the cat will NOT cause an increase in in-car exhaust fumes.

A good way to check is to put the car on a hoist with it running and use a towel or shop rag to completely cover the exhaust tip so there is NO leakage. Then, have a partner in crime walk the exhaust and find your leak.

-Sporty
 
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