Ok, I might be coming up on a factory 2005 STi catback for a great price. I read the whole thread and searched. Anybody know if the stock catback for an STi will bolt up to my 2005 2.5RS? Also is it really that much better? I don't know what the stock STi pipe size is or if the muffler is free-flowing or what.

If I don't put on the STi catback, I'm just gonna get some mandrel bends and have a 2.25" or 2.5" catback built using a magnaflow muffler and resonator... Thanks guys...

-Ryan-

 

what kind of kw/hp gains are achieved with a whole new exhaust system?

 

Not sure if you ever got your answer elsewhere, but yes, it will bolt right up. I asked the same question (on RS25.com) as I was in the same situation. As for the diameter of the pipe...not certain.

Good luck.

 

Newbee question, I have an RS 05 and like almost everybody, whould like the turbo boxer sound. I've read on forums that even replica borla headers would do the job even those unequal length headers sold on ebay is this true? What other exhusts mods required to atain this?
Would the header below enough to achieve this? Any info is greatly appreciated.

 

anyone tried the USDM or JDM genome on their RS?

 

I was wondering the same about the ebay headers?

I heard from some that the ebay ones are actually contructed better than the borlas.

 

I've read alot of people that complain about borla's (just like people complaining about K&N air filters) tho I don't think personally i'd feel safe with just a cheap ebay header. without some kinda decent lenght warrentee

 

Im running stock headers (borlas cracked beyond repair) random tech cat and xcelleration 3inch catback. its really really loud

 

Its loud becasue of your cat...

I dont want to spend that much on a cat though, plus isnt that annoying having to take it off for emmisions.

Someone said the ebay hears actually last unlike the borlas.

 

They can be found used. I just sold an RT cat pipe for $175 (single cat) and gave away my Swain Coated and re-welded Borla header.

 

You mean the random tech will pass emmisions or what do you mean?

 

You said: "I don't want to spend that much on a cat though..."

Then I said: "They can be found used. I just sold an RT cat pipe for $175 (single cat)..."


Make sense?

I don't know if it will pass emissions, but I assume it will otherwise WTF would be the point? Worst case, I have had several cats installed at muffler shops that did pass emissions over the years, so you could get a catless pipe really cheap, and have a shop weld in a new cat on it. You would not have spent as much as a new one, you would be passing emissions, and you would have MUCH better flow than the stock cat system...

 

Well I was actually lookignat the stromung one which is a little cheaper... but I havent decided on it yet.

 

That's what I was going to get until I saw this one for sale. I don't see a major difference between the two except that the Stromung looks like a proper cat where the RT is a friggin strange melon sized thing. My only thought with the RT was the cat is closer (forward) to the engine, so it might have less of the 'cat light-off' problems that result in sensor in-efficiency CELs. But... I got CELs with mine, so WTF.

If I were gonna do it again, I would either get a Stromung or a catless pipe and have someone weld in a new cat.

 

Thanks for the advice... I cant wait for my spt to comine in though, I just hope it sounds good.

I have a weapon-r intake too so that may help a little bit.