Sti cat back

[4n70n1n0]

I did a search and if you ever used the search engine here its not so great.

I looked thru 3 pages of the Swap & Conversions forum and nothing yet, so ...

Im looking into picking up a sti cat back later this week. Other then move hangers and i believe also extend the piping, wht do I need to do?

Reason behind this is because I've gotten pulled over twice already for my exhaust and after a total of 450 dollars on exhaust fines alone. I've had it with my cat back.

**I will be putting my custom one piece cat back for sale one the sti cat back is installed

Thanks,
-Ant

[Huffer]

Ant, you could just install a resonator in the midpipe of your custom exhaust to cut down on the noise.

But, I have an STi "catback" - it's actually just a custom midpipe w/ an STi axle back bolt up. Had to relocate a hanger and rotate the end flange.

https://sl-i.net/FORUM/images/imported/2009/05/STiaxlebackmidpipe0-1.jpg
https://sl-i.net/FORUM/images/imported/2009/05/STiaxlebackmidpipe1-1.jpg

[4n70n1n0]

Hey Roger,
I have a resinator, but i also have a test pipe :), plus I was actually going for a whole new exhaust look since my muffler has a 4.5 inch tip on it. I guess I can't use the whole cat back from the STi :(

OK, looks like I'ma just cut my muffler off and put the STi muffler on

THANKS

P.S.: I'm still going see prop my car on the ramps and slide under there with the STi cat back to see how much work is needed just out of curiosity, ya know

[Huffer]

The major issue is going to be the axleback then - if you already have a resonator. That's where the majority of the noise is coming from.

The STi catback isn't really going to be useful because it has a cat in the midpipe already, and the bends are slightly different. I had one once and IMHO it wasn't worth it to "make" it work. Going one-off custom with a good shop was a lot cheaper and fit better in the long run.

[4n70n1n0]

yup I was just looking over the pics of the cat back and at cat back and ur right

Ima just going to cut the muffler off and have my exhaust shop weld it in place of my current muffler

THANKS

[Huffer]

You're welcome. I'll PM you my paypal address for tips.

:P J/K. :D

[impreza_GC8]

The major issue is going to be the axleback then - if you already have a resonator. That's where the majority of the noise is coming from.

The STi catback isn't really going to be useful because it has a cat in the midpipe already, and the bends are slightly different. I had one once and IMHO it wasn't worth it to "make" it work. Going one-off custom with a good shop was a lot cheaper and fit better in the long run.

This is a common misconception, it isn't a catalytic converter in the midpipe, its a resonator. It looks like a cat because its funky shaped but its not.

[Huffer]

Ehh, the one I had from a 2005 STi I sliced open and it was honeycombed like a cat. Cat, resonator, still a sound-deadener.

[impreza_GC8]

A cat will have a lot more junk in it than just a honeycomb pattern. I removed the resonator as well in my '05 STI setup, didn't cut it apart but I know its not a cat, those are in the downpipe on an STI. I suppose in the uppipe for some years as well.

[Huffer]

Regardless, it's junk in this application. :)

[driftskeetka24e]

i put a wrx midpipe on my 92 legacy wagon just had to twist a flange.(friend only kept the mid pipe so havent gotten an axle back yet)

but on the axle back...
are the sedans different from the wagons?
and bug eyes different from newer wrxs?

basically had an 05 wrx axle back and decided not to do it because how far off the hangers are from stock location and wondering if the bug eye wagon or just bug eye hanger set up is different?

thanks guys

[Huffer]

Honestly, the STi/WRX axlebacks are pretty heavy. If I did it over I would probably go with a smaller, lighter canister with the same diameter tip.

There are slight differences sedan vs. wagon. The one I have (in the pics above) is from a sedan, so it's tucked up under my bumper more, which I like.

Don't be scared off by hanger relocation. It's simply cutting and welding. Any decent exhaust shop can do it in an hour.

[wrxya33]

A cat will have a lot more junk in it than just a honeycomb pattern. I removed the resonator as well in my '05 STI setup, didn't cut it apart but I know its not a cat, those are in the downpipe on an STI. I suppose in the uppipe for some years as well.

Just a note sti's never had a cat in the uppipe at least not in the us. They are only in wrx's and its retarted because god forbid a piece of it chips off instant blown turbo.

[prodriver1]

i have a 04 wrx muffler and custom 2.25" piping and it sounds great! i have a stage 2 wrx header and im thinking of getting more 2.25" piping to replace the cats but not before some more engine upgrades.

[prodriver1]

DONE! i have full piping now to the wrx muffler (which will blow out soon from the pressure) very rumbly:)