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MY09 2.5i - Uneven headers and/or catback exhaust?? - Sydney

PostPosted: Sat Jul 23, 2011 12:53 am
by garthos
Hey Guys,

I know this topic has come up a few times, but after searching through many on topic posts, I'm still a little unsure of which way to go.... hoping someone can give me some advice :?:

Firstly, my ride is a MY09 2.5i, stock apart from the grille, canons and 19" RS GTs.

While I've been happy with the note and look that came from swapping out the stock mufflers with the canons (Liverpool Exhaust), I'm now looking for a louder and (hopefully) boxier tone. Understanding that swapping out the EL headers for UEL will not improve performance, Im wondering if the addition of a catback exhaust might instead give me the better sound with better performance without the need for new headers?

Also the issue has been raised that custom fitting/headers are needed for the UEL headers for MY09 2.5i, can anyone confirm whether there is anything that will fit this as standard or where to source custom headers?

I have also seen it mentioned in other posts, the removal of the centre muffler/resonator might open up the sound and flow of the exhaust?

Any input would be appreciated, I'm in the Sydney region.

Many Thanks,

Garth0s

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sat Jul 23, 2011 10:34 am
by Dropz
From my knowledge 04-06 had el headers and 07-09 had uel, not 100% sure though. Removing the centre muffle will make a big difference. If you want that 'suby rumble' the best way would be to get a catback exhaust. Something like 3 inch through to your mufflers.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sat Jul 23, 2011 8:55 pm
by garthos
Just double checked the specs and MY09 definately has EL headers. I think I will head over to Liverpool Exhaust next week and have a chat to the guys about fitting a catback exhaust and see how it goes from there. I can always swap out the headers at a later stage if I want more rumble. 3" sounds pretty good :)

Sorry to have to ask another beginners question, but with the addition of a full catback exhaust, what happens to the centre muffler/resonator? Is this replaced with straight through piping or does it include a new centre muffler/resonator, or is that optional depending on the design of the catback?

Thanks again, any feedback is welcome.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sat Jul 23, 2011 11:39 pm
by Dropz
It'll be optional. Some places to kits for popular cars like skylines and wrxs, but normally people would get a custom exhaust made to their specs for size, sound, look, etc.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 1:42 am
by tkboi
you wont get the subaru burble with a catback exahust system, the only way to get it is changing your headers, you will get the burble note on idle thats pretty much it haha. trust me i know =(, headers is too expensive so i prob wont chase it later down the track

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 9:10 am
by Dropz
Look for headers On eBay or import monster if it's that important. You can get it with catbacks, I've seen a few.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 9:54 am
by cruisn
On a previous NA Subaru I owned, I did the full catback and got a very mild "burble". Once I put Borla style UEL headers on it, hello boxer note. Sounded like a full on WRX. On a side note, I did find that with just a catback and no centre pipe resonator I had no burble at all, but with a hotdog added to the centre I had a mild burble.

Image

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 2:02 pm
by tkboi
thats correct but for post facelift models for some damn reason apparently theres too much sensors or something and the borla replica headers do not fit there somehow different compared to the preface lift model, but if you got a prefacelift model you can buy those headers and they fit straight on, correct me if i am wrong but this is what i got told by many haha

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 4:12 pm
by cruisn
Im sure if you "really" wanted to do it you could just get some made up.

But on an NA, just for the sound, it'd be a costly exercise.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 4:25 pm
by Dropz
Yeah post facelift has different cat and o2 sensor Positions.

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Sun Jul 24, 2011 4:43 pm
by tkboi
getting custom UEL headers made up to lose performance is what i said to myself and i was like... "really the N/A is pretty damn weak already" so i screwed that option haha, i think i got quoted 500+ for custom made UEL due to the post face llft headers were all over the place or some crap so they charged a fortune for labour as well

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Mon Jul 25, 2011 12:54 pm
by black_2.5
That subaru rumble is from the un-equal length headers.

Putting a cat-back and removing resonators wont give you that exact rumble a wrx gets, but it will still sound nice! No arguments there.

Theres tons of vids on youtube if you want to see how a liberty sounds with UEL headers.

As for the performance, you have to compare apples with apples. When the wrx boys put on EL headers and get more performance, they aren't bolting on the stock EL headers from liberty's, they are bolting on aftermarket more free-flowing headers. So yeah, EL headers can give more performance that UEL.

But when you are looking at stock vs stock, the difference is minimal. I got this from other forums. And remember we are NA, so if theres minimal difference when turbo'd then there will be even less difference when the car is NA.

Heres a link for installation of UEL headers on a 2.5i. (sorry for linking to a different forum)

http://forums.nasioc.com/forums/showthr ... ?t=1445402

my $0.02

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Mon Jul 25, 2011 4:16 pm
by garthos
Thanks for all the feedback guys, some interesting and useful info for sure. I think I'll stick with the Catback for now, it seems less complicated than swapping out the headers.

I'll post an update once I have some more news!

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Tue Jul 26, 2011 8:50 pm
by garthos
Ok, so I went and had a chat to Shev today and he gave me a pretty reasonable quote for a 2.5" from cat to Y pipe. When asked how loud I wanted it, I went for the loud but not ridiculous loud... but later kicked myself as I realised that I should be getting the full exhaust cat to mufflers, this is probably why he quoted me for cat to Y pipe?

Apologies for more beginner questions..... but if going from 2.5" from Cat to Y pipe, then back to stock Y pipe and through to Canon mufflers, wouldn't this still be a little restrictive when going through the stock Y pipe? Shouldn't I just be going for the full cat to muffler exhaust?

Also, what differences if any, could I expect on a NA when comparing a full 2.5" cat to mufflers with a full 3"? As per 'Dropz' recomendation should I be going for the 3" instead of 2.5"?

Re: MY09 2.5i - Uneven headers and/or catback exhaust?? - Sy

PostPosted: Tue Jul 26, 2011 9:29 pm
by Dropz
3 would have a deeper note, 2.5 will be pretty quiet, and unless you upgrade the mufflers it'll have little to no desirable effect.