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Exhuast problem + Extractors and Cold Air

PostPosted: Fri Jan 25, 2008 12:48 pm
by pplwu
Hi all,

Not sure if I posted in the right place.. please move me if you need to. I have a 3.0RB Manual and recently just done a custom exhuast system catback 2.5inch pipe and 2.5inch tips. Truth to be told I have no idea of exhuast system whats so ever. It ended up pretty good, and loud however I want the rumbling sound to come out a bit more than the muff sound (doesn't sound the wrxs). Is this a constraint on the n/a Boxer or have I not done something to get more rumbling.


Thanks guys!!

PostPosted: Fri Jan 25, 2008 12:57 pm
by tangcla
It won't sound like a WRX because the exhaust manifold is even-length on the Liberty. Unless you want to change your manifold... you won't have boxer rumble.

Exhaust

PostPosted: Fri Jan 25, 2008 1:24 pm
by pplwu
Is it? oh that shows you I have no knowledge in engine as well. SO I have no chance in hell then.

PostPosted: Fri Jan 25, 2008 1:31 pm
by tangcla
oh, I woudld't put it like that... you do have a chance, if you're willing to shell out lots of $$ for a new manifold ;)

Exhuast

PostPosted: Fri Jan 25, 2008 2:01 pm
by pplwu
Hahaha.. how much would that be? and what sort of performance benefit would I get ? thanks again

PostPosted: Fri Jan 25, 2008 2:30 pm
by tangcla
You'll probably go backwards in terms of power - even headers are supposed to give the best power gains.

I don't know how much manifolds are... depends who makes it, I guess :P

PostPosted: Fri Jan 25, 2008 11:42 pm
by MY08GT-B
The 3.0 six will never have the sound of the boxer four because of the extra 2 cylinders. The "wrx" rumble is due to the firing order of the cylinders and pulse patterns of the exhaust gases, hence why a porsche boxer 6 sounds nothing like a subaru boxer 4.

PS my 2.5 now has the "wrx" sound with the addition of a turbo back exhaust :D :D :D

PostPosted: Sat Jan 26, 2008 5:55 am
by SkoobyGT
How much are unequal length headers for the GT's?

mm no rumble, the only thing I don't like on the GT.

PostPosted: Sat Jan 26, 2008 8:08 am
by suff
Our 2L GT's use the twinscroll turbo, which needs even headers to work properly.. putting un even headers would not only reduce power (equal length headers are the best option) you will have diar effects on the spool of your turbo

PostPosted: Sat Jan 26, 2008 8:59 am
by I Wish
What rear mufflers did you install?

PostPosted: Sat Jan 26, 2008 9:01 pm
by Arith
suff wrote:Our 2L GT's use the twinscroll turbo, which needs even headers to work properly.. putting un even headers would not only reduce power (equal length headers are the best option) you will have diar effects on the spool of your turbo

Yeah, that's what I heard too. However the return to a single scroll turbo for the MY07 2.5 was supposed to bring back the rumble.
It sounds alright with the Hitech Mufflers in place. Nice deep rumble.

Mufflers

PostPosted: Sat Jan 26, 2008 9:47 pm
by pplwu
The one that I have installed doesn't have a brand its just a 2.5inch Muffler but when I get a bit more cash around I am thinking about the new STi that is posted in the 3.0RB specific forum.How much would that be?

PostPosted: Sat Jan 26, 2008 10:10 pm
by I Wish
Just be careful that the mufflers aren't too free flowing as these engines require a bit of back pressure. Otherwise it will drive like a dog,

Trust me.

Muffler problem

PostPosted: Sun Jan 27, 2008 2:10 pm
by pplwu
So what defines not too flow in a muffler? mine is a 2.5inch so is that too big.

PostPosted: Sun Jan 27, 2008 2:30 pm
by I Wish
It all depends on the internal design of the muffler. Baffles etc.

The Sti Genomes very are free flowing. Hang on to your original triangular mufflers just in case.

Is your new exhaust straight through or did you install another central muffler?