Exhaust notes...

[HOSTILE]

Hey fam, I just got myself an 07 liberty spec b tuned by sti. Stock standard. Absolutely love it!!

I have no desire to modify her as I think she's perfect, but I wouldn't mind a bit more grunt from the exhaust..

What are some of your thoughts on a resonator delete and adding a straight pipe?

Would it affect anything in a negative way?
All I'm looking for is that awesome sound of the boxer.

Any advice would be greatly appreciated, cheers!

[Stifull]

I did a res delete on mine and it made no difference at all to performance and sound. I added a cat back 3" Xforce exhaust and it made a big difference to the sound and a little to performance.. Sounds sooo much better. Actually sounds like a turbo Subaru should..It was almost new and cost $300 and took half an hour to install..The seller bought the system and then got a different turbo and down pipe and it would no longer fit so he flogged it off on gumtree...

[HOSTILE]

Hey man, thanks for your reply!
Okay it sounds like you know your Subies due to the list of family vehicles haha thats awesome!

I'm new to this so excuse my stupid questions lol
So no difference in sound at all with the res deleted??
I saw a few YouTube videos of guys doing it and it made a slight difference..

But ok, since all I'm after is a slightly louder note nothing crazy. What would you recommend?
Also did your GT require tuning just with the cat back or did you have other mods at that time?

[HOSTILE]

So I can keep the stock tail pipes and a slightly louder note what would you recommend?
I dont want to play with the boost at this point as shes my daily driver and dont want to break things lol

[Stifull]

The Xforce is cat back and includes mufflers so it is the complete system from the cat to the back..
New....

Old....


On the wrxs removing the resonator make a big difference to the intake suction noise..It was one of the first things I did to my GC8 when I got it. It now has a CAI with a pod filter in the front guard and that gives the same induction noise as removing the resonator. The Libs must have a different system because removing the resonator seemed to make no difference. Could be that the bigger turbos on our other cars suck more air. Also, remember you can't do major mods like changing turbo or big changes to boost or turbo back exhaust or divorced or bellmouth down pipes without getting a tune.....Tuning will cost $1000 approx, so, if you plan of moding for performance you should get everything together, turbo, downpipes, exhaust, injectors, CAI, silicon intake piping etc etc , get them all fitted at once and get a tune ASAP and DON'T drive it hard till it's tuned or you blow something up...Changing the exhaust from the cat back is about all you can do safely. It's definitely worth doing just for the better sound.

[HOSTILE]

Roger that!
Thanks for your reply mate, I appreciate your time on the subject.
I am aware of having to get the tune once adding an intake, Down pipe etc.. Definitely dont want to go down that route with this car.
If I got the xforce cat back, would I be able to keep the stock sti tail pipes?
I know it would silence the note a bit, but I'd be happy with that.. Just a slight rumble would be great. I really want to keep her looking original..

[Stifull]

I'm sorry but I am very new to the Liberties.. You can't swap the small tailpipes on the xforce but there may be others that will allow you to do this. It's the new mufflers and larger diameter pipes that increase the rumble. If your Sti mufflers have a removable end tail pipe you may be able to slide them over something else as long as they are big enough. The tail pipe on the xforce are almost 100mm.

[HOSTILE]

Thanks for the heads up mate!
Drive safe.

[bigBADbenny]

Bit of a tough call without a tune, or monitoring the current tune with Romraider or Btssm.

Although the stock tune is not particularly rated by anyone for ultimate reliability and driving satisfaction.

Technically, any cat back mods are stock tune compliant (according to the exhaust manufacturers) but personally I’d let my learning view results tell me.

So if you’re dead set on more noise, try a cat back, including the centre and muffs. Iirc avo, ultrex and tpc all do twin tips.

Or go a mid pipe with eg hotdog res, and gut the tbSTi muffs.
It has been done.
Or get the tbSTi tips attached to loud mufflers.

The actual Subi rumble is unequal length headers which technically, 2.5t Gt’s have, but perhaps aftermarket uel’s are more unequal

Being pre cat, you’ll probably need a tune, for which you’d get a 3” turbo back, anyway.

Having a wagon and being well over the hill, my current setup is... in my member profile.
But the muffs are modded wrx STi sedan muffs, 08+. (Hard to fit these on a lib sedan, if at all...)

https://www.google.com.au/search?biw=32 ... 6jGWNDNHRI

Hey I googled the forum for youse!!! (Gutted tbSTi mufflers)

Absolute tragedy the pics are no longer linked.

https://web.archive.org/web/20110307074 ... =10&t=4667
Luckily the pages were internet archived in 2012

[HOSTILE]

Thanks for your Intel mate, much appreciated!
You're right, Ultrex have a decent cat back that looks the goods. Would you know it drones much though?

Also I have found a stage 3 power pack from grimspeed in the States.. I'm thinking maybe just wait and do it properly first time round lol
Thoughts on this setup?

[LibertyTragic]

The Xforce is cat back and includes mufflers so it is the complete system from the cat to the back..

Hey Stifull, are the rear tips on the xforce muffler removable? As in is it a 4”tip slotted over a 3” tailpipe? I’m looking at xforce for my Gen5 but in order to fit behind my rear body kit I’ll probably need to do some shortening with a hack saw Having standard 3” tube on the muffler outlet would be much easier to work with.

[bigBADbenny]

Anti drone generally requires some sort of chambering to kill the resonant frequencies at cruising speed.

Options include baffled/chambered mufflers, glass packed turbo muffs, adding more mufflers/resonators in-line, or my favourite, side branch resonators aka helmholz resonators.

The latter can be tuned according to target rpm, number of cylinders and exhaust length and diameter.
The side branches are said to work best as close to the collectors as possible, yet some designs have them in the mufflers.

Either way, the idea is to add more volume/s to the system to let resonant sound waves bounce back for a degree of self cancelling.

But eg consider it might take 2 or 3 hotdogs to match one baffled muffler.
I’ve heard that a hotdog and a baffled mid deepen the tone of the shrill H6 for example.

I found a good balance to be 3” catted dump, baffled 3” mild mid and the wrx STi muffs modded for BL.
No drone, nice note.

With stock 2.5t headers, a 3” straight through cutback was only awesome at wot, and too loud everywhere else.
However a sedan is said to be more tolerable than a wag for drone/noise, due to different cabin acoustics.