club.liberty.asn.au

Well, time has come to gut more mufflers (oooohhhh the controversy).

Anyway, this weekend just gone I've FINALLY got around to whipping off the '05 Lib GT mufflers and taking to them with the grinder to gut the bastards!

The one thing I did notice was how much easier it was to gut out than the WRX muffler (only 1 chamber wall to worry about). Each muffler took around 30mins to do which is pretty good considering. Either that or I'm finally getting the hang of doing these muffler gutting exercise.

So, here's the quick pics of the equipment required:



Pull off the tips (2 x 10mm nuts hold these on):



Get the angle grinder and cut a nice big rectangle on the flat edge of the muffler. You'll also need to cut out the 2 spot welds (so the rectangle will actually come off ) that attach to the chamber divider (you'll see it in the next pic).



Then lift off the top, behold the chamber and weird J pipe trumpet!!!



Note the resonator on the actual exhaust pipe outlet, the weird J pipe with its inlet pressed up at the very rear of the muffler canister. All designed to impede flow speed. Here's a picture of the chamber wall that the air has to flow through to get to that trumpet outlet:



Plenty of holes but still far from efficient.

So, I adjusted it.



Have lined up the welder for the next phase so stay tuned for completed pics and a new set of MP3 audio sample. :thumbs:

Yes, controversal topic indeed! But alas, to each their own! But nice work there, Craig! Very clean cuts and the gutting was done nicely.

Great to see you follow through with your conviction despite the controversy, as I'm curious on how this turns out both in terms of sound and air flow. Keep it up!

I like to teach, not preach Arith.

No point not walking the walk. What's to be gained.

What is so "controversial" about gutting a muffler?

Nothing really. Just some historic debates on here. Bit of an 'in joke' really.

its good to see what they looked like inside

good post, thanks for the pics. I didnt realise that was the layout inside the OEM mufflers

James

Nice 'adjustment' Craig.

How much louder is it than stock, and anything gained in terms of responsiveness or power/torque?

w00t!!!! My mufflers are ready!!!! Will pick them up tomorrow morning.

Hey cpitts those look fimiliar.

Intresting to hear the outcome.

Good Luck.

I hate to nitpick... but your trumpet for the exit of the muffler sucks

Coolo.. big grinder for a little job

i saw an article about this being done to a 911 turbo. it had a great result with power and sounded fantastic, not too loud but very gutsy. goodluck with it!

For absolute max flow, why don't you gut your catalytic converter as well. Not entirely legal though.

To answer the few questions that popped up:

1. Gutting CAT's - nup, the $60K EPA fine just isn't worth it
2. Trumpet on the exhaust outlet - That's stock, so no change, I'll put the tips back on tomorrow when I get the muffs back and it'll all be stock again
3. THERB3 - Familiar, yep but yours, NO (sorry). I ended up with another set from an '05 GT as the tips were actually bigger on the GT and angled the same as the rear bumper (unlike those from the RB!!) Weird, hell yes!! No stress tho, I'm sure I'll be able to perform some surgery on the set from the RB to see just how restrictive they are.

4. The internal modifications have now actually been enhanced to include a stainless steel pipe from the inlet to the outlet (mandrel bent of course) with holes drilled in the pipe in the straight section for least flow interruption but enough to hopefully keep things a bit quiet. (hopefully)

5. How much louder, what do they sound like?

I'll record an MP3 on Saturday so stay tuned in the arvo or evening (depending on how I go).