# Factory Exhaust Question



## blk00ss (Jul 14, 2012)

Hey guys, I'm new here, and new to forums in general so I'm not the best at searching yet. Hoping someone can better help me understand the factory exhaust system. I'm buying my buddies 2005 bone stock GTO in the next week or so. Doing an axle back will probably be my first mod, but I'm a bit confused. The mufflers are towards the rear, but is there a resonator towards the front? Is the resonator kind of like a bullet muffler, and does this resonator cause the gurgle noise when decellerating, cause I hate that noise. I had the same issue with my 00 SS. Also, I know 04's were the LS1 and they may sound a bit different, but they seem to sound way better. Are the mufflers on the 04 located somewhere other than the rear? Can the 2005 have it's mufflers placed in that same location instead and does it help with the gurgle? Not looking for LOUD, I'm past all of that, but want a good low end sound, not wanting a plap plap drag car sound, and I don't mind it being louder than stock, or even opening up at WOT. Any helps is appreciated!


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## svede1212 (Nov 1, 2005)

The "gurgle" can be mitigated a bit in the tune but not eliminated as far as I know. Yes you can have mufflers placed in the '04 position with some custom work. The resonator removed will just make things louder. Borlas or Magnaflows will give you a nice deeper sound that's not too loud.


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## blk00ss (Jul 14, 2012)

Thanks for the help. I was leaning towards either the Flow master axle back, or the Magnaflow. Does Magnaflow make an axle back, or is it just the catback they offer? I've seen people refer to their Magnaflow as an axle back, but all my searches return a catback.


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## gtogooch (Dec 12, 2009)

If your wanting a decent rumble with not alot if any downshift noise, do a resonator delete and install some aftermarket mufflers like spintech maganflow or borla. I did this before I installed long tubes and catless mids and it was loud when you wanted it to be not all the time, and I didnt have any drone or unwanted resonance.


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## svede1212 (Nov 1, 2005)

The '05-'06 mufflers are placed further back and can be unbolted after the rear axle hence why it's called an axle-back. The cat-back is from the catalytic converters all the way back to the tips. On the LS2 either can be replaced altho the axle-back makes a lot more sense as the stock pipes are fine. FlowMaster are the most restrictive of the muffs mentioned, SpinTechs are loud, Magnaflow is deeper and quieter and Borlas just a touch quieter than Magnaflow.


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## Gotagoat (Jan 6, 2006)

Another good option is Kooks Afterburners. A high quality axle back with a deep tone and not too loud at low to mid RPM. I've had them for a couple of years and have enjoyed them.


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## blk00ss (Jul 14, 2012)

I'm not much of a Flowmaster fan either, but based on everything I've heard they have the best sound IMO. I don't like the sound of spintech, and the few clips I found with the Kooks axle back I didn't like either. The magnaflow sounds good, but also seems to be very quiet, like almost stock quiet. Please keep in mind, I'm listening through 2.1 PC speakers so I'm aware the videos may not do any of them justice. I don't want loud, but I would like more than stock, and little gurgle if possible. Maybe I can look at a axleback, x pipe setup.


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## Gotagoat (Jan 6, 2006)

The video clips don't represent anything like the sound in reality. If I'd depended on that, I'd not have changed from stock. Anyway, good luck with your choice.


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## svede1212 (Nov 1, 2005)

blk00ss said:


> I'm not much of a Flowmaster fan either, but based on everything I've heard they have the best sound IMO. I don't like the sound of spintech, and the few clips I found with the Kooks axle back I didn't like either. The magnaflow sounds good, but also seems to be very quiet, like almost stock quiet. Please keep in mind, I'm listening through 2.1 PC speakers so I'm aware the videos may not do any of them justice. I don't want loud, but I would like more than stock, and little gurgle if possible. Maybe I can look at a axleback, x pipe setup.


I know my Borlas are as quiet as stock cruising but any acceleration wakes them up. In fact they scream. Power is the #1 reason I've selected exhaust components and getting that at the most quiet level was second. Maybe I'm the only one trying to hold down the sound but I'd rather be quick. Walk softly and carry a big stick is more desirable than pickup truck loud. Also whatever you start out with will get louder both over time and definitely louder with each mod. Power adds sound. 

In person I think that Chokemasters are deep but sound like a big steel drum and Magnaflow and Borla are deep and smooth. The best test for an exhaust is not how many heads you can turn. Try pulling up next to a cop waiting at a traffic light at 2 am. You'll be amazed how much louder it sounds even to yourself.

No flyby yet but my garage rev.


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## Ironmn715 (Nov 30, 2012)

Any part number for the Borla pro xs muffers? Did you bump up to 2.5" here or are you still at the stock 2.25" pipe size?

'Moe

04 M6


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## jpalamar (Jul 22, 2008)

Corsa isn't much louder the stock while cruising but really wakes up above 2000rpm.


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## The Black Mongoose (Oct 16, 2012)

now heres something i havent noticed anyone mention about swapping their exhaust, how about any power increase. im going to try to do headers and exhaust. ive narrowed it down to most likely kooks headers, and cant really decide between the bassani, or the corsa, or the borla. any input


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## BWinc (Sep 21, 2005)

Anything after the cats will have minimal affect on HP.


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## Ironmn715 (Nov 30, 2012)

Its more about tone/sound than meaningful HP gains in my expreience. I feel like the stock 04 2.25" tube could handle 400HP without giving much up. To my knowledge smaller tube out back give you good low down TQ whereas larger diameter tube will give you better higher RPM performance(WOT).

My plan is JBA shorty headers, JBA catted mids(or uncatted that I weld the cats into), and X pipe from Pypes and then two MRT version 2 mufflers and 2 aluminized tails.

Best of luck with your exhaust. Let us know what if anything you end up doing.

'Moe


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## goats head soup (Mar 14, 2013)

Love those borlas.


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