PontiacBonnevilleClub.com

Hi Guys…

I am very new here and have joined since my friend has an 05 Bonne..
I have a question..

I have an 05 GXP and would like to know if there is a difference in the mufflers from a NON-GXP to a GXP car?!?

Are they chambered the same way? Which would be quieter by design?

Thanks
Frank

Do you want a quieter muffler? I honestly don't know if there is a difference. The only way to know would be to cut both in half. I don't think you'll find a quieter muffler though, as a V8 is going to have a certain growl no matter what. I suppose you could put in a longer resonator.

Not quite a Mechanical issue... Moved to General Chat.

Why do you want a quieter exhaust?

MOD - thanks for the direction.

-> I am looking to quiet down the car...
(have a new child)...and I am trying to reduce as much of the exhaust tone on the daily driver..

Any and all advice is much appreciated...
I also wonder if there is an aftermarket that is pretty quiet..

Thank you very much for any help..
Frank

As a fellow GXP owner, the only time the car is loud at all is at WOT, and it's not much louder than any other stock GM vehicle. I HIGHLY doubt putting in a 3800 exhaust will make it quieter, hell it could make it louder. GM spent plenty of hours doing NVH testing. The GXP is plenty quiet from the factory. Like I said before, you could add an additional (or replace the stock with a larger/longer) resonator. I doubt your kid will notice it.

thanks for your reply.

I thought that the Resonator was for drone related sound?
Does it also affect the overall volume level at all rpms?

thanks
Frank

The resonator is for drone, but I can only assume that a bigger resonator would also trap more sound.

I know why you wanna make it quieter but why make it more quiet!!! the sound is beautiful! Also welcome to the board.

as someone mentioned above, the only time the GXP is loud is at WOT. i cant even hear mine under 4k rpm
i doubt a longer resonator would make a difference.
id leave it the way it is, any changes i would say it'll only make it louder

cutting off the mufflers would help

gonzo4191 wrote:cutting off the mufflers would help

The GXP definitely has a audible growl at anything off idle. I wouldn't call it loud, but it's pretty aggressive for a stock sedan. I've even had a few people ask what exhaust I had put on it. It is definitely louder than the exhaust note on a stock Caddy with a Northstar.

If you want to make it quieter for whatever reason, there are mufflers available that can do that. I think your best bet would be to go to a good muffler shop and tell them what you want. Keep in mind that a quieter muffler might cost you a few horsepower depending on the design.

I guess maybe if you found a DTS at a junkyard you could take the mufflers off of that? Honestly, it makes a little noise, but nothing loud or intrusive, IMO. I drove my dad's all day Saturday and no one who was with me complained that it was too loud. I doubt it will affect your son/daughter. Might make them into a car fanatic though.

I hear ya Beast, I do love the sound of my GXP, and I don't consider it loud or obnoxious by any stretch. I would not recommend messing with it, but if you want it quiet, the typical muffler shop carries "granny mufflers" that can make a car quiet (at the expense of horsepower).

Our baby sleeps through just about anything when in the car. Babies actually like some "white noise". Smooth application of throttle will be more important than volume, as long as it's not straight-pipe loud.

But yelling at the dog for something when the baby has fallen asleep in her chair... that'll scare the crap out of her. Ask me how I know...

Make sure you get stainless mufflers if you decide to replace.

You can put this on right after the resonator(if the GXP does not have a resonator mount it right after the cat).
http://www.moroso.com/catalog/categoryd ... Code=35054
I did this to my car to cut down on the drone that I had with my custom exhaust(it did for the most part).
What it also did was quiet it down just a little bit, but did not change the sound(tone) of the exhaust.
It was like if you went and turned down the volume of the tv, you get the same sound just not as loud.

ROD

My 18 month old loves riding in mine.

UPDATE

Some interesting facts have come up.

Had the car inspected.
The loudness level has been here since day 1.

The issue is that the tops of my mufflers are full of holes.
i can assume that this has been a slow progression through the two years i have had it.

I have replaced them with a solid new pair (stainless) from a local wreckers..
Nice thing too is that they have a date code on them...and are less than 2 years old.

The car sounds great now..
The WHOLE issue here was I have not heard the same car beside me ever with a good (non-perforated) exhaust ....had I !?!?! I would have known from day one what the issue was...

It seems that the impression i gave here was that I was looking for NO noise or that i was getting old..
Not the case really...i love a good V8 rumble...and now i have it..

thanks to all above who tried to help.

all is well..

Frank