GMMG = too loud!
GMMG = too loud! Am I crazy to want to hack up the GMMG to quiet it down? And by hacking I'm talking about installing some type of bullet in the I-pipe. Or would it be better to just sell the thing and find something more suitable/quieter?
I remember the LT1 days sitting in my car wishing the constant loudmouth drone would go away but it sounded so good otherwise that I didn't care. Then I got a cam, installed headers, removed cats... all the typical stuff and well that was a big mistake. Had to sort through several catbacks before I found one that was quiet enough on the highway which was the SLP 2OTL. Though it looked funny, it sounded great.
So fastforward to a few months ago and I'm back in an Fbody. This 02 WS6 was supposed to be bone stock but oddly enough it had the GMMG catback which at first I thought was awesome given the fact it is one of the most desireable on the market. And though I don't drive it a whole lot, I can't stop having flashbacks of the LM days and how nasty that thing got when I started opening up the exhaust. I really want to quiet it down NOW rather than react to it being too loud later. What's the best option?
I remember the LT1 days sitting in my car wishing the constant loudmouth drone would go away but it sounded so good otherwise that I didn't care. Then I got a cam, installed headers, removed cats... all the typical stuff and well that was a big mistake. Had to sort through several catbacks before I found one that was quiet enough on the highway which was the SLP 2OTL. Though it looked funny, it sounded great.
So fastforward to a few months ago and I'm back in an Fbody. This 02 WS6 was supposed to be bone stock but oddly enough it had the GMMG catback which at first I thought was awesome given the fact it is one of the most desireable on the market. And though I don't drive it a whole lot, I can't stop having flashbacks of the LM days and how nasty that thing got when I started opening up the exhaust. I really want to quiet it down NOW rather than react to it being too loud later. What's the best option?
My loud meter is calibrated like it used to be. 10 years ago I thought it was cool but now I just think it's loud lol. And when the neighborhood dogs bark when I fire it up, that is too loud. This car is otherwise basically stock too.
This is what I am thinking of doing with mine. Not hacking up the GMMG exhaust like you said but hacking up my Kooks ORY is just as bad but it will kill the rasp.
https://ls1tech.com/forums/generatio...vids-pics.html
https://ls1tech.com/forums/generatio...vids-pics.html
Don't hack up either. The Y doesn't change anything just as the above post proves. Just take out the I pipe from the GMMG, buy a pieces of straight, a 90, and a bullet muffler and make a new I-pipe with muffler installed. This is exactly what I'm doing after my H/C Kooks 1-7/8" and ORY are installed. I know it will be way too loud then since it's already borderline for me now just with pacesetters and a TSP catted Y.
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12 Second Club
Joined: Sep 2005
Posts: 4,273
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From: Bucks County, Pa.
It must be that indestructable/immortal attitude of youth which makes them somehow really believe that it "will not happen to ME".
That, or they just do not expect to even make it to 50??
Hearing aids (which will NOT help with the constant, LOUD ringing), are NOT COOL!
Ask me how I know about this.
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iTrader: (1)
Joined: Jul 2004
Posts: 251
Likes: 1
From: the shit hole of Albuquerque, New Mexico
What all of the young'uns on here just do NOT realise is that the sound pressure of these systems will DESTROY your hearing by the time you get to your 50s, as well as giving you PERMANENT tinitus (ringing in the ears), even if you are only driving them for 50 days a year.
It must be that indestructable/immortal attitude of youth which makes them somehow really believe that it "will not happen to ME".
That, or they just do not expect to even make it to 50??
Hearing aids (which will NOT help with the constant, LOUD ringing), are NOT COOL!
Ask me how I know about this.
It must be that indestructable/immortal attitude of youth which makes them somehow really believe that it "will not happen to ME".
That, or they just do not expect to even make it to 50??
Hearing aids (which will NOT help with the constant, LOUD ringing), are NOT COOL!
Ask me how I know about this.
Sorry for going OT 
I don't think my GMMG is too loud and I run it with a set of Kooks headers and their ORY. But then again, I've been around airplanes my entire life and can't hear anything either. Sometimes I think the only reason my car doesn't seem loud to me is because my hearing is already so bad.
Joined: Nov 2003
Posts: 6,216
Likes: 236
From: Wichita KS / Rancho San Diego
Tinnitus is horrible ... my brother suffers from it. But he still happily cruises his WS6 with a Flowmaster catback that is MUCH louder than my car was stock with GMMG.
I thought my GMMG was perfect with stock manifolds, cats, and converter. Hi-stall converter and it was a little too loud but acceptable. LT's and it was way over the top. I hacked mine up with a catted Y, powerstick in the I, and resonator tips. Finally I ditched all of it for ORY and a Maxflow setup and have never looked back.
Look at the "sticky worthy" thread for a complete discussion of GMMG solutions.
I thought my GMMG was perfect with stock manifolds, cats, and converter. Hi-stall converter and it was a little too loud but acceptable. LT's and it was way over the top. I hacked mine up with a catted Y, powerstick in the I, and resonator tips. Finally I ditched all of it for ORY and a Maxflow setup and have never looked back.
Look at the "sticky worthy" thread for a complete discussion of GMMG solutions.
TECH Resident
Joined: Oct 2008
Posts: 801
Likes: 1
From: Anaheim Ca.
Am I crazy to want to hack up the GMMG to quiet it down? And by hacking I'm talking about installing some type of bullet in the I-pipe. Or would it be better to just sell the thing and find something more suitable/quieter?
I remember the LT1 days sitting in my car wishing the constant loudmouth drone would go away but it sounded so good otherwise that I didn't care. Then I got a cam, installed headers, removed cats... all the typical stuff and well that was a big mistake. Had to sort through several catbacks before I found one that was quiet enough on the highway which was the SLP 2OTL. Though it looked funny, it sounded great.
So fastforward to a few months ago and I'm back in an Fbody. This 02 WS6 was supposed to be bone stock but oddly enough it had the GMMG catback which at first I thought was awesome given the fact it is one of the most desireable on the market. And though I don't drive it a whole lot, I can't stop having flashbacks of the LM days and how nasty that thing got when I started opening up the exhaust. I really want to quiet it down NOW rather than react to it being too loud later. What's the best option?
I remember the LT1 days sitting in my car wishing the constant loudmouth drone would go away but it sounded so good otherwise that I didn't care. Then I got a cam, installed headers, removed cats... all the typical stuff and well that was a big mistake. Had to sort through several catbacks before I found one that was quiet enough on the highway which was the SLP 2OTL. Though it looked funny, it sounded great.
So fastforward to a few months ago and I'm back in an Fbody. This 02 WS6 was supposed to be bone stock but oddly enough it had the GMMG catback which at first I thought was awesome given the fact it is one of the most desireable on the market. And though I don't drive it a whole lot, I can't stop having flashbacks of the LM days and how nasty that thing got when I started opening up the exhaust. I really want to quiet it down NOW rather than react to it being too loud later. What's the best option?
Last edited by slow ride 02; Feb 5, 2013 at 11:33 PM.
I did not find it too loud at all, but it did have horrible drone at 2k rpms, despite what anyone says. I put a bullet muffler I had laying around and it cut it down just enough, it probably only decreased the overall volume on the outside slightly.
you arent crazy...i my self would go for quiet over loud. and btw ive seen MANY threads of people adding bullets to GMMG. it cuts the rasp..thats what i read. PLUS bullet in the i pipe is not hacking. i say try it out and see how you like it..if you dont just trade it with someone from the members above...i would trade just because it looks good 
but am on the other side of earth so...
but am on the other side of earth so... This catback isn't too terribly loud currently and managable for now... sounds like a smoother loudmouth if you ask me. But with headers and high flow cats I know it will get nasty. Hell there really isn't a muffler at all so I can see why. By biggest issue right now is the drone and why some done while others don't has never made a lot of sense to me. I must have been spoiled before because I have experience with SLP LM, dual/dual, 2OTL, Corsa, Borla and now GMMG but the 2OTL while odd looking really sounded great... no way would I ever stick it on a TA though.
Not really interested in trades just yet unless you live in Kansas so I can hear what you have.
Not really interested in trades just yet unless you live in Kansas so I can hear what you have.