Anyone run GMMG?
Thread Starter
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Joined: Nov 2007
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Anyone run GMMG?
Like the title says...is anyone running GMMG on there 3rd gen? I'm just curious as to how it sounds on a TPI motor!
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Joined: Feb 2007
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Re: Anyone run GMMG?
I got it. Sounds good with stock headers but adding the headers really sets it off.
Junior Member
Joined: Jan 2008
Posts: 71
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From: Louisville Kentucky
Car: 1989 Pontiac Firebird Formula
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: Stock Gears
Re: Anyone run GMMG?
750 for any catback system is absolutely ridiculous. I wonder if it comes with a free air freshener?
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From: unknown
Car: 1992 Firebird
Engine: 3.1L
Transmission: Auto
Axle/Gears: 3:23
Re: Anyone run GMMG?
listen if $750 sounds like alot then you will be missing alot of good sound. Believe me the GMMG sounds the best on any GM motor. And believe me that $750 if well worth it for the quality. Many people like me are cheap we buy the flowmasters and then we find out that after a few months they lose their orignal sound. You pay for what you get. Just get the exhaust and dont worry what anyone says because you are the only one who will be driving your car and you are the one who says how your car should be. So go out there and buy a GMMG
Joined: Sep 2003
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Anyone run GMMG?
take it to a good exhaust shop preferably a performance shop and buy two chambered tube mufflers from stainless works or classic chambered or sweet thunder. then have them run the pipes. FAR cheaper than GMMG ridiculous mark up, possible to do it for 300-400 bucks like a normallly priced catback. Same thing as GMMG, its all a GMMG is. It uses more expensive stainless exhaust tubing tho but still is cheaper to have someone else make it for you.
I'm running a single chambered tube on my car at the moment. here is what it sounded like on my TPI L98...all stock internally with just some bolt ons.
http://media.putfile.com/Chambered-Tube-exhaust-clips
I'm running a single chambered tube on my car at the moment. here is what it sounded like on my TPI L98...all stock internally with just some bolt ons.
http://media.putfile.com/Chambered-Tube-exhaust-clips
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From: Louisville Kentucky
Car: 1989 Pontiac Firebird Formula
Engine: 305 TBI
Transmission: 700R4
Axle/Gears: Stock Gears
Re: Anyone run GMMG?
Yea man, if you have the money, by all means buy the GMMG. Just not my cup of tea though.
Thread Starter
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Trending Topics
Re: Anyone run GMMG?
My RS is running the GMMG exhaust. It's the only modification on the car, and was on the car when I purchased the car. I also have the stock exhaust and have been thinking of putting the stock exhaust back on....
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From: unknown
Car: 1992 Firebird
Engine: 3.1L
Transmission: Auto
Axle/Gears: 3:23
Re: Anyone run GMMG?
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Joined: May 2006
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From: Lake of the Ozarks, Missouri
Car: 1987 Pontiac GTA Trans Am
Engine: Basic Stroked SBC..383
Transmission: PerformaBuilt 700R4 3000 Stall
Axle/Gears: Moser 9in. 3:70s
Re: Anyone run GMMG?
How would you go about puting the GMMG on with long tubes? I have true duals with magnapacks and its old now love the sound but time for somethin new..Iv wanted it for a while..but I dont want a y pipe right under the tranny so it doesnt get hot. How would that work? Im ganna order mine pretty soon..but the car wont be done for a while =( the engine is in OK..=)
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Anyone run GMMG?
How would you go about puting the GMMG on with long tubes? I have true duals with magnapacks and its old now love the sound but time for somethin new..Iv wanted it for a while..but I dont want a y pipe right under the tranny so it doesnt get hot. How would that work? Im ganna order mine pretty soon..but the car wont be done for a while =( the engine is in OK..=)
if you dont wanna run a y-pipe then you have to keep true duals and not run the GMMG exhaust, just chambered tubes which is probly just as good sounding...i love mine.
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
Yeah...you have to run a y-pipe if you are going GMMG. Other wise like Orr89RocZ said...your best bet is to get the chambered tubes!
Come on guys...i'm yet to hear GMMG on a 3rd gen!
...that's the reason for the whole thread!!
Come on guys...i'm yet to hear GMMG on a 3rd gen!
...that's the reason for the whole thread!! Re: Anyone run GMMG?
I bought the car to show and the car is completely stock, so with the exhaust on, I lose points b/c it's not stock. I do like the sound of the exhaust and there is nothing wrong with it and I do highly recommend it. I've even thought about taking it off the RS and putting it on my SS....hehe...
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From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Anyone run GMMG?
Their price went up Jan 1st this year.
I picked up mine for $735 with the oval tips on a group purchase a few years back. I'd buy it again. The system is still as much fun to listen to as it was new.
I picked up mine for $735 with the oval tips on a group purchase a few years back. I'd buy it again. The system is still as much fun to listen to as it was new.
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
I bought the car to show and the car is completely stock, so with the exhaust on, I lose points b/c it's not stock. I do like the sound of the exhaust and there is nothing wrong with it and I do highly recommend it. I've even thought about taking it off the RS and putting it on my SS....hehe...

Senior Member
Joined: Feb 2007
Posts: 268
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Re: Anyone run GMMG?
Ill try to get a soundclip tomorrow. Have to find the usb cord for the camera first though.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Anyone run GMMG?
there is one on youtube i believe that was posted here awhile go.
http://www.youtube.com/watch?v=h0FM5eVASdM
http://www.youtube.com/watch?v=uiIsvubpzl8
http://www.youtube.com/watch?v=hd3EbmJPhsI
http://www.youtube.com/watch?v=h0FM5eVASdM
http://www.youtube.com/watch?v=uiIsvubpzl8
http://www.youtube.com/watch?v=hd3EbmJPhsI
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Joined: May 2006
Posts: 254
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From: Lake of the Ozarks, Missouri
Car: 1987 Pontiac GTA Trans Am
Engine: Basic Stroked SBC..383
Transmission: PerformaBuilt 700R4 3000 Stall
Axle/Gears: Moser 9in. 3:70s
Re: Anyone run GMMG?
Id like to keep the true duals but if I go with chambered tubes and make it duals it wont sound the same will it? I thought the GMMG tubes were different..
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
So...did anyone get a clip of their system? Also...if you have the oval tips...i would like to see pics!
Joined: Sep 2003
Posts: 25,895
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Anyone run GMMG?
GMMG i do honestly believe use stainless works chambered tubes.
If you run 2.5" true duals over the axle, on both sides, you can mount the tubes where the GMMG system lies, and run tips out the back. It will sound close to the gmmg but probly louder.
GMMG is a single catback that splits into 2 mufflers. true duals will have 1 muffler per side, so it will have more sound but will be close to that of the gmmg.
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From: Lake of the Ozarks, Missouri
Car: 1987 Pontiac GTA Trans Am
Engine: Basic Stroked SBC..383
Transmission: PerformaBuilt 700R4 3000 Stall
Axle/Gears: Moser 9in. 3:70s
Re: Anyone run GMMG?
Well I dont like running over the rear end..but with a factory "style" I would but not duals. I hate exhaust tips on any car..Ill have to bend mine down somehow and where.
Joined: Sep 2003
Posts: 25,895
Likes: 429
From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Anyone run GMMG?
well you dont have to tips if you dont want. nothing wrong with duals over the axle.
else just run the tubes under the car and dump them before the axle, 45 degrees out. Run an H pipe between them and you'll have a great sounding system, similar to gmmg but not the same
else just run the tubes under the car and dump them before the axle, 45 degrees out. Run an H pipe between them and you'll have a great sounding system, similar to gmmg but not the same
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From: Old Bridge, NJ
Car: 1992 Camaro RS
Engine: 383 SuperRam
Transmission: 4L60
Axle/Gears: 3:23 Posi
Re: Anyone run GMMG?
Im going to go with the GMMG exhaust I think it sounds pretty cool. Im moving my exhaust completely to stainless steel. Starting with stainless works headers and y pipe from hawks and the GMMG cat back. I just have to modify the y - pipe to put two bullet style stainless steel cats on.
Last edited by Fast92RS; Feb 9, 2008 at 09:29 PM.
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From: unknown
Car: 1992 Firebird
Engine: 3.1L
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Re: Anyone run GMMG?
Im going to go with the GMMG exhaust I thinks it sounds pretty cool. Im moving my exhaust completly to stainless steel. Starting with stainless works headers and y pipe from hawks and the GMMG cat back. I just have to modify the y - pipe to put two bullet style stainless steel cats on.
Thread Starter
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Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
That looks good. I want different tips, because i don't like my Flowmaster tips, so i'm thinking about getting a set of the oval GMMG tips. This picture really helps me on what i should do! Thanks a lot man!
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Joined: Feb 2007
Posts: 268
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Re: Anyone run GMMG?
I just found the usb cord for my camera. Ill make a vid/sound clip tomorrow when I get out of school.
Senior Member
Joined: Feb 2007
Posts: 268
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Thread Starter
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
Sounds really good from the exterior. Is it loud on the interior when you have the door closed?
Do you think it would sound like that on a 305? I have the same headers as you...but i have the 5.0 instead of the 350 (unfortunately!)
Do you think it would sound like that on a 305? I have the same headers as you...but i have the 5.0 instead of the 350 (unfortunately!)
Senior Member
Joined: Feb 2007
Posts: 268
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Re: Anyone run GMMG?
When you get to about 2 grand its loud in the interior. It should sound pretty close on a 305.
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
That's kinda how my exhaust is! I think it sounds the best at 2 grand to be honest!
I'm thinking about getting a whole new set-up...but i'm not sure! I would like to do Hooker Long Tubes w/ an ORY and GMMG cat-back. But i don't really want to fork out the money right now! We'll see!
I'm thinking about getting a whole new set-up...but i'm not sure! I would like to do Hooker Long Tubes w/ an ORY and GMMG cat-back. But i don't really want to fork out the money right now! We'll see!
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From: Fairhope, AL
Car: 89RS(other cars & pics in vBgarage)
Engine: LO3, 305 TBI Mildly Modified
Transmission: BakerBuilt 700R4 w/B&M Megashifter
Axle/Gears: 3.23 Auburn Pro Series LSD
Re: Anyone run GMMG?
yea that sounds good
Senior Member
Joined: Feb 2007
Posts: 268
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From: South Daytona, FL
Car: 88 Iroc
Engine: L98 5.7 LITER V8 TPI
Transmission: THM 700R4 Auto
Axle/Gears: 2.77 Posi. Lim Slip
Re: Anyone run GMMG?
Yea my car has a high idle I need to get fixed. It was ideling about 1000 to 1100 rpm. Couldnt get the nice low rumble from the lower rpms.
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From: Old Bridge, NJ
Car: 1992 Camaro RS
Engine: 383 SuperRam
Transmission: 4L60
Axle/Gears: 3:23 Posi
Re: Anyone run GMMG?
That sounds sweet. I wonder how it would sound with a set of long tube headers.
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From: unknown
Car: 1992 Firebird
Engine: 3.1L
Transmission: Auto
Axle/Gears: 3:23
Re: Anyone run GMMG?
My friend has a SLP LM2 on his 305 firebird its kind of quite, no matter what exhaust you put onto a 305 they are quite. The 350 is where the GMMG exhaust really wakes up.
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Junior Member
Joined: Nov 2007
Posts: 60
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From: Northern Indiana
Car: 1998 Camaro SS
Engine: LS1
Transmission: 4L60E
Axle/Gears: 3.23's
Re: Anyone run GMMG?
My car is a 305 and it's pretty loud! I bought the car w/ the whole exhaust (in my sig) and at about 2 grand she is pretty loud, of course the stupid cat quiets it a little. I have an exhaust clip (not long only a couple revs) if you all want to hear it!?
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From: Moneta, VA
Car: 89 formula 350
Engine: ls1 magnuson tvs2300 supercharger
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Re: Anyone run GMMG?
there is one on youtube i believe that was posted here awhile go.
http://www.youtube.com/watch?v=h0FM5eVASdM
http://www.youtube.com/watch?v=uiIsvubpzl8
http://www.youtube.com/watch?v=hd3EbmJPhsI
http://www.youtube.com/watch?v=h0FM5eVASdM
http://www.youtube.com/watch?v=uiIsvubpzl8
http://www.youtube.com/watch?v=hd3EbmJPhsI
You forgot the wide open throttle video though lolhttp://www.youtube.com/watch?v=0Qwas...eature=related
Member
Joined: May 2006
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From: Lake of the Ozarks, Missouri
Car: 1987 Pontiac GTA Trans Am
Engine: Basic Stroked SBC..383
Transmission: PerformaBuilt 700R4 3000 Stall
Axle/Gears: Moser 9in. 3:70s
Re: Anyone run GMMG?
Im ordering the long tubes from hawks with a Y pipe and then going to get GMMG after the headers come in!! I cant wait!!
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Joined: Dec 2001
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From: El Paso, Texas
Car: 2000 Trans Am and a 85 Iroc-Z
Engine: The Mighty LS1& 305 just beat meTPI
Transmission: 4L60E and 700R4
Re: Anyone run GMMG?
Best catback I have chosen..of course the GMMG is on my LS1 T/A but I am buying another GMMG to replace my overdone Flowmaster 80 series. Without cats...no thanks. Catted Y-pipe is the way to go with the GMMG IMO. I am ditching the Shorties and I too will be going with the LT's from SSW and catted Y(custom from my fav exhaust shop)to set my Iroc apart from the also rans. Hopefully my little LB9 can keep up with my T/A before I get my head and cam kit from Vengence next spring. Hell I need a head and cam kit for my TPI just to get to where my T/A is stock. Damnit 
Go GMMG!!!!

Go GMMG!!!!
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From: Cali
Car: 1992 Z28
Engine: 350 TPI
Transmission: World Class T-5 5speed manual Trans
Axle/Gears: STOCK G92 performance 3.42
Re: Anyone run GMMG?
it sounded like a million bucks on a stock TBI with manifolds!!! i just bought a system for my (mostly) stock 350TPI with headers cats intake etc.
ill try to put a before and after video up on youtube if i find out how to get the damn thing working.
ill try to put a before and after video up on youtube if i find out how to get the damn thing working.
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From: Houston, TX
Car: 1989 GTA
Engine: SuperRam 350
Transmission: Pro Built S/S TH700R4
Axle/Gears: 3.27
Re: Anyone run GMMG?
How do you find the GMMG is on a convertible? It's the loudest muffler system I've heard for F-bodies on a coupe. Can only wonder it's too loud on a convertible?
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From: Cali
Car: 1992 Z28
Engine: 350 TPI
Transmission: World Class T-5 5speed manual Trans
Axle/Gears: STOCK G92 performance 3.42
Re: Anyone run GMMG?
Here is a Before:
http://www.youtube.com/watch?v=GW3Us9Gxd8Y
Ill put up an after once i recieve the catbac in the mail!!! They said only about one and a half weeks till it ships!
http://www.youtube.com/watch?v=GW3Us9Gxd8Y
Ill put up an after once i recieve the catbac in the mail!!! They said only about one and a half weeks till it ships!
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From: El Paso, Texas
Car: 2000 Trans Am and a 85 Iroc-Z
Engine: The Mighty LS1& 305 just beat meTPI
Transmission: 4L60E and 700R4
Re: Anyone run GMMG?
Hopefully you get it sooner. It took 5 days for mine to get to me from MMacon, GA to Avondale, AZ. So you might get it sooner, or hopfully depending on the day you ordered it.
I personally might switch my GMMG from my T/A to my Iroc and throw a B&B Cat back on my T/A. So might be cool not to spend that $700 for another GMMG..oh wait the B&B costs $640....damnit. Haha. Still love it, let's hear that new exhaust when you put it on!
I personally might switch my GMMG from my T/A to my Iroc and throw a B&B Cat back on my T/A. So might be cool not to spend that $700 for another GMMG..oh wait the B&B costs $640....damnit. Haha. Still love it, let's hear that new exhaust when you put it on!
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