Which flows better, Magnaflow or GMMG?
Thread Starter
TECH Apprentice
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From: Brook Park, Ohio
Which flows better, Magnaflow or GMMG? Which flows better, Magnaflow or GMMG?
There's a GP for GMMG on www.f-bodyhideout.com. The price is $650 shipped. I'm trying to decide if I should pull the trigger. For the last month or so I've been trying to decide between GMMG and Magnaflow. Unfortunately, I haven't heard either of these systems in person. Any comments, opinions, or words of advise would be appreciated!
Sorry, I'm sure this has been a topic of conversation in a number of other posts.
Thanks,
Jim
There's a GP for GMMG on www.f-bodyhideout.com. The price is $650 shipped. I'm trying to decide if I should pull the trigger. For the last month or so I've been trying to decide between GMMG and Magnaflow. Unfortunately, I haven't heard either of these systems in person. Any comments, opinions, or words of advise would be appreciated!
Sorry, I'm sure this has been a topic of conversation in a number of other posts.
Thanks,
Jim
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From: Houston,Texas/College Station
Re: Which flows better, Magnaflow or GMMG? Get gmmg you will have no regrets and it will definitely outflow maganaflow gmmg are one of the best if not the best cat-backs out there, that is why all the zl1 supercars have them
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From: Michigan (Holland/Grand Rapids)
Re: Which flows better, Magnaflow or GMMG? Get the GMMG! 
I just had mine installed yesterday and the quality and sound is AWESOME!! 
I have heard the Magnaflow and the GMMG on several cars and I believe that if you get the Magnaflow you will be happy............until you hear the GMMG in person.........they you will be wishing you had the GMMG. 
I just had mine installed yesterday and the quality and sound is AWESOME!! I have heard the Magnaflow and the GMMG on several cars and I believe that if you get the Magnaflow you will be happy............until you hear the GMMG in person.........they you will be wishing you had the GMMG. 
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From: Petaluma, CA
Re: Which flows better, Magnaflow or GMMG? They've done flow tests of all the catbacks & the Magnaflow was the second best flowing catback behind the LM exhaust. I have the Magnaflow catback right now & with LT's it sounds great. That being said I have yet to hear GMMG in person.
TECH Enthusiast
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From: Michigan (Holland/Grand Rapids)
Re: Which flows better, Magnaflow or GMMG? Who has done all this testing? Where can we see the reuslts? I'm not doubting you I was just currious. ............No matter what the results are I still wouldn't trade a GMMG for a Magnaflow. 
............No matter what the results are I still wouldn't trade a GMMG for a Magnaflow. Re: Which flows better, Magnaflow or GMMG? Yes evn the Mustang Magazines (they have more money for testing then GM high tech) have tested hundreds of exhaust systems and MagnaFlow is always on top or close to it. They sound incredible with LT and are all stainless. $425.00
Nate
Nate
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Re: Which flows better, Magnaflow or GMMG? The GMMG outflows the Magnaflow. Its been tested.
Nate, I dont think the Mustang magazines have tested the GMMG since its LS1 specific, so your statement doesnt really help this guy. Thanx
Nate, I dont think the Mustang magazines have tested the GMMG since its LS1 specific, so your statement doesnt really help this guy. Thanx
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Re: Which flows better, Magnaflow or GMMG? GMMG is not LS1 specific, it is F-body specific. I want to ear a sound cip o this magnaflow, I am in themrket for something new now, and was looking at GMMG, or Loudmouth/Dynomouth, and have never heard nor seen Magnaflow. I love dynomouth, it is flawless if you like loud, and GMMG is flawless if you like a uniqe sound when you want it 
. Both are THE highest flowing exhaust systems for the F-body, and I would imagine that Magnaflow is right with them seeing their design is like a large bullit style myffler.
. Both are THE highest flowing exhaust systems for the F-body, and I would imagine that Magnaflow is right with them seeing their design is like a large bullit style myffler. 
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From: Columbus, OH
Re: Which flows better, Magnaflow or GMMG? Actually I believe the gmmg is LS1 F-body specific... I doesn't fit on a vette... but by the same token I don't believe it'll fit on the v6 F-body... and I don't think it's design will work with an LT1 car. But of course, with enough work, you can make any exhaust work with any car. Hehe.
I doesn't fit on a vette... but by the same token I don't believe it'll fit on the v6 F-body... and I don't think it's design will work with an LT1 car. But of course, with enough work, you can make any exhaust work with any car. Hehe. Re: Which flows better, Magnaflow or GMMG? Go on their site, you shall see it on a 3rd gen, and a 4th gen. I don't know if it fits on a LT1 car, but your right, you can always make it fit.
Re: Which flows better, Magnaflow or GMMG? 
On The Tree
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From: Naperville IL
Re: Which flows better, Magnaflow or GMMG? I have the Magnaflow on my car and I love it. Plus you can get it for half the cost of a GMMG on Ebay. The GMMG better flow alot better to justify the cost as far as I'm concerned.
Re: Which flows better, Magnaflow or GMMG? i dont remember what the GMMG flows but the Magnaflow flows 1100cfm only beat by the SLP loudmouth@2200cfm
anyone go t flow #s for the GMMG????
anyone go t flow #s for the GMMG????
Re: Which flows better, Magnaflow or GMMG? Dynomax Racing Bullit Muffler= 2100cfm on most tests, but I have seen anywhere between 1500-2300cfm. GMMG is at around 1500-1800cfm not too shabby.
Thread Starter
TECH Apprentice
Joined: Feb 2002
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From: Brook Park, Ohio
Re: Which flows better, Magnaflow or GMMG? Thanks for all the replies 
Feel free to keep them coming.
Also, does anyone have pictures of a TA with GMMG exhaust?
Thanks,
Jim
Feel free to keep them coming.
Also, does anyone have pictures of a TA with GMMG exhaust?
Thanks,
Jim
Re: Which flows better, Magnaflow or GMMG? How much flow do you need with 400 RWHP. I have a Magnaflow and love the sound except for the rasp betweem 2200 and 2800 rpms. It's really loud at WOT. I am thinking of getting a true dual set up if it will give me 10 hp. WHat do you think?
Re: Which flows better, Magnaflow or GMMG? i went with magnaflows, excellent high quality stainless steel setup and the 3.5" tips look bad ***, and for 300 even i couldnt pass it up. sound clips of my setup in sig, on stock heads and cam. though cam not for long
Re: Which flows better, Magnaflow or GMMG? I just got my magnaflows with lt's installed. i like everything about it except that dumb crackle glasspack sound at 2500rpm and at WOT it screams which is awesome.
