Need to quiet down GMMG, options??`

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Nov 25, 2010 | 12:04 PM

SSDriver

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From: Burbank, CA

Need to quiet down GMMG, options??`

First I want to say that the car sounds amazing, its just too damn loud. It wasn't that bad until I did the heads and cam. Now it twice as loud as my 69 big block vette. Not a good thing in CA.

What are most people using? Are they adding a muffler or simply replacing the GMMG resonators? If so what mufflers look and sound good.

Nov 25, 2010 | 12:50 PM

WSsick

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From: St. Peters, MO

My friend's Spiral flow is pretty quiet, so you could just throw one in the Y in addition to the GMMG to make it quieter.

If you want just a straight muffler swap, I'd say Hooker.

Nov 25, 2010 | 05:34 PM

hitmanws6

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From: Orange, CA

I was in your same position when I did my H/C on my LT1. I added a Flowmaster Merge and a magnaflow bullet to the I pipe, did a pretty good job at quieting it down. You could also add cats

Nov 25, 2010 | 08:05 PM

RevGTO

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From: Wichita KS / Rancho San Diego

After adding LT's to my GMMG, it took cats, a powerstick in the I, and resonator tips to quiet it down and kill the rasp. I had an FM merge in my Y.

Nov 25, 2010 | 08:10 PM

bayer-z28

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From: N. Falmouth MA

I wouldn't hack the GMMG.. you could get some good money for it if you decide to sell it eventually. I'd add a resonator to the Y section of piping before anything. I know Kooks has some small resonators, but I can never find them..

Nov 30, 2010 | 06:31 PM

BOBS99SS

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From: Elyria Ohio

You could sell it to me,

Nov 30, 2010 | 07:29 PM

180ls1

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From: San Diego

Quote:

Originally Posted by WSsick

My friend's Spiral flow is pretty quiet, so you could just throw one in the Y in addition to the GMMG to make it quieter.

If you want just a straight muffler swap, I'd say Hooker.

the spiral flow will also kill power quite a bit it ran in a single setup.