Finally got the GMMG system and got it installed, and it is badass. At any rpm above idle it sounds wicked, but at idle and if you are just cruising it is quiet as can be, even quieter than the flowmaster muffle I had and you can't hardly hear it inside of the car. I'm definitely not complaining, cause I kinda like that and its sounds sweet whenever the car is pulling, definitely impressed but just wondering if anybody noticed that. Maybe its quieter since I have stock manifolds and Y-pipe? Like I said though, BADASS!

"I stood outside and listened to you going up the road, it sounds like an old muscle car" Mom

 

yep thats the way it is with stock manifolds and stock y-pipe...I'll be putting on a set of headers when it gets warmer...should wake things up just a little bit

 

same here

 

Those are awesome exhaust, too expensive for me though. I see your in Raleigh, me too. Are you on www.hpjunkies.com ?

 

The GMMG is kinda quiet at idle on a stock LS1 when fully-warmed up, but still a little louder/deeper than stock...But I agree, any throttle above idle and it becomes very pronounced in and out of the car. With my LT headers & highflow cats, it's not really any louder at idle (just clearer), but is much louder above 2k rpms and sounds really deep/mean all the way to redline. Definitely cool because every other cat-back system seems to get higher-pitched as the rpms rise under hard throttle (even with headers).

Now on my LT1, it idles louder and sounds just plain out evil even behind stock manifolds and cats...

Mike

 

Yeah, I am planning on headers and a new catted y pipe when the funds come in. I meant to ask if anybody knows why the standard tips with the GMMG system have that flat spot at the top edge like somebody held a grinder to the tip of them? and no, I'm not on hpjunkies but I ahve looked around on there some

 

My observations were the same as yours - surprisingly quiet at idle and at cruise, but awesome when you open the throttle. My wife's response was "Awesome! Deep and rich!" Another gal friend was major thumbs up when she heard it. Great sound when you get on it and no obnoxious drone cruising on the highway - the best of both worlds.

 

Affirmative on the flat edge at the top of the angle cut.

My tips tuck away pretty nice under the sport appearance package, so I've got no prob with them. On a non SAP Z I'd definitely prefer the cut had been full to tip, but it's not that bad. I prefer the stock GMMG tips over the oval ones on ANY camaro. Oval's for the birds, you know.

BTW, LOVE THAT GMMG SOUND!

 

Yeah, I meant to mention that, too. I dunno what's up with that cut on the top of the tip. It looks funky. Although I have a bird, I like the look of of good ol' American dual pipes coming out the rear. Don't care for the ovals. I don't have that ground effects package, and the cut tip looks wonky.