trans9_5am

I have purchased the GMMG catback system from another board member and have it sitting in the shop. I have been planning my exhaust setup for a long time and was wondering if it would be worth it to cut the GMMG catback where the single 3" pipe meets the dual 2.5" pipes. The reason i am considering this is i want a dual setup through chambered mufflers that exit out the back and i like where GMMG has placed the mufflers. I have also heard from numerous people that the sweet thunder and summit chambered mufflers dont compare to the sound of the GMMG ones that is why i wanted to post this thread to see how much of a difference the sound is. Is it really worth cutting up an expensive exhaust system or should i just use the GMMG as a template and attempt to replicate it with some sweet thunder mufflers? By the way, i am going from jet-hot LT's => Dual E-cutouts (3") => X or H-pipe (3") => Both pipes on pass side => over the axle => then through chambered mufflers (GMMG if everyone thinks its worth it) => out to chrome 3" round tips

Let me know your opinions especially if you were one of the people who said they other chambered mufflers dont compare to the GMMG's

Brandon

hsyr

Since your going with such an expensive exhaust setup I would suggest this. Cancel the cutouts. From what I've read/heard a cutout on gains ~2HP over the GMMG setup since it flows so well and if your planning on going duals with LTs it will just add weight and kill the ground clearance. IMO not worth the $. Also, I wouldn't hack up the GMMG system, I'm sure it flows well enough that going to duals isn't worth it. If its the sound your after, go with Jet-hot LTs, no cat, 3" Y pipe, then straight back into the GMMG but get the optional tips. Still expensive but not nearly as bad as the setup you want now.

trans9_5am

I already have the GMMG and the optional oval tips. I would really like to put an x or h pipe in there for sound and go with a dual setup though. I am not sure about the e-cutouts because yes they are expensive. Honestly i like the sound of most guys running the duals with chambered mufflers and dumps before the axle but i think its dumb looking for a daily driver to have slots on the back bumper (TA) and not have any exhaust coming from it. Either way, the cam i have in my 355 is going to make some noise no matter what exhaust i go with but i really want to know someones oppinion on how much differrent the GMMG mufflers sound than other competitors??

Only reason i was considering e-cutouts is because i think they are pretty cool

Brandon

SiDeWaYZz28

will you sale me your setup???lol let me know

2000LS1Z28

If you already have the cat-back system just waiting around to go on, then heck no! Have you ever actually heard the GMMG on an LT1 in person before? It sounds fantastic (just a deep classic muscle car tone all the way to redline). And only gets better with LT headers and a highflow cat(s). It sounded extremely deep/loud when another kid on this board revved up his otherwise stock '94 LT1 with it and some Mac headers and a higflow cat for me in person back in the spring.

Just seems silly to hack up such a nice system when the sound is already killer. Yeah true duals with an X or H sound vicious, but I actually like the GMMG hooked up to some headers better. True duals are just too racecarish and raw for me personally. BTW, the GMMG flows very, very well too as the dyno has proved this on many highly modified rides with it...

But if you must have the true dual set-up, then just sell the GMMG and buy an already built dual system from Lanes or Texas Speed & Performance and use some Sweet Thunder Chambered mufflers with them for what you want. Or a good exhaust shop could fab you up one using those mufflers as well...

Mike

trans9_5am

Yes i want the true dual setup. The whole reason for my post is to see if there really is that much of a difference in sound of the sweet thunder mufflers from the GMMG ones. I have heard this from people but i want to know how much of a difference the sound is. I think the idea i have for this exhaust system is going to be pretty bad azz but i am not made of money and want to get everyones opinion before i go cutting this thing up. If anyone has heard both and can give a direct comparison, please chime in.

For everyone that has posted, thanks for the replies.....all good thoughts so far.

Brandon

ZBLKHELLRZR

Dual's vs GMMG? Man that's a hard one to describe. But I think I'll be goin out on a limb saying the GMMG sounds better than duals. But if you must go dual's don't hack the GMMG up. Just sell it and do what the others suggested. I'll buy it from ya if ya do.

trans9_5am

Well it kinda is already hacked up. The guy i bought it from just used a torch to get the exhaust system off his car. He cut it right behind where the clamp is where the two pipes meet over the axle. It can easily be rewelded but since it has already been hacked into, i might as well just do some more hacking if i feel the need to go that route . It has never been done before as far as i know. Maybe i can get the benefit of both worlds, duals plus the quality sound of GMMG mufflers??? I could always reweld the system and sell it if i dont like the sound but i feel it will sound pretty damn good.

Brandon

OutsiderIROC-Z

Stupid question time. What does GMMG stand for?

trans9_5am

Not sure. This is all i know:

http://www.gmmginc.net/

Brandon

Mikey97Z

I always wanted to see a true-dual setup where the GMMG chambered pipes were used under the car, one pipe on each side before the axle. Then dump before the axle or whatever.

truedualws6

I think it would work fine for either both pipes on one side or one
pipe on each side of the rear axle. Just imagine the CMMGs in place
of the dynomax in the picture.

http://www.bfranker.badz28.com/misc/td10.jpg

Bersaglieri

What I would do: sell the GMMG and let someone have the oppurtunity to buy and experience its glory. Then buy chambered mufflers of your choice and make your dual setup you want. That exhaust isnt hacked up at all, thats how I got my GMMG when I bough it used, welded it right back together with ease. I believe your potential setup may sound ok, but not any better than what you have right in front of you. Either way it seems you are just going through this for "the hell of it" anyways saying you want cut-outs cause they are cool. You have the best exhaust on the market in your hands, I am not sure why you'd hack it up when you could pass it on to someone else. Perhaps you havent taken into consideration the fact that the Entire GMMG exhaust is designed and tuned to perfection, to the point where even the bends in the pipes were made exactly to specifications to get the sound just right. This exhaust isnt made by some half-wit honkey hill-billies, its made by one of if not the most respected name in aftermarket F-body companies in the world. If GMMG is world renowned for their spectacular aftermarket F-bodies and you think that you are going to improve on the sound that gives cars like the ZL1 and newest "Mr. Chevrolet" supercars their raw attitude I think that you are mistaken and will be unsatisfied and upset you wasted not only your time but also your money.

-Dustin-

trans9_5am

Your statement is very clear and convincing. This is one of the reasons i posted this thread. Exhaust is very important to me and i am stuck trying to decide what will give me the best performance as well as sound. I know the GMMG exhaust is the best out there and that is why i was trying to integrate it into the true dual setup i was planning on running. Only thing i was going to do was cut the pipe where the 3" meets the 2 2.5" pipes so that it was more of a true dual setup but i guess no one likes the idea Only thing on my design that would be different from GMMG's is that it is a dual setup and not a single exhaust that breaks into two. Dont really see how this could effect the sound of their system that much but could see how flow could be slightyl increased. But as i said earlier, you guys are giving me something to think about before i go about this whole exhaust process. I appreciate all the responses.

Brandon

truedualws6

I'll have to correct you on that. I like that idea, in fact the CMMG was about
the only system I considered initially for the very reason of cutting it off at
the juncture of the 3-2.5s and using it in my true dual setup. The deciding
factor was the inability to get just the portion I needed from GMMG. I would
have had to buy the whole setup. I'm actually very happy with the ultraflow
now that I know how loud the GMMG is. I like the quiet, sleeper effect.