It was a stormy night in the land of puyallup...but all was not silent for in the distance the bright flash of a welding arc could be seen for miles around. So to the hacking of pipes, grinding of metal and various naughty words resounded throught the night untill a mighty roar and rumble followed by the spewing of smoke and terrible flame ( ok...no flame) frightened the villagers and they trembled in there foreign imports.

I decided paying $700 for the "official" Gmmg chambered exhaust was just a little too much....so.....I purchased two 18" Sweet thunder chambered mufflers and went to the local parts store for some extra pipe. Now If I were to do this again I would order the mandrel bent pipes in the exact dimentions but as it happens its just as well I didnt because my design changed. To copy the exact GMMG design proved too difficult without a pipe bender and I wasnt top happy with the thought of welding the pipe next to the gas tank so I ended changing the design but got the same result. Having never welded before some of the welds were a little fugly but with a few pounds of weld on each joint it aint going no place and no leaks as far as I can tell. All in all Im in the set up about $200 ( versus $700) and its 2 1/2 and not all manderel bent so not AS good as the GMMG but it sounds real nice and is getting better the more I drive it. The $500 I saved is enough for some GFX and it was fun building the exhaust. I'll post pics of the results soon for anyone interested.

 

I think it would be interesting to see some pics.

Al

 

I KNOW I would like to see some pics as I have two brand new 2.5" glasspacks collecting dust in the garage.

 

i too was considering the sweet thunder one.. but i would of gotten a real long 3" pipe and threw it in the I-pipes place.. then I would make a single 3" dump over the axel.. meaner IMO...

and if you have the means.. I WANNA HEAR IT!
hhehe

 

Why go to all of that trouble. If you want a cheeper version of the gmmg why not get the loud mouth. The only differances I see between the gmmg and the loud mouth is the loud mouth has one chamber instead of two and the chamber is in front of the rear end instead od behind it.. The advantages of the loudmouth over what you are doing is 1) the pipes are larger and 2) the bends are more free flowing. Both will give you more hp.

I am thinking of going with the gmmg but in the back of my mind I am thinking the loud mouth would give me the same results because it has a simalar design. I have until spring to decide.

 

Well i personally went with the GMMG chambered exhaust. I was told to try what you did with the Sweet Thunder mufflers, but I wanted mandrel bends and descent welds. I am 100% satisfied with the GMMG. I would like to see pics of your GMMG replica and am very interested in hearing it, to compare.
Also, just to note, the Loud mouth and the GMMG sound nothing alike whether one chamber or two. I have tested this with my friends SS (loudmouth) verses my Trans Am (GMMG). The loudmouth has more interior resonance and has a more straight through sound, compared to GMMG which has not as much resonance and a great baffled sound with NO raspe. No i am not saying the GMMG is better, because we like what WE like, just comparing and attempting to make things clear

 

I'll dowload the pics from the camera tonight and with luck get a sound file for you to listen to.

I thought about replacing the I pipe but I didnt have the means to bend it over the rear end correctly and I was working on the ground so space was tight.

The loud mouth ( IMHO) is not the same as the GMMG sound / tone. I much preffered the GMMG to the loudmouth in that respect. Also the loudmouth didnt need any "creating" or "finagling" ...which was kinda fun.

My Gmmg replica dosnt sound exactly like the sound clips on the website, those cars probably have headers, free flowing Cats and a three inch pipe going back to the GMMG set up, my Z28 is stock all the way from the exhaust manifolds to where the pipe used to plug into the stock muffler...but, the sound is good and I expected it to improve still over time but im pleasantly suprised to find that even after just three days of long drives the tone is becoming deeper and the baffled sound is really coming through more and more. It really sounds good coming down on compression on the freeway ( untill it pops but thats kinda cool too).

Overall the real GMMG is better im sure for flow and sound but my mock Gmmg is good and getting better with each 60 mile freeway trip to work and for $200.00 and a lot of fun making it Im well pleased

 

How about some pics of the 57 also.

 

sounds good to me, if i knew how to produce sound clips i would post them, because my car is stock with the GMMG. that would give an idea to how close the sounds are. I'll try to dig something up. I'll need some time though.

 

OK......remember that I had NEVER welded anything in my life up until this point and I had to make the Y-pipe from scratch and the 180 bend from 2 90's. A sound file is on its way ( with luck ) will post that tonight.


see picks here:

http://imothphfiles.homestead.com/files/EXhaust_1.jpg

http://imothphfiles.homestead.com/files/Exhaust_2.jpg

http://imothphfiles.homestead.com/files/exhaust_3.jpg


By request (DARK AGE 53) Pictures of my 57.. not an F-body but still a cool chevy. These are before and after interior shots, Im de-chroming and sanding the exterior so I can get it painted so its not much to look at right now, but the inside looks good...take a look see.....

The BEFOREs:

http://imothphfiles.homestead.com/fi...h1-_before.jpg

http://imothphfiles.homestead.com/fi...ar-_before.jpg

The Afters:

http://imothphfiles.homestead.com/fi...nger-after.jpg

http://imothphfiles.homestead.com/files/rear-_after.jpg


I'll get a sound file tonight and post it so stay tunned.

 

kewl pics.. i dont think i will ever understand dual outs unless they are true duals, but hey! I give you an "A" for effort and ingenuity! heheh


Waiting on the sound clips.

 

Thanks for posting those pics of your 57, it looks great.

For your first time welding I think you did a great job, where can I get more info on those Sweet Thunder mufflers. Thanks

Al

 

http://www.sweet-thunder.com

The guy is real nice.. Spoke to him for like 30 min one day..
Seems very helpful.

 

http://www.sweet-thunder.com

I got the 14 gauge Aluminised steel ones ( same stuff flowmasters are made from) since stainless is harder to weld and I didn't have stainless pipes anyways. The guy is real nice and shipping was well packaged and quick. The mufflers are very good quality- 8 pounds each! and solid. Excelent welds ( I cant do them but I know what they are supposed to look like) might be orbital welds or TIG but whatever, they are done right.

Highly reccomended.

 

Thanks for the info guys, I see he's in Michigan...I might take a drive someday and see if he'd be interested in making a custom set for my Prowler.