There have been a few reports of CELs with GMG's exhaust - you may want to ask the owner's under what circumstances the CELs occurred...and whether or not it was an issue with the car or the exhaust.

https://www.6speedonline.com/forums/...ml#post3697002

https://www.6speedonline.com/forums/...ml#post3234975

 

I have the GMG for past 13 months, no cell... yet.

 

GMG has great products, and exhaust. Check out the Fabspeed system as well...it also sounds great. When selecting exhausts, sound is really subjective. You have to hear them by yourself and see what you like best.

 

Still haven't gotten a clear estimate of loudness of GMG vs EP1 at hot engine idle and at 5-25 mph sspeeds. For those having experienced both exhaust systems on their turbos, and using a 1-10 scale with stock exhaust being 1.0 and for EP1, a 5.0, would the GMG in loudness be at 6.0 or 7.0 or perhaps closer to EP1's 5.0??

 

i have a 996 turbo with the gmg w/c sport exhaust. full 3" with cats and a 4" slash tip. it was on the car when i bought it. using a ifone decible app the noise at 70 mph was 104 db!! the drone was unbearable in 6th gear. i had a shop neck down the end elbow and reinstalled the oem tips. noise dropped to under 90 db and drone is all but gone. it sounds amazing on the outside and just rumbles in the cabin when on boost.

i would suggest you try to find a turbo with a speedtech exhaust. its very well built sounds great and will be my next unit when i tire of this one

 

I had the GMG on my car for about 18 months.
The sound is intoxicating, but pretty loud, especially with cold idle.

I also did several pretty hard track days, and seems that it got louder. Talking with my tech, seems that the "wool" in the muffler can get a bit fried at high temps, and thus get louder over time.

I also had 2 CEL events, about 6 months apart. Both times was just driving along...

The last time GMG sent a adapter to move the O2 sensor a bit.
Initially GMG said it never happens, but then again they have the adapter so make what you will of that.

In the end, my car is parked under my young daughter's bedroom, and I was feeling self conscious in neighborhood driving...so I went back to stock for now.

My .02..

 

^-^Well there you have it johnw.

If you're seriously unhappy and find the EP1 too loud for your taste the only real alternative for you is to go back to the stock system. If the EP1 isnt doing it for you I have no idea what will. Funny thing is with all of this is I've heard some members opine the EP1 is as quiet as a mouse, most of which haven't even heard it in real life if i may add .

Look at the bright side johnw, you won't have any difficulty selling the EP1, if that's any consolation. There are guys here and on RL that will take your arm off for it and pay top money. So best to get it off and put it up for sale. I mean why put up with something you're clearly not satisfied with?

 

Not sure but you may be mildly straying back to your prev-6peed era suggestive behavior. Can't you be helpful without the crap Thought for a second there might be a better NA-like sounding exhaust and was just checking. Not anxious for another $1K labor/$5-10K exhaust/4 hr wait time/multiple shipping issues/wife complaining to be disappointed. Learned that lesson with EP1. EP1 is good if that is all there is. Thinking about new turbo and while there's time, just doing some searching for best-sounding/trouble-free exhaust if that's OK.

 

Pre 6 speed behaviour?Please explain?

And crap? Please explain exactly what is it have said is crap?

Reading the thread its pretty easy to interpret you are looking for alternatives which is perfectly fine by me, but pretty well anyone here knows what you are looking for i.e. no drone and not noisy is only available with the stock system. You have made it fairly obvious over your regular posting on this subject you have an issue with what you have now, which is no problem for me personally, but If you want noise and no drone then outside of a stock system i'm not sure what else is there? Im mean you do want no drone and not noisy correct?

EP1 is reknown as having no drone, but it does make noise, and therein lays your problem, no? So why put up with something that is a poor fit for your personal requirements? It is a system you would be able to sell very quickly and for good money so why not do that? Again just a suggestion but valid given your circumstances. And given your requirements the stock system is an ideal selection....and probably your only logical alternative again given your outspoken requirements.

So again what did i say that was crap? ....and "pre" 6 speed behaviour? Please explain? I havent been anywhere else other than RL and that was well after i joined 6.....and i don't think i knew you before then....or did I?

 

I just wanted to chime in regarding our World Challenge sport exhaust systems.

First off let me say THANK YOU for all the positive reviews on this forum over the years.

We take pride in the systems that we build not only in the workmanship but in the quality of materials we use. All systems are TIG welded to AWM specification which is a aerospace specifications most exhaust companies do not weld to this spec. Secondly we only use a USA made aerospace grade stainless steel additionally the catalyst are made for us specifically by HJS in Germany to our specifications and lastly our systems are handcrafted in the USA.

Our systems the parts we manufacture and sell under the GMG World Challenge line are the direct result of our proven professional racing experience in World Challenge and ALMS over the last 17 years.


If you are in the area please feel free to stop by the facility (Now 30,000 sqft) and I would be happy to show you around the facility.

 

With all due respect, I think your post is a bit biased sir. I dont see anything offensive in speed's post, and I believe your remarks are uncalled for... No one is blaming you of anything, you just turned very defensive very quickly here...

Guys relax. Its a car forum.

 

I have the GMG Ti system on my GT2. Since the stock one was Ti I figured why add any more weight.
Compared to a Europipe locally the sound is a bit deeper and louder. Can't say there is any difference in cold starting tho.
I live in a neighbourhood of gearheads so another loud car is no matter....
There is no drone unlike a Fabspeed system I had on my previous Cayman S. It does set off car alarms in parking garages though.
After a day at the track it does get noticeably louder probably from burning off the carbon inside the mufflers.
Workmanship, especially the welds, are meticulous and the whole system worthy for a P-Car.
I had a CEL re the O2 sensors but after I put a right angle O2 spacer on (a straight one won't fit) it cleared. That was last fall and was driven about 100km before putting it away for the winter. I will see in about 2 weeks when it comes out of hibernation if it appears again.
Loudness is a subjective thing. The GMG is louder but sound better IMHO.

...and no way am I going back to the stock system...total happy

 

....well I'd truly love to hear what the problem was all about. Odd really. ....like he's only PM'd me 16 times in the past asking advice about stuff which I've always gladly helped. Strange. ...never thought there was any underlying issues.. oh well...sigh. I can't pick em any more. .....maybe it's just a full blue moon happening over that way?