Pontiac Firebird 1967-2002 - Borla or GMMG?

I like both a lot..What do you guys run.I don't want rasp,I want deep bellow..And NO,its not going to be cammed up,new heads,or intake.Which sounds best at idle and taking off? I saw the youtube vids but some are pretty bad and not really a good real world test..Opinions are welcome..

GMMG all the way, borla= raspy with LTs

Really? Hmmm..wish I could hear them both live,the youtube vids aren't the greatest..They both sound great..

My Borla had no rasp with the closed plate in with my LT's and off road Y. Before that it sounded great with the open plate on stock manifolds.

If you can try to meet up with some cars in your area, so you can hear them in person so you can make up your own mind. Everyone on here will have their own opinions, and you my not agree with them. It would suck to spend $1k on a exhaust that did not hear first, and end up hating the sound.:nod:

Thanks guys..Dan your right,but I have no idea where to find someone..I'm not that worried about it..From the vids,I can tell that the Borla and GMMG are higher quality than the rest and sound better..I've had SLP 3" on all my Iroc's and it was good,but I don't like the hollow sound.Borla and GMMG don't sound like that,they have a deep bellow that I really like..Or am I out in left field here?

To meet up with locals go to the locals section on this site, and depending on what state you are in (there might be a local f-body site)

Then.... when you watch youtube vids most are with headers (these cars sound completely different without headers) You cant judge the vids with or without headers...

thanks man..good info..I'll look into it..I just think the quality from Borla and GMMG is alot different than SLP,Hooker,Magnaflow,and I can't stand flowmaster!

GMMG sounds badass with long tubes & a cam... I think it's one of the best sounding exhausts out there, that's why I bought it.

just bought a gmmg! The sound on the ls1 with stock manifolds and y pipe is very deep sounding with no rasp. Can't comment on the Borla, never heard it. Heard the gmmg and had to have it!

just bought a gmmg! The sound on the ls1 with stock manifolds and y pipe is very deep sounding with no rasp. Can't comment on the Borla, never heard it. Heard the gmmg and had to have it!

Thanks man..Is it on your car now? The SLP just doesn't do it for me..It sounds more annoying than anything IMO..

GMMG sounds badass with long tubes & a cam... I think it's one of the best sounding exhausts out there, that's why I bought it.

Heads kinda open the sound up too. ;) I have some clips in my sig. On stock manifolds, LTs and CATTED Y, and finally Heads/Cam on the dyno only though. More vids in a couple of weeks when the season warms up to get it out of storage.

I really like the GMMG tube crimped mufflers,if they even ARE mufflers.. :)

Ive had alot of compliments on my gmmg....i love the sound and quality of it. Has a nice deep sound at idle and screams when u get on it. I dont think ud regret it....try www.ls1sounds.com, there are some stock ls1's on there with gmmg for sure.

GMMG is great with the stock set-up and works well with LT's as long as you run cats. LT's and no cats makes it extremely loud and raspy.

I had Borla on my Z, just the catback, and really liked it but the one thing that bothered me was that sound only comes out of the non-muffler side, the passenger side, but overall the sound is a nice deeper aggressive sound. With that being said, I will be getting GMMG to go with my CME tips on the SS pry next summer, so I say GMMG.

..............slp :)

Long tubes-GmmG-No Cats- idontthink mines raspy-Very loud tho. Tuner told me everyone had to leave the building when it was on the dyno because it was to loud.
I love my GMMG though. wouldnt trade ot for anyhtign

GMMG is great with the stock set-up and works well with LT's as long as you run cats. LT's and no cats makes it extremely loud and raspy.

I've had both - I had Borla on a 2000 M6 both with stock manifolds and LT's. I went with GMMG on the 2002 and I've never regretted it. The Borla didn't sound bad at all, but the GMMG is everything that people on here said it was. You are right about both being higher quality than what other companies offer - there is no comparison between these systems and Flowmaster, etc...

Thanks for the advice..I will probably go with GMMG when the time comes..Getting the WS6 hood,fitted,painted and installed next week..Then I think I'm going with gears,then exhaust.. :)

im going gmmg also..love the sound..and also like the way the oval tip setup looks on the ws6

i vote gmmg, simply because i don't see them around too often... at least where i live.

They both sound good but I also prefer the GMMG. My buddies car had the GMMG on it and went to the Borla when he had a new cam installed. He promptly put the GMMG back on and gained more power over the Borla on the dyno.

Good to know..I think I will go with GMMG when the time comes..Too many people like it..