NIRVANA

I've finally decided which exhaust system to buy and I'm going to go with the GMMG with oval tips. I think it looks/sounds the best even though it's a bit pricey. Anyway, I was wondering if anyone knows what kind of gains I can expect on a dyno. I'm assuming it's probably around 10HP on a stock car w/ lid like mine.

onebadz

You are probally right with the 10 RWHP estimate, I think it will be somewhere close to that give a few take a few. Good Luck

WeS

Damian

iTrader: (89)

The same as every other GOOD flowing catback. 10-15 rwhp depending on the car.

2000LS1Z28

Not quite what you're looking for (I also did this with a lid) , but I gained EXACTLY 24rwhp & 22rwtq (SAE corrected) with ONLY a Direct-Flo lid and the GMMG Chambered Exhaust over bone friggin stock! The dynos were only 750 miles apart and done on the same dynojet chassis (Speed Inc). Later on, I leaned out the A/F ratio some with a MAFT and the gains jumped up to 26.5rwhp & 26rwtq. Not bad at all for two simple bolt-ons and nothing else! Obviously, taking into account for what a lid is generally worth, this exhaust no doubt makes good power.

BTW, contrary to what many used to think, the GMMG has now consistently been dyno-proven to be one of the better flowing cat-back systems on the market for our cars. I have routinely heard from others or seen sheets that have shown it to lose hardly anything (or anything at all) over an open cutout on high horsepowered cars.

But if you love the sound and looks of this system, you absolutely will NOT be dissapointed with it as soon as you get it on your car...

GMMG

Mike

WS.SEX

iTrader: (6)

I gained 18rwhp with the gmmg.I guess the gains from car to car are different.I dyoned the car at gmmg and yes the sound is evil now i need some headers and a TC.

Smallwood

I'll think you'll be pleased with a GMMG.

wild thing

iTrader: (2)

I have a whisper carbon fiber lid with k&n and gmmg and i dynoed at 309 horsepower and 327 torque. It is a 2000 ss and those are the only performance mods i have on it. I dont care if i lost power i would still buy gmmg i love the way it sounds especially on a cold start it rumbles at idle. I would definitely get it if i were you.

Vengeance Racing

GMMG is the only way to go.
But what the hell do I know


I pulled an entire exhaust system off at the dyno and only made 8RWHP over full exhaust and that is with a 30min cool down.

NIRVANA

Thanks for all the info guys, I think I've made the right decision. I was thinking about doing the Loudmouth for a while, but I want to do headers next year also and I heard too many stories about the dreaded rasp, so GMMG it is!