Allergik2dyin

Once I get my car it will be strictly a daily driver, literally, my only means of transportation. Id also be doing headers and a y-pipe or ory. I want the most power I can get and that great muscle car sound. But I don't want anything really loud, raspy, or drones inside the car. Just a deep, clean rumble. I thought I was definitely set on GMMG. It has a great sound once you get on the throttle and fairly tame during normal driving. I always assumed that true duals would be too loud and obnoxious for a DD. But with TDs I could get everything I needed and be about the same as gmmg, but with a little more power. So, which would you recommend for me? For those with gmmg, do you regret not getting true duals? Should I keep cats if I go with headers? ory, or y-pipe? For true duals, which muffler? Dumped, over/under the axel? Thanks for all of your input in advance.

jmm98LS1

iTrader: (28)

Don't know if it's possible, but try to find some people w/different exhausts to give you a ride so you can see what it's like. Sound is so subjective it's hard to decide over the internet.
Since it's your only mode of transportation, you need to have all your mods thought out before you start. Do you want to lower it? If so, you might want to stick with a catback. If you choose a y-pipe/catback setup, put some cats on to help keep the rasp down.
I think duals sound better than any y-pipe setup, but they're hella loud especially when dumped. You could have them run out the back and have them tuck very well, but it won't be cheap. To me, the most liveable setup on a daily driver would be duals run out the back and put your mufflers after the rear axle. That would give you more room to put a bigger muffler and tone it down some. Just my .02.

Allergik2dyin

The only car I've got to ride in/drive was one with a corsa catback, pacesetter lt's and a tsp 224 cam. I didn't particuarly like the sound of the catback. It was a good sound, but not loud enough even under WOT with those mods. From what Ive read and listened to, gmmg is alot louder with LTs and cam etc and obviously so is true duals. But I'm just trying to get some opinions as to which would be better for my application. With true duals I know I'd probably have to run them out the back, but with which mufflers? Any more help would be great.

cyphur

iTrader: (10)

With Kooks stepped headers(1 3/4 to 1 7/8), Kookrs ORY, and GMMG, along with an F13 cam, my car is obnoxiously loud. Sounds GREAT for a weekend driver or even a pleasure car, but to drive 70+ miles a day(which I do) its too loud.

I have an SLP Dual/Dual sitting in my backyard right now waiting to get fabbed/installed.

Iron Sights

I have GMMG now, and I'm going to switch to true duals in the next couple of months. I love the sound of GMMG, but I'm looking to gain some more power and distinctive sound when I put the longtubes on. I don't plan to run cats, and I don't want to get the "rasp" most people complain about with GMMG, LTs, and an ORY.

lilbuddy1587

iTrader: (1)

For a DD I'd suggest either(for true duals of course) magnaflow 4x9 OR borla xr-1 oval or round muffler. Both have a very deep idle, nice and mellow at cruise, and SCREAM at WOT without any rasp WHAT so ever. Both are stainless steel as well.

zaner

iTrader: (16)

I recentl went from having longtubes, off road y pipe, and gmmg, to putting on 2.5" true duals w/ spiral flow mufflers dumped at the axle.... oddly enough the true duals is quieter than my gmmg exhaust and deeper too w/ a noticeable improvement in power up top...

SSJIMMY

iTrader: (8)

what about you guys with GMMG have you ever thought of using those muffluers in a true dual setup i would like to see and hear that.

ninety9ta

iTrader: (2)

I have a 99 t/a that is a dd, and I drive the damn thing everywhere. I put about 18,000 miles on since I bought it last April. I went with GMMG and don't regret it one bit, and still enjoy every minute of it. However, I went with the GMMG over true duals because of emissions purposes, otherwise I think I would have gone with an off road x pipe with some sweet thunder mufflers. I think the GMMG is the next best thing to duals. Good luck.

Cerberus

Do you have LT'S with your GMMG?

nokeman

iTrader: (30)

Go true duals. It will be loud but there wont be any rasp. Either way though I dont think you will be disappointed.

Allergik2dyin

I would eventually go with a cam. For that I was between the f13 and a 224ish cam. I imagine with either gmmg or td's it would be pretty loud. But with gmmg, ory, and headers its obnoxiously loud for a dd? So for true duals, some failry quiet mufflers like the magnaflow 4x9 or borla xr-1 (any others for my application?) Should I run cats with a td set-up also? I also assume I should run them out the back even if it is more expensive, it would be worth it considering its a daily driver? Basically...what TD setup will give me the sound Im looking for without the rasp or drone in the cabin? Thanks for all of your responses, theyre very helpful.

Also- if anyone could post up some vids of idle, normal driving, WOT, whatever, that would be awesome.

Cerberus

Here is a link to one of my favorite videos on LS1sounds.com. This guy has Kooks LT's, Cats, and GMMG: GMMG with Kooks LT's and Cats

It is the setup I want eventually.

STRETCH'S T/A

iTrader: (13)

i have kooks lt's and catted y with my gmmg and i couldn't be happier. its not to loud in the car when cruising and it is definitely an attention getter when going wot. sorry no video yet, working on it.

Cerberus

What Y-Pipe did you use? Stainless?

Allergik2dyin

That sounds so sick WOT. Thats exactly what I want. Im just wondering with the mods I'll eventually do (headers, cam) which exhaust will be best. That set up right there sounds absolutely sick. But then which would fit me better a true dual set-up with headers cats out the back? Decisions, decisions....

Allergik2dyin

to the top

2000LS1Z28

It's simple IMO...If you want to run cats, then go with the GMMG 3" cat-back (along with Kooks LT's & highflow catted Y). I have that set-up on my stock internal '02 Z28 and it sounds ridiculously mean at WOT (but in a good way). Not quiet at idle, but not loud either (you can definitely tell it's aftermarket and louder than stock). Part-throttle rumbles nicely (you hear it in the car), but it's not what I'd consider loud, nor does it drone any. And of course, it's extremely loud at full throttle. What I really like about it is that it retains it's composure and sounds deep all the way up to redline whereas most other systems don't. Once I drop the cam I want in it, this set-up will sound absolutely perfect in my book.

However, if you don't want to run cats, then true duals all the way...The GMMG (like most other cat-back systems), will get really raspy without the cats and doesn't sound nearly as good IMO (the sound is ruined this way). Whereas the true duals don't get raspy without cats and sound mean as $hit. I've been in a catless true dual/cammed LS1 before and it was really loud inside (and out of course). You've got to remember that most people run duals dropped at the axle, which creates a lot more interior resonance and droning inside the car. While the cat-back systems goes all the way out the rear. You could always run the duals out the rear as well, but that will cost you a lot of extra money.

Bottom line, peak horsepower will be similar between these two systems, but you'll gain a more under the curve with the catless true dual set-up. In the end though, it all comes down to what you really want (what type of sound, look, volume, interior noise, max power, etc.). I personally do not care for the obnoxiously loud "race car sound" of most true dual set-ups and actually like the sound of my GMMG/LT header/highflow cat combo better. Others do not though...

Hope that helps,

Mike

Strahley

iTrader: (4)

If you don't want drone, rasp, or the yawing cat noise, I would suggest either staying stock or going with true duals

Scotty-Z

iTrader: (5)

Yeah, go with the duals.