The previous owner had them pointed straight down, like they come from the manufacturer.

TBH, it's not that the GMMG is THAT much quieter, but it did change WHERE the sound was. With the turn downs, the sound is just under the rear floor pans. Drone was terrible at cruise 1800-2200 rpm, couldn't hear the radio, couldn't have a conversation, & everything in the car rattled. It was very responsive to throttle though & snappy.

The GMMG doesn't spin up as quick mostly because of the Y-pipe & cats but the sound is now at the back bumper.
I had to change it to pass emissions. Speaking of the back bumper, I went on a cruise with a buddy of mine & stuck the go-pro on the back bumper. WOT around 11:20.

He has turn downs, but also has 3.5" with chambered mufflers & it sounds nice.You can still hear mine when the go-pro was in his car...

I can't speak to the stock car sound since I've never had one But if going from stock to turn downs, then yes, I would consider them obnoxiously loud.
I've been eyeing the rear exit true duals for awhile now.

 

For those interested, heres 2 vids of my car with SE LTs and SE TDs, just as they come from SE, no changes other than better clamps.



if someone wants to embed those, that would be swell.

 

Whoa, this is great info. Yep, that is definitely quite loud! Sounds pretty sweet though!

True duels existing from the rear it is. Having a convertible I need all the help I can get

 

If you want to quiet them just put some spirals in the mufflers.

 

Which ones did you use?

 

Does anyone know what bolt thread/size is for the center hanger? Thanks.

 

Finally finished putting the rear exit kit on. Now that it's on I'm very pleased, though I think I still need to adjust the area around the drivers side x pipe to get it up more. A few comments:
-Sounds MEAN. Probably one of the best sounding exhausts you can get for an LS1. Despite all the comments about it being too loud, I was actually surprised with how perfect the volume is. I can still hear my music and hold a conversation as long as the passenger isnt whispering.
-Put it on along with the 1 7/8 headers and it's definitely way faster
-I wouldnt even bother with the clamps at all. I didnt listen to all the comments about them and assumed the new design would be okay (Its NOT! Please save yourself some time and dont risk messing up your pipes with these clamps.) I used jegs lap band clamps and they're miles better. The speed engineering clamps at the point of breaking were somehow still allowing the two pipes being connected to move freely.
-Some of the pipes were either damaged in the mail or werent constructed properly, I had to take some time with vice grips bending the ends so they'd fit together
-Only got 4 rubber hangers even though there are 5 necessary with the new hanger location. Not a big deal, just ended up zip tying one of the tips up

Overall extremely good value, even if it's not perfect. Make sure you're using a jack and pushing the pipes up as high as you can when tightening the clamps. At stock ride height I only even have problems if I'm not careful over especially annoying speed bumps. Thanks for this product SE!

 

Purchased headers and true duals last year February and installed them last April.
I modified the 1 7/8” headers for air pump tubing and installed Magnaflow metallic cats to keep things clean and easy on inspection day.
Made a bracket for the factory transmission hanger. Used the supplied clamps with exception of lapped clamps at the headers.
It still had more drone than I cared for so I installed spiral inserts.
I’m at stock hight and have plenty of clearance after hours of adjusting. .
I didn’t like the gap between the bumper and tips so I installed a valence.

Thanks Speed Enginering for a great product and service.
And thanks to all who posted here with your experience good or bad. It helped my install

 

Damn, That looks good!

 

i think i got them from speedway.

 

Bought spirals from speedway motors. Inserted them in the mufflers. I cut them down because they sounded funny.

 

You said that you cut the Spirals down. So which ones did you install?

 

the 2 ring.

 

So you killed the flow to quiet it down? Why not just get a set of XR-1 mufflers or go back to a catback with cutouts.

 

Didn't actually quiet it down it changed the tone and eliminated interior drone which Is what my ears can’t handle. I’m going to see what a single ring will do. Maybe put it further up stream.
True dual sound is what I wanted.

 

What valance is that ?! it looks amazing.

 

right but you could just add resonators or cats to the y pipe to effectively do the same thing and preserve flow. Sound is just energy and in an exhaust system, to change it you must convert it to heat energy. Spirals dont have any absorption material and no chambers to redirect sound and turn it into heat so it may change the sound a bit but wont quiet it down. Chambered mufflers usually do the best job of tuning out lower frequency harmonics to eliminate drone.

 

i am running Height flow metallic cats and whatever the spirals are doing they are removing the drone.
maybe back pressure bringing exhaust temp up? I have no idea.

 

I picked it up at the local pick n pull.
I got the idea from Dee Struggles on UTube.
it’s off a 2004 Grand Prix.

 

You can pop the spirals in or out in less than 10 min easily once they're fitted.

Looks good littless