I'm going with 3 inch duals. How loud???
 

Ok so i'm gonna try a true dual 3 inch over the axle with 23 1/2 inch long dynomaxx bullets. This will go with my ported mac's with the ball flanges already removed then out the back with 4 inch pipes!! and now i'm wondering how loud this will be compared to my exhaust i have now which is a 3 inch y no cats to a 3 1/4 inch ravin muffler to 4 inch pipes out the back. BTW i just ordered a BMR panhard brace bar. The reason for this change is so my new A/S STG 2.5 5.3L heads and my ported BBK 80MM TB and ported LSX to 80 MM will have no restrictions

It will be a little louder and sound alot better. If you use an Xpipe It will help to quiet it down a bit, plus make more power. If I were you I would upgrade to some long tubes before I did duals! You need them!!!!

Brad

It will sound badass, it's really not all THAT loud compared to say headers, no cats, and something like the loudmouth on a Y-pipe setup. The X-pipe crossover, plus the fact that it's a good bit deaper makes it sound a little quieter even if it's really not. FWIW: I think the macs will serve you just fine, obviously LT"s would be better, but it's largely accepted that macs can support plenty of power w/o holding you back very much at all.

Try www.ls1sounds.com for some helpful info.

They are okay for a stock motor. He has a tsp 231/237 so the LT's will definately help out.

Brad

I had duals with x pipe and bullets dumped. I could not stand the noise because it was too loud. I cut them out and put some dynomax ultraflo mufflers in. It's still kind of loud, but better than it was.

Im changing my duals back to a cat back system. Theyre so deep that I cant hear my cam lope. At idle it sounds like an LT1 cause its deep and loud. I still havent heard my car from outside before while someone else is driving and romps on it. One thing that I like about the duals is that it has a 360 degree sound. Weather you ahead of me on behind me your gona hear me. With a cat back all the sound is behind you. And will 23 inch bullets fit? Its gona quiet it down a bit more. IMO 18's will be just fine.