I ran a 5x11 14" magnaflow in place of the stock muffler this weekend with no cats and stock manifolds. It sounded great, but drone at 1800-2000 was unbearable even with the windows down.
I get headaches easy, so i need it quiet like stock.

Im gonna order 2 more magnaflows and give them a try, maybe a 22" 5x11 and a 30" 6" round muffler. And if i have room, ill add this 14" 5x11.

We shall see how quiet it can be. And im sure the turbo will kill a good bit of noise. I know my STS with that 14" magnaflow was pretty quiet.

 

Now the real question is do you put the round muffler first, and then the ovals? Or oval, round, oval? Or oval, oval, round?
So many options!!

 

Round, smaller oval, larger oval.

 

Think the smaller ones will kill the sound and the larger one last inline will kill any drone?

 

I've switched up exhaust a million times, and now I've got a smaller Magnaflow, so I know how bad it drones. But, I've found it to work better with the bullet(s) before the larger (oval) case muffler, if you're wanting to deaden noise/drone. Resonators are behind the mufflers in a lot of OEM applications, but as far as aftermarket goes, I like a properly-sized bullet in-line, in front of a larger case muffler. Seems to work for the whole quiet deal.

 

So a 30" bullet, 20" 5x11, and a 14" 5x11 in that order should be silly quiet.

 

Yeah I really like how the corsa doesn't DRONE in the cab much at all, it's just a really loud muffler so you're going to hear it when stalling up the converter in traffic...I love the sound it's just a little loud when driving business clients around, etc. I know it'll be ridiculous with LTs. Maybe a large powerstick before the corsa will tame it some? We'll see.

 

Is it the actual sound from oustide your truck that keeps you from being able to talk on the cell or is it the drone in the cab? I am going to have a funky looking exhause setup later this summer. Lt' 3" pipe to Magnaflow X to 2 4x8x16 bassani's and have 2 drone tubes put in to move the drone to a higher RPM to overcome the in cab noise issue.

 

I thought if you want it quiet, the further back the muffler the better?

 

I'd do the 20" case last, after the bullet (1st), and the 14" (2nd). Truth be told, it probably doesn't matter that much, but that's just me. Just make sure you get the biggest O.D. bullet you can find, or one close to it. Regardless, I'd bet it would turn out stupid quiet.