All right, really need some insight........

[Captain Morgan]

96 chevy 2500 350(5.7L for those so inclined),
wife went an had dual exhaust put on with no mufflers! Its too loud!
I do like the added sound, but its gonna need a muffler(s). I don't like the
"poppin" noise it makes. Now on to my actual question:
Should I use a single muffler with a dual in/dual out or
Use two separate center in/center out.
My thinking is that the single will act as a crossover and equalize the sound.
The truck does have true dual exhaust, one pipe from each manifold.
Look forward to opinions! Thanks folks!

 

[sle2115]

There are benefits to both, but I typically added an H-pipe to allow each pulse of the engine to evacuate through both sides of the exhaust.

 

[Captain Morgan]

There are benefits to both, but I typically added an H-pipe to allow each pulse of the engine to evacuate through both sides of the exhaust.

Could you expand on that a little more? It is about the same cost for 1 dual in/out or two center in/out.
Trying to figure out which way to go.

 

[PackRat]

First off:
Where do the tailpipes exit? Rear dumps will be quieter in the cab, than corner dumps, side dumps, or really obnoxious side dumps in front of the tires.

Second:
What size pipe did they use? Smaller pipe is generally louder, and higher pitch, due to the increased air velocity. Larger pipe is normally more mellow, and deeper tone, via decreasing the air velocity.

If you want quiet, add an H-pipe and dual turbo mufflers. This effectively doubles your ehaust volume, and improves the sound dampening. Put the mufflers as far back as practical, as this will help to control the "pop" noise you describe.

40 Series flowmasters are a pretty good choice for someone who wants a throaty low tone, without the crack of glasspacks.

FWIW, if you want near straightpipe loud, but mufflers installed (to keep the gestapo off your back), go with glasspacks, but reverse them, so the packing vents point back, instead of forward. Installing them normally, makes things noticibly qieter, but they burn out faster.

 

[sle2115]

Could you expand on that a little more? It is about the same cost for 1 dual in/out or two center in/out.
Trying to figure out which way to go.

Some mufflers are dual in/out, but don't allow crossflow between the two sides. If it does, then you are good to go, but having duals "hooked" together balances the sound but even more importantly, it gives each cylinder pulse, the full use of the exhaust beyond the crossover. If you look at cars that are run in street classes, you will almost always find the crossover close to the headers, which gives them basically two duals to push exhaust through when each cylinder fires. Not to mention, it typically "adds" to the quality of the sound. Performance is enhanced as well as flow area is increased and scavenging is at it's best.

 

[PackRat]

Not to mention, it typically "adds" to the quality of the sound.

Depends on how you define 'quality of the sound'. Personally, I like the sound of true duals, over crossovers.

 

[Captain Morgan]

2.5"pipe from the cats back. Exit rear of truck on a 45deg angle at bumper corners, I don't do straight out at the hitch. If you ever hooked up a trailer with the truck running you know what I mean. I assumed that dual in/out Series 40 would act as a crossover. I can't find a cutaway of it to verify. Sounds like two center in/out and a x-over may be in order. Thanks folks!

 

[sle2115]

Depends on how you define 'quality of the sound'. Personally, I like the sound of true duals, over crossovers.

Deeper, richer tone, no cackle. I think cackle is best left in the hen house, but that's just me. I prefer a deep rumble, throaty sound over all that popping, and performance is enhanced as a by product. I wish I still had access to a wheel dyno, was cool to make a change then note it's affect. In my cars, the crossover always made better horsepower and often times was actually higher than with open headers. Of course these were street driven cars as well, not all out racing stuff, but the torque/horsepower curve was better with the crossover.

 

[Captain Morgan]

I'm with you on the sound! I don't like glass packs or anything that pops and cackles. I always liked the flowmasters it's just been awhile since I have installed something besides OEM on a gasburner! Thanks I appreciate the help!