That was a good explanation drew. I was too lazy to type, but the article in the link I posted above agrees with 100%. LOL...

 

So what exactly would be the ideal performance exhaust for our Hemis.......what headers, X - pipe, aftermarket cats, mufflers (semi loud turbos or straight throughs) , shorter exhaust exiting before rear tires or out the back ??

 

{ bit late on this.... like 3 years but its here....}

short tube , long tube ?
One does more for the low end from what i remember.

Spent 8 years in an exhaust shop and got to play with alot of other peoples toys.
Im personally a fan of equal length tube headers and pipes before and after the mufflers.
Not sure what that does in the terms of scavenging but everything I ever put exhaust on from stock cars to trucks with equal length pipes sounded awesome. The stock cars sounded like high end Indy car engines when collected into a 10" long 3" megaphone. Evenly spaced notes of power.

My current truck has true duals and I hate it because the tone from one side to the other is so different due to the driver side having so much more pipe before and after the muffler .

What I want is a 2.25 equal length pipe to a good Y and 2.5 or 3" single out. With or without headers. Still trying to figure out exactly how to get it done on this truck since i no longer have access to a bender, and pre-bents are so expensive whether mandrel bends or not.

Dont know if that helped you or not but if your gonna have it built or build it yourself this would be something to consider or even research a bit into.

 

my tru-dual hybrid works just fine for me...

 

I don't see how it would be a problem, the LX cars are almost true duals from the factory (minus the DI/DO muffler). All the catback kits are dual mufflers, the Mopar kit I just put on my Charger is dual muffs with an x-pipe.

 

Many years late, but for the record:
I had true dual ran on my 4.7 and it gave me an increase in power and better fuel mileage. I forget the pipe size offhand, but I had the shop continue the size of the pipe from the cat outlet pipe (at least 2.5" but not more than 3").
I'm thinking of trying the H pipe to see if it makes a difference or not.
As to keep the pipes from knocking together because they are so close they did weld both side together which cause the driver's side exhaust manifold boots to shear off. Lesson learned and will make sure there is a flex joint to keep the pipes from torquing during heavy load and/or heavy acceleration.
Given what I read here, I think I'm going to look at wrapped headers also. Anything that gives me more power with better fuel economy is worth trying.
I don't have MDS so it is not an issue for me. Given all the different vehicles I have driven, MDS is bad at highway speeds unless you live in an area with completely flat terrain. It is going to kick on and off as you go up and down sloped terrain.