Does anyone know what true duals would do to a Hemi? Would it be better or worse than a cat-back system? I had a cat-back Flowmaster 40 with turndowns on my 98 318. It sounded alright I guess, but I never really noticed a change in performance. I wasn't loud enough to me either. Some people tell me true duals are the only way to go to increase performance, but then someoneelse tellsme that you lose a lot of low end torque with them. I just don't know what they would do to a Hemi and I figured someone here would have some advice. I do know that I'm switching over to Magnaflow. I've listen to a few Hemi's with them on Youtube.com are they sound really good to me. I also like the fact that they're made of stainless steel, have a good warranty, and have a flow-through design. Thanks.

 

All the mufler experts get on here and preach that the only way to do a dual ex system is with a H pipe, if your hemi is a 4x4, thiers is no room for this, the left ex manifold has a longer way to go into the right and the y pipe.

I have a dyno max ultra flow on my hemi ( 2nd mufler replaced under warenty ) 2 in lets two out lets X in the middle.

The y pipe was cut out and the two ex pipes exit out over the rear diff and to the right.

as for as muflers go, I don't want any one to go with dyno max, mpg has really improved, power wise, no real gains.

THe stock ex system, Y pipe, mufler and resonater ( my hemi is a 2500, no resonater ) is restrictive, opening it up will improve mileage and power.

If you keep the y pipe, a less restrictave mufler and removing the resonater is the best compramise, if you turf the y pipe and go with duals, you have to resarch muflers.

My truck is a 6sp manual, so it was never really quick to begin with, consdiering I'm not a fan of dynomax, running my set up has really improved the MPG.

 

Mines a 2WD. I have looked under the truck and I think the best way to run duals would be to cut off everything right behind the cats before it goes into the stock Y-Pipe. Then using the two separate exhaust pipes run the duals. Then put in a small H or X pipe in there somewhere.Probably would have to put the two mufflers side by side on the passenger side of the pickup because there's not a lot ofroom on the other side. Then you can do whatever exit you want from there. Turndowns or a side exit wouldn't be a problem, but I don't know about exitingout ofthe rear of the truck. The spare might be an issue. Doesn't really matter to me I prefer the pulsing of turndowns. None of this idea is proven to work so don't take it to heart. Just an idea.

 

Pacesetter Long Tubes here, then to the individual cats (moved back 18" to allow for the extra length of the headers), into a "Y" pipe (not the Pacesetter one which is better than what I have, but not the factory either, just a "Y" that I could cut to fit that I picked up at a local Meineke). From the "Y" I'm using about a two or three foot pipe into the single input on a Flowmaster 50HD muffler and out the dual outputs, then to my two 18" stainless tips.
Fantastic sound, pretty good flow. I plan on changing to a Cherry Bomb either Vortex or Extreme muffler when the Flowmaster goes. Even with the cats and a fairly restrictive, chambered muffler, it's not too restrictive. Besides, on a heavy *** 4x4 you need a little backpressure for the low rpm torque.
The key was the headers, when I added them to the existing CAI, Cat-back & tuner they really "woke up" the truck, especially from about 2200 rpm's and up, not to mention picked me up about 1.5 mpg's as an added bonus...

 

I have true duals on my hemi...I honestly cant tell you how much I gained from them because I never had a before/after dyno. I used a flowmaster 50 hd muffler. later this summer I will be having an AT 3030 muffler installed, they sound meaner and flow better than flowmaster...You can put an H pipe on a 4x4 but an X pipe could be a little hard

 

I have a question.Does the hemi need back pressure or will it run good with true duals? I Know the chevy 5.3L needs back pressure or it will kill all low end power. So do I go with the 2-1-2 special or true duals?

 

That answer depends on who you ask. lol......I have seen enough to beleive the hemi dosn't need backpressure

 

I have true duals on my 04 regular cab, 4x4 hemi. They run into 12" glass packswith 3" turndowns that are about 2 foot long. I did lose a little bit on the bottom end, but it sounds soooo much better, and top end seems to have increased a little bit. And if you are wanting loud, it is most definitely the way to go and honestly, it is not that bad in the cab either.

 

I wonder if a set of long tube headers would help keep that bottom end power? Having a loud truck doesn't bother me as long as it's not way too loud. I don't think that will be a problem though.

 

I think that's backwards. From what I've understood, LTs will give you more top end, but take away a little of the bottom end.