Ok so I think I've settled on a set-up.....tell me what you guys think...

Dynomax Ultra Flo X muffler dual 2 1/2" in/out w/ built in x pipe just after the cats, to a Flowmaster dual 2 1/2" to single 3" y pipe, with a Summit 3" to 3 1/2" x 12" polished ss slant cut rolled edge tip terminating roughly 1 1/2' before the rear axle

 

Sounds good but I'm curious why you are going single pipe exit by adding the y when you have a dual out muffler. Saving money that way?

 

Yeah I was puzzled by that too... I wasn't sure what to respond when I read that after he posted it.

 

TLT008 your math is flawed. The formula you used is circumference of a circle. The one should have used is radius squared x pi, that is for area of a circle.

EX 2.25" pipe would have a radius of 1.125" so (1.125 x 1.125) x 3.14 = 3.976 x 2 pipes = 7.952 sq" you then work the formula backwards to find the single pipe size. (sq" divided by pi) then find the sq root to get the radius then multpily by 2 to get the new diameter

7.952 / 3.14 = 2.531 and the square root is 1.59, so 1.59 x 2 = 3.18"

So the optimum single outlet size would be between 3" and 3.25"

 

Mig/Truck The reason I'm going to a single pipe from the dual out muffler is to reduce the pipe down to optimal size and build some back pressure. I'm only using the dual in/out muffler for ease of transition as it is the same size pipe(2 1/2") and I wanted an x pipe. I might change the set-up to run a traditional x pipe and a 3" muffler instead but running dual 2 1/2" pipes isn't really an option.

O5Red Thanks for chiming in w/ that equation. I suck at math and tend to over simplify things sometimes.

 

I can tell you that I have been running MBRP SI/SO with the 3.5 inch pipe. It is 3.5 from the cat back to the tip. I tow quite often and haven't noticed any loss in low end torque. I also love the sound.

 

never add an X pipe when running a single muffler. Honestly, i dont know what would work. Running the 2.5" DIDO dynomax muffler and putting the Y pipe and stay 2.5" out, or upgrade to 3" out. Never really heard of anyone putting a Y pipe to stay single out when your getting a dual out muffler.

 

Yeah...Im lost man. Wouldn't that create turbulence in the dual to single part?

 

yeah I don't know what the eff to do really now........have had too many thoughts running through my head and realized after i typed that last post that an x pipe didn't really make sense if I'm going to run a single pipe. I might just do LT's at this point and run it all back to dual 2 1/4" pipes. I would upgrade my cats too but then that opens the door to what cats to use. Anybody hear anything bad about pacesetter LT's? What cats should I run if I do those or should I just run no cats until right before I have to smog my truck?

 

If you want to do it so it will last... I would get dynatech Lt's and maggie hi flows. Then into a muffler of your choice. I would pick a quieter muffler becuase it will be very loud with teh Lt's and hi flows if you went that route. For example... I have a 14" si/do maggie. If I were doing lt's and cats, i would put an 18" on so it would be loud but not crazy loud.

 

well i can tell you my pacesetters are awesome but one piece of advice, get the ceramic ones. i got the painted long tubes which i absolutely love but wish i had the ceramic coated. rust sucks! the paint peels off quite quickly. i also have maggie high flow cats that freakin rock.

and yes it will be much louder with lt's

and yes the power is much better!

 

agree with the ceramic coated pacesetters, I have had them since spring, with the 3" maggie high flow cats and so far they have been good to go, no rust, cracks, warping or leaks, just loud. I had roughed up the passenger side pretty good during the install but still no rust, it did take off most of the coating but other than the scratches they still look new.

 

That right there is a very good suggestion for what you should run

 

all this technical talk, yet no one has discussed the most important things-
static pressure
velocity pressure
total pressure
and how these things affect performance
i/m all ears...

 

anyone want to talk about the static pressure regain method?what it does ,how do you achieve it-ie
2 1/4" dual pipes from manifold into 2 1/4" x pipe- into 2 .5" intermediate pipes into 2 1/2" mufflers with 2 1/4" tail pipes