I currently have a #16616 lightning style SI/DO cat-back on my 4.6L. I'm wanting to replace the factory Y with a X-pipe into dual SI/SO Spintech Pro Streets dumped, keeping the pipe size at 2 1/4" to reduce the loss of my low end power.

I'm just wanting a little more sound and the added performance of the X-pipe.

Will I see any performance gains or will all my low rpm power move into the higher rpms?

 

stay with the magnaflow and get an x pipe and get a DIDO muffler or it will do nothing to get an x pipe if you go back to a single inlet muffler

 

so a Di/DO is better than 2 separate SI/SO's? I would think that 2 11" SI/SO Maggies would sound better than a DI/DO 14" or 18"?

 

they makes an 11" DI/DO...

 

That's a negative on that 11" DI/DO Maggie. It has the X-pipe built in and I don't want that. I want the standalone X and then two SI/SO 11"s, that way I can get the X closest to the cats as possible and still keep the mufflers not right under the cab minimizing the drone.

 

if your worried about minimizing drone then why would you want 11" mufflers in the first place? smaller muffler = more drone/sound. maybe get 14" or 18" mufflers for better sound reduction...

 

I have a 18" SI/DO right now and I just want more. At the same time though, I do have passengers sometimes and it's nice to comfortably carry on a conversation or not have to have the radio at crazy levels.

 

zero droan out of my setup- 2-2.25" siso 4x9 magnaflows-x-as close to original y-pipe as possible-phil

 

I have a 11" dido magnaflow, no internal X.