Hey guys, Ive been in the diesel world for about 5 or 6 months now and love it.. I get bored easily with my vehicles. I wanted to run a straight pipe turbo-back exhaust. Love the sound and i know they say it increases mpg's and power. Here's the question. I know a bunch of people run 4 inch but obviously I dont want the same truck, so honestly just wanted opinions and any extra info on 4" versus 5". Any information will be great. Thanks!

 

they usually have the same 4" downpipe and then turns 5" about halfway back on the truck, i personally think the magnaflow 4" downpipe fits the best. silverline makes a 3.5" downpipe that fits easily without having to push the firewall as far!
as far as mpg you will see very little benefit on a stock truck without programming. stock parameters look for certain amounts of exhaust back pressure for the vgt and if you lower EBP the pcm will add vgt duty cycle to make up for the loss.

 

so it'd probably be better to run a 4" rather than a 5"? I love the sound of both but I wasnt sure if running the 5" if it will make it run any different or do any harm. I don't to mess with anything in the computer just for the sound ya know? Truck runs awesome as it is but I was looking for a little louder and better sound, but sound isnt worth doing something to my truck Ill regret.

 

5" won't hurt anything just deeper tones and fits worse

 

Save yourself the headache trying to fit that 5" just get a 4" straight pipe. Thats what I have and love it.

 

id just do a 4incher like everyones saying, probably cheaper too !

 

I just installed last friday the 5" turboback MBRP plm exhaust. It fit perfect, no problems, no hassle. has the 4" downpipe but everything else slides together real nice. LOVE the sound, and paired with Livewire TS running Vivians Looney tune its a real head turner Goodluck!