i currently have the 3" factory exhaust turn into straight pipe i have been thinking of going to a turbo back 4" exhaust. how much will this drop my temp down? i allso have been think of 4" duals out the back will that make any diffrance?

 

Upgrading to a 4" turbo back exhaust should decrease your temps ~150*. Don't waste your money on duals , unless you want the look. They don't flow any better (actually a little less) than a single 4" does and they cost 1/3 more. I do have to say, they do look cool though and then you are also an equal opportunity offender. Smoke both sides baby...

 

Get ya a good 4" Turbo Back Exhaust System there are tons of brands to choose. The 5" Systems sound awsome on the 12V Cummins.

 

I agree duals look great but do nothing for performance, I run duals and like the smoke equalized out each side. IMO the tone changes for the better too.

I am not sure IF you would see 150 degree drop in temps but any flow improvements on the 12 valves or any diesel is good.

If you like to hear that cummins straight pipe it, personally I love the sound of a straight piped 12 Valve.

 

the 5 inch does sound mean on 12v's

 

I too have duals on my 2002 CTD. It's just to sex it up a bit, nothing more. The drop is somewhere between 100 and 200 F so 150 is safe to say. I personally don't like straight pipes because of the drone BUT a well tuned (or BOMBed) 12V has have a better sound than a 24V anyways.

 

I run me an exhaust thats 4" turbo back to performance muffler, then outta muffler up over axle is 5" dumping down/back with a nice shiny 6" tip. sounds good for me. ran straight pipe on old truck, tried it out with this one. i mean im still young and like noisy trucks, i just got over the drone of a straight pipe, so i pieced my exhaust to try and make it as loud and obnoxious to anyone outside my vehicle while pleasant to my ears in the cab-

 

does a 5 inch kit start at the turbo as 5 inches? how big is the exhaust up there