I'm going to get a new exhaust installed next week. I'm not sure if I should get a 4 or 5 inch. I do know I want a muffler. I have the juice/attitude and the egt's get hot, real hot! I can hit 1350 before the 1/8th mile. Since I want to run a muffler should I get the 5 inch? Will there be any difference in the egt's between the 4 or 5 inch? I know the 4 inch will handle the horse power I have. I'm wanting it to stay as cool as possible with a muffler. Thanks for the info.

 

I don't think you'll notice a difference in egt's going to the 5, I had a 4 inch downpipe to dual 5 inch stacks, and now I run just a straight 4 inch and I see no difference.

 

do the mbrp 4" from the DTR store. i got mine with a tip on sale for 330$. itll give you good sound and itll be better than the stocker

 

Does that include a 4" downpipe?
Also how loud is it and do you get any in cab drone?
I don't want a loud truck just free flowing.

 

5'' is a tiny bit cooler egt's, but youll lose a little hp due to less back pressure.
Very slight on both ends though, but 4'' with a free flow muffler will do you fine.

Coarse I love my 4'' straight pipe, and I dont have in cab drone cause the engine is so loud. People in the back seat say a little dif though

 

Will a 5 inch with a muffler give me the back pressure I need?

 

the turbo provides backpressure so there is no worry for your application about backpressure,
any muffler you put on a 5inch system is gonna be straight through, meaning you can look in one end and see straight out the other, the idea of a larger exhaust is to eliminate any backpressure that would have been present in the stock system

 

dont listen to anyone that says you need backpressure on the turbo cummins, that claim is down right rediculous. I would go 5" all the way. You can get a expandit exhaust for $300. I cant see the reason to spend more on an exhaust system when the only difference is the clamps.

 

There is a shop near me that will install a 4 inch stainless exhaust for 355.00. I didnt ask about the 5 inch. I think i'm gonna do a 5 inch... thanks for all the help!