Difference between 4" and 5" exhaust
 

So I'm thinking about going

5” is bigger, therefore cooler!

Lol , what's the plus side ?

How much HP did you add?

Edit: You said tow tune so minimal HP increase (30?), I read but didn't comprehend. I'd say keep the 4 inch. 5 inch exhaust isn't going to provide much benefit. Possibly it'll slightly lower EGTs and a different exhaust tone but you would be changing it just to change it in my opinion, which you could certainly do. The turbo outlet is 4".

most 5" kits are still 4" until a couple feet after the downpipe, they sound better in my opinion, but beyond that there is no benefit to be gained from them. Changing the downpipe to a bigger one without all the bends/restrictions in it would be a good idea, it's not the easiest thing to do though, honestly helped having 2 guys when doing mine.

sometimes changing exhaust size can lower your MPG.

[QUOTE=kper05;18635437]How much HP did you add?

Edit: You said tow tune so minimal HP increase (30?), I read but didn't comprehend. I'd say keep the 4 inch. 5 inch exhaust isn't going to provide much benefit. Possibly it'll slightly lower EGTs and a different exhaust tone but you would be changing it just to change it in my opinion, which you could certainly do. The turbo outlet

Is there any difference from a dpf delete racepipe to a full delete exhaust?

I believe a lot of the factory piping sizes are 3.5" not 4"

[QUOTE=bobcat67;18635915]I believe a lot of the factory piping sizes are 3.5"

if sound is what you're after, a 5" with or without a muffler will sound the best, if you do a lot of towing, I would recommend a muffler. Sometimes there is clearance issues with 5" over the axle if you have a gooseneck plate, 4" sounds good too, I'd highly recommend a down pipe though if you're really wanting the best sound/least restriction, although there is minimal restriction if any at your horsepower levels with any of the systems including stock with the truck missing the heavy parts

[QUOTE=bobcat67;18635926]if sound is what you're after, a 5" with or without a muffler will sound the best, if you do a lot of towing, I would recommend a muffler. Sometimes there is clearance issues with 5" over the axle if you have a gooseneck plate, 4" sounds good too, I'd highly recommend a down pipe though if you're really wanting the best sound/least restriction, although there is minimal restriction if any at your horsepower levels with any of the systems including stock with the truck missing

the down pipe is what hooks up at the back of the turbo and goes down, the factory one is kinked and bent in a few places, after market ones aren't. That being said they're kind of a pain to install. The resonator on the factory exhaust is see through so it doesn't cause much if any restriction. Other than sound there really isn't much gain to be had from what you currently are running

:-X22 Thank you Sir

This is contrary to what's been suggested earlier (additionally it comes from an unknowledgable source), but if sound is what you want then stock is best. I seriously dislike noisy pipes/ trucks.
And while I'm pleading my ignorance I'll also admit to my avoiding trucks with lifts and/or emission deletions.

Come resell time I wouldn't touch any of them.