I've kinda been shopping around for a bigger exhaust system and i just kinda wanted to know the best size to run? most everyone says to go with a five inch? is there that big of a diffeernce between a five and six inch performance wise?

 

again, lay off the bold, just makes it harder to read..


most guys run 4" thats plenty till you get upwards of 550 hp. Some even say they loose a few hp when the go to the 5". But the 5" does sound deeper. Just personal preference. and 6" is WAY to big to fit under the truck.

i would go with a 4" if i were you, and put a big tip on it or even stacks.

 

Brian is right, and I wouuld reccomend the 4" as well.

Lots of guys get cought up in the bigger/newer is better, but 4" is enough for almost every CTD on the road, as far a coolin capaciy. If you want the sound of the 5" that's cool, but you don't need it.

And where you are at you most likely won't see a performance increase with the exhaust. You will see EGTs drop, and if you are ovefueld you can make use of more of the fuel you are injecting. But you don't sound to overfueld.

 

5" may give 25-50* lower EGT's. I've toyed with going to a 5" system but never really saw the need. My EGT's have always been same or better than others at my different HP levels. I still run a 4" and have no plans to change.
My TIP (back pressures) are excellent and with Twins, EGT's concerns are no longer an issue on the road.
Other than prefering the sound of a 5" system, I see no serious performance gains and no reason for going that big. JMO.

RJ

 

k.... cause i was actually thinkin of runnin 4 inch duals?

 

We made 832 RWHP on a 4" system with a muffler.

Doug Smith