Due to state inspection, I have to put a catalytic on my exhaust or i won’t pass, so ill go do the inspection then go catless the same day afterwards.
Now that im going to do a cut on my exhaust system, I was debating on trying something new.
Currently i am running a catless 3 inch y pipe exhaust. 4.8 220/220 cam, somehow i feel its too much flow, i was thinking about running a x pipe 2.5 all around to increase backpressure. Would this set up be efficent ?

 

I'm no exhaust flow expert but I see it making no difference. Back pressure is not an issue here, a free flowing exhaust is going to make hardly any at partial load, like less than 2psi if it's got a lot of bends and small tubing diameter. Then even at full load on a system that is already 3in on a little 4.8 engine it's going to be minimal back pressure. Making more back pressure isn't going to help you any, infact that would be the same as hurting the flow of the exhaust.

A turbo or maybe like a diesel application you need to think about exhaust back pressure differently but here this is not something to even think about.

 

Guess ill just stick with my y pipe if its minimal difference then, thanks for the feedback!