From doing a little bit of research I've seen that when using nitrous your exhaust system means a lot as far as being able to get the "most" out of your nitrous I have a basically stock truck and I plan to start with a 75 shot and work up to 125-150, will be tuned by nelson performance every step of the way. but as far as the exhaust goes, I'm just wanting opinions of what would sound good and not be overkill and lose tooo much low end. I'm thinking Texas speed longtubes and ory, to 3.5'' moroso spiraltech muffler and from that to a borla muffler (idk series but it is straight through like the moroso,) also 3.5'' to a factory location 4'' tip. As far as a horsepower torque standpoint how would this exhaust perform vs. A 3'' counterpart while under 150 shot and na thanks in advance 2002 5.3

 

i almost want to say that a 3.5" might be a little too much for the 5.3l but i may be wrong. i wouldn't worry about putting 2 mufflers on there just get one that's like in the 16-22" case length. i have the magnaflow 18" case and i think it would be **** with long tubes but that's just my opinion.

 

I have longtubes and a 24" magnaflow on my truck and it is super quiet. I am sure the 18" is only a little louder. With a 5.3 even fully built you are looking at 300-350rwhp. A single 3" won't become a restriction until 400+HP. A 3.5" single will be more than sufficient with a 150 shot on top. You might consider 1 7/8" primaries on the LTs if you think you might go bigger power later.

 

no need for dual mufflers or 3.5", the 1 7/8" primaries will be good with nitrous, and as you mod they'll benefit you even more.

 

I would have to say a "fully built" 5.3 would make a good bit more than 350 at the tire...

 

I agree a fully built 5.3 with high end parts can make much more than 350, and I appreciate the responses. I do plan to make far more HP in the future but for now the funds are pretty much exhaust n nitrous. But basically when I flip the switch I want to get every bit of advantage I can from the n2o, that's why I was thinking larger dia pipe after the 3'' y since a 150 shot is ( guessing ) 50% more air coming out the air pump/engine I'm going to generate more backpressure, and as far as sound what is the effect of running 2 mufflers on one pipe vs one. I don't like cackle but I do like fairly loud

 

3" all the way will do it.

 

3.5" should be plenty for what your doing.