Gettin ready to build an exhaust system. Was looking at sizes today and I can go with a 5" or a 6". What are the + and - from both over stock? Am I going to loose low end from now back pressure? What about sounds?

Any pics out there?

 

I think if your over 500 hp then you should go with 5" and if your over 600 you should go with 6". Im pretty sure that is what everybody has said. At least thats what they told me lol. And under 500 you can just stay with your 4" stock and just put a high performance muffler and be just fine.

 

i have 5 in and i am happy with that lowered egts some

 

You don't need backpressure, and excessively large exhaust doesn't cost power because it's depriving your engine of needed backpressure.

Excessively large exhaust reduces power because the flow isn't exiting smoothly. If the transitions are gradual enough (not more than 20º angle) then there's no such thing as an exhaust that's too large.

That's rarely true-- hence the reports of power loss with 5" and 6" in some cases.