Will adding the y-pipe add a louder sound to the exhaust? also I had one muffler shop put on my fm 50 series hd and it has a 3 inch inlet. The problem to me is that he installed a 2.5 inch pipe from the factory y-pipe which was 3 inch. I went to another shop to get the y-pipe put on and he suggested that he run 3 inch all the way from the new y-pipe to the muffler. Will this result in any diffrence performance wise?

 

the y-pipe will make it a bit louder yes because it will elliminate the 2 cats after the manifolds. 3 inch will perform a bit better, nothing u will notice on the but dyno though

 

y pipe doesn't have to eliminate cats

LT headers would.

Hemi or 4.7?

 

It is a hemi

 

How will it eliminate the cats if the y-pipe is installed after the cats

 

My 2008 4.7 has the cats right after the manifold down pipes. Those two then come together into the Y. You will and should not eliminate the cats.

 

well it goes headers to the cat where they combine. when you get there do what i going to do i buying a magnflow i mean bought 1 then you get the pipe more stright then you weld it into the other pipe from cat back

 

well the only way your going to make it worth your money and time changing your y-pipe is to take out the cats.... otherwise leave it as is.

 

False. (You in Canada?)

It is dyno fact that just replacing the y pipe is 10-15 hp depending on whos dyno you go off of.

 

haha thats a joke.... bet you have one of those 50 hp chips off ebay as well.... believe me.... its not worth your time unless your going to remove everything and open it right up