In a related post an HX 35 has a 3" cast elbow, going to the 4" DP, is it worth having a 4" DP if your restriction is in the turbo?

 

Dont know if im helping matters, but the way I see it is the quicker you get to the big pipe, the better flowing your exhaust will be. Like why would you put a 4" downpipe on a 3" outlet turbo, or a 5" on a 4" outlet turbo.
That elbow isnt really that much 3" when you think about it...
I guess stans downpipe and other downpipes without the cast elbow would flow better than a 2nd gen 4"...

 

in my eyes it doesnt really matter if its just the 3 inch outlet. i mean yea it probably makes a tiny bit of a difference but hey its still going down the 4 inch about 2 inches later judging by my second gen down.

 

Reason I ask is that I have a Pacbrake which is about 2.5 inch dia. and I feel it may be a restriction for me in the near future.What do you all think? The up side is it is a nice adapter for something like a Stans and we all know these trucks need braking help.Currently the Pac goes to a 3.5 Banks exhaust. Should it stay or go? Lookin at 350 horseys this year.

 

sounds like a <---choke
try it and see how your egts are... But if you can get a 3" brake, do it... doit.

 

How large is the exhaust flange on the turbo? See what I'm getting at? I feel that the faster you get to a large pipe the better. As far as NOT doing it because the out let is only 3"... Well all that exhaust just cam through that exhaust flange... Bet it flows less the the 3" outlet