I've got 4in straight through muffler and exhaust system, I'm thinking about adding in a muffler delete pipe. Will this make my turbo louder at the pipe? And are there any pros / cons to making the exhaust a straight piped with no muffler ?

 

Running a straight pipe will increase the "turbo-noise" at the tail pipe. Especially if you are running a Magnaflow muffler now, they tend to muffle the turbo quite a bit. I have a 4 inch downpipe into 5" back to 6" stacks and it sure does rumble! It can get a bit annoying if im trying to have a conversation while driving around with someone on the phone or even in the cab. Especially the drone on the highway, but it wont be as bad with a 4 inch system exiting behind the rear wheel but still may be noticed.
I *personally* dont see any 'cons' of running straight pipe.... I dont like most of my neighbors anyways