Afternoon patrol heads

So I'm straight piping my truck to beef up the sound a bit. I've already been for a drive with the rear section (with muffler) unbolted from the front section. With the turbo its not obnoxiously loud ive found.

Being diesel, and turbo, back pressure isn't needed is my understanding. But for whatever reason will I need to give it a tune once the new section of straight pipe is in?

Silvertop TD42 with aftermarket turbo.

Cheers Dylan