I was reading on the internet, saw some info on a cone in the turbo that you could remove, what for, does this help milage, performance, etc. Looking for info to begin a project.

The silencer ring removal will gain you a lot more turbo noise... that's about it.
The TAG or turbo air guide members have mixed experience about

for an 00 get a set of DD2's (injectors) and an EDGE Drag comp Box. that will net you an extra 190RWHP... oh, and get an HX40 turbo while you are at it... or a bell USB-1 or a Dodgezilla... or a Jammer turbo

Here's how to remove it:

http://www.turbodieselregister.com/forums/showthread.php?t=93566