I googled Silencer Ring, and went to Wikkipedia as well. Basically as mentioned above, it just "silences" the turbo, it cuts down on the while. All I can figure is that someone complained to DC about the noise and this is what they came up with. It is simple to remove. I read the posts in here, grabbed a work light, a screw driver and a scribe and away I went. I removed the air tube from the air box to the turbo, then used the flathead screw driver to lift up one end of the snap ring holding the ring in place. Once I had an end free I hooked the scribe under it and slowly worked the scribe around the lip of the turbo until the snap ring popped out in my hands. After that I just grabbed the silencer ring and slid it out. I stil have it in my tool box incase I decide to put it back on but honestly I could hardly tell the difference (I have a stock truck except for the amsoil drop in air filter). The only time I can hear the turbo (more than before) is on cold days. My wife cant tell the difference, I actually had to explain to her, "see hon, the turbo is louder right now, hear it? thats because I took out that ring thingy I told you about".
She still cant tell any difference. The only reason I kept it out is that I am hoping there is a tiny increase in airflow into the turbo with the ring removed.
I have not noticed any appreciable increase in mileage or power with it out, just a little bit more noise from the turbo.