Definitely leave the ring in the turbo. Not only does removing it make no difference on performance, but you risk hitting a vane on the impeller as you try to dig out the snap ring. I tried the air intake hose with and without the airflow-shaping insert, and put it back in. The new trucks are (finally) like buying an appliance, a finished product. Not a kit to be finished/modified any more. Sure some owners always want more power, but the downsides are potentially big so I have left my 2013 stock in power. It has enough for my uses, with 352 HP on the dyno.