I currently own and run one of these motors. I had the same thoughts as well so I called Curt at Fastrax Union Bay. He said that motor has the wrong port timing to support a turbo system or even stand a chance at surviving with a turbo system.
They also are design to run twin pipes and will not flow correctly with twins hooked to a turbo.
My intention is to install my 900 in a pro chassis and have a Curt help me fabricate new slip twin for it. A true 195 hp big bore in a pro chassis is my style of riding.