Moved to the Custom & Mods section. The Turbo section is for the models that came from the factory with turbochargers and I'm pretty sure that installing one of those would involve replacing the whole engine and significantly altering the frame. Besides, the rest of your post fits Custom & Mods better too and your bike is pretty customized already.
BTW: Welcome to the forum. Please add your location to your profile and your bike's model and model year (NOT year first registered) to your signature (see Forum Settings link in my signature) so that you don't have to remember to tell us every time and we don't have to keep asking when you forget.
The top speed of a CX is limited by gearing- not power. My only guess to fix that is if the final drive of the 650 is a smaller ratio- assuming it can retrofit to a 500 swingarm or 650 swingarm to 500 frame. Then look to tweak power.