If you are looking to make an 800 twin run 110mph or higher, you are looking for somebody that needs to know more than clutching and/or gearing. You either need a magician or a reality check. An 800 twin running over about 105 is doing about as good as it gets. After that, you need to start thinking 800 tripple. The 800 twins are about torque - the kind that feels like you are getting your arms pulled off - not top end. For proof of the difference in power between a 600 and an 800, look at drag strip times. If that doesn't give enough proof, ride one of each. I doubt seriously if you would still be questioning the validity of an 800 after that experience.....