When you run a trip boat the center engine can't really hook up. The center throttle will always be about 1/3 the throw of the other 2 and the rpms will be the same. On the 47 you can see the center motor just throwing water into the air until the boat nears top speed. Then you have to throw more throttle at it, the tail lays down, and you run up the last 7-10 mph. My buddy's 47 with trip 670's and Bravo XRs ran right at 100 mph but still needed a little tweeking. The best set up for that boat is twin 1000 hp or so engines and 6's. With that you could run over 100 with AC, genset, head, etc. and your 8 closest friends