2012 z7 w/ pro xs 150

[bramor]

I have a 2012 Z7 at top end runs about 60 with reasonable gear and just driver in boat. When I add a 125 lb person, wont run more than 52. Why am I losing 8 mph with an extra person. Added a 6 inch bobs manual plate set at 3.5” below pad and now I only got 52 with driver only. 24p tempest...better hole shot with plate but no top end