0
Size small and BP has 6 plates (5'6"-6'1"). For reference, I'm 5'10" 165lbs and it fits; would probably fit up to 180lbs depending on build (size small is kind of misleading; more of a medium IMO).
I used the BP only for 2-3 years of trackdays. The rest of the armor is brand new. All functions, nothing missing. Pickup weekdays in Hopkinton MA. $30
http://www.highvelocitygear.com/juggernaut.html