There are a lot of variables there. What Nozzle, Nozzle size, impeller size, impeller make, Hi-Helix, pump brand, pump model, suction housing, intake, loader. Just about every change you make to the pump will affect those numbers.

 

I figured that, I was hoping for some basic figures. Well i'll throw this out. Dominator pump w/ Place diverter (standard) a/b Impeller

 

it also depends where you're taking the pressure reading...

VERY roughly, i see about 135psi at 4000, about 200 at 5000, about 270 at 6000, and about 310 at 6450. emphasis on the "about", because these numbers tend to oscillate a little and i don't stay at 4000, 5000, or 6000 very long. this is with a 3.125 nozzle id...
knowing the pressure and pipe i.d., you can calculate flow rate.