whos got the highest boost out of a stock impeller

[winfred]

i have my sn92 pulleyed to run 41k at 6500 rpm and logged a few kpa over 7# this evening from the map sensor of my ECU, this is with a water to air charge cooler in the way on my SOHC 2.8 inline 6 bmw, i am thinking the upgrade impeller may be good for 2# on my set up if its normally good for 1-2# on normal applications

[Buck-Strickland]

I have seen 7# with a HO impeller @40K, also through a A2W intercooler on a 406cid Chevy.