I know one guy from Austria who has mad skills in turboing E30's
have a look at his machine
BMW e30 m5 turbo ......austrian fastest
[ 3er BMW - E30 ] - www.BMW-Syndikat.de [Fotos - Bilder - Stories]
Its pushing 840 bhp out of 22 PSI and is capable of ~1000 bhp @ 26 PSI
he also has a methanol injection for his FMIC, runnning with nitrous and also a fuel catch tank.
He has got his email adress published in this photostory, so I think its ok to hit him up
I dont know if he can explain you everything in the imperial measurement system, since austria also use the metric system.
If there are any language issues,hit me up, I'll translate your questions or his answers.