I ran mine at 40psi for almost two year and was fine until I bump my timing up and put injectors in one time of 60 65 and it and my stock head gasket was done the turbo still worked but if got on it past 20 psi it would lock and squeal and you would have to let of pedal and re step down and watch psi but you the common rule is 35 max.
I ran mine for a long time at 45, the turbo still lives today (an easy life) on a first gen.. But like what was said before, anything after 32-35 and it won't benefit you any..
47-51 psi with the 60mm upgrade wheel, edge 98.5 24v boost elbow and a 16cm. wastegated ex. housing. thats 100#fuel plate, mack plug, and 5x.016 injs. still goin since oct. 07:badidea: