I may have misunderstood, but I thought has was asking for cylinder compression, not the overall compression ratio. I'm not 100% positive about this, but I believe with a DET, 140 psi across the board is normal.
140 is about right. I saw some combustion chamber PSI figures from a guy with an NX2000 with an SR20VET in it. Maybe you guys know who I'm talking about. Anyway, his numbers ran anywhere from 140 to 145.
Stock Sr20DET compression should be around 170psi (highest) and 130ish/140is as long as each cylinder is within 5% of each other and even so this is the result of a worn engine. Do you have individual cylinder figures? Would help better determine what happened. I bet #2 is the weaker of the bunch...could be wrong though.