you can have a d16y8 running 200-220 whp on a really good tune (aka fuel management that can handle the amount of air the turbo brings to the motor..)
imagine having a turbo flow alot of air into the motor and not enough fuel... kaboom

there a car running say 5 psi with horrible or non existant tuning, would be less reliable than a 8-10 psi tuned motor...