I have now a 4psi diference between front and rear tires and the noise is 70% out. Before it was making that noise @ 4000-2500rpms. Now is way less and only from 2500-2000rpms. I got a 6 puck disk exedy pp and 11pd flywheel on a jdm 6spd tranny.
Note if you put a 7psi difference or more your lsd will make a clikkk noise when making slow turns.