I have a rebuilt engine with nismo high capacity oil pump, AAM oil pan spacer with upgraded oil lines from AAM to the turbos (Greddy Setup) and my oil cooler is from stillen.

the oil pressure showing around 90 PSI on my defi gauge at idle is that normal?

what is the best oil pressure while the car is idling, and the best oil pressure when i am giving full throttle?

 

This isn't "best" it's just what I observe on my '04 with stock oil pump.

cold idle: ~90
warm idle: ~20
warm driving: ~50-90 depending on rpm.

 

All I know is that if its around 8-10psi at warm idle you are most definately F***ed

 

I'm sorry you and your mechanics learned that the expensive way Cass...hopefully things work out for you. Don't give up man.

 

Mine is always at 20psi on warm idle...

 

Warm idle 25-30

Cold idle 90-100 drops to 60 quick

Regular Driving 60-90

 

90 only on cold start up

 

I have a Nismo oil pump also, we plugged the piston oil squirters on the built motor & a GTM external oil cooler.
Cold idle pegs gauge @ 120psi
Hot idle 40psi
Cruising @ 3000 rpms 65