I have a highly modified vq35 in a Datsun 240z. I was driving it, the car was running well, after 20 minutes the oil pressure went down to 5psi at idle and 30psi under acceleration. Previously it was from 30psi to 60psi. I got it home, checked the oil level (it was ok, a little high but not excessively), drained the oil (it was still clean as it only had 100km use), dropped the oil pan (no bearing shards/metal), pulled off the oil pickup (it had a few chunks of what looked like fuzz but not enough to restrict flow), checked the port to the sensor and checked the sensor it’s self (was clean with no debris, sensor is new). Any thoughts on what could cause this oil pressure issue?

It is a 2004 vq35 with the following upgrades: 8:1 pistons, rods, crank, all high end bearings and studs/bolts, mishimoto oil cooler, Garrett 3582r turbo (oil return into the bottom of the lower half of the block), 1000cc injectors, custom intake and exhaust, speedhut gauges, etc. The car is far too loud to be able to hear any knock, fluttering, or chattering.