oil pressure with system 1 dry sump pump

just installed a new system 1 dry sump pump on my bae cast block hemi, its in an alcohol dragster. bae -5, psi etc, how much oil pressure should it have hot and cold at idle, im using 18 quarts of 25w70 oil with 1 quart of lucas oil stabiliser, fired the car and had 150-160psi cold once the engine had really warmed up it had 50-60psi at idle (idle is 2000rpm) as soon as i lift the rpm off idle it jumps up, at stage rpm(5800) it has 140 and 160 if i give it a bit of a rev, not sure if this is normal its just my old TFX billet dual pickup pump had abou 80 -100psi at idle hot, stage pressure was about 20 psi higher, i adjusted the screw up a bit didnt seem to make a huge amount of difference, crew was set .930" from the pump housing std and i screwed it in .100".
i take my oil pressure from the system 1 billet oil filter mount.
any help much appreciated