Thanks for the replys guys, Ive also had the coilpacks checked and apprently are fine which is leading me to the CAS, It Defiently increases the problem when i run higher boost, The revs drop but not to stalling point normally sits about 1000rpm, Random drops to 500 on idle. Im thinking the CAS is internally damaged..
Aftermarket parts are the following:
3" Turboback Trust exhaust.
Turbo smart boost controller.
Power FC.
Garret GT30 turbo.
Bigger injectors.
Front mount intercooler.
Spitfire coilpacks.
Nismo Diff.
The restricting defiently feels like fuel/spark. Altho ive been told by the dyno results what is happening is my injectors are all switching off for like a milisecond, So im thinking earth/wiring problem Or Crank angle sensor =/