hi mate.
Sorry should have said, im on a stock ECU, and see the normal 6/7/8 psi.
Check your N75 valve mate, i had to change mine, and apparently the k03s was made with the F variation, i had a C. GOt rid of surging on mine and low boost problems.
All i can think of, unless you have a leak somewhere, or revo has been reset to low boost settings?