Raising boost is not the solution. You have a problem that needs to be fixed. Raising the boost to hide the problem will cause more problems in the long run. Chances are greatest that you have an air leak. High boost often creates or exacerbates them. The intercooler end tanks, the hoses, the compressor by pass valve, the idle air valve are all suspects. Another possibility is failed plug wires or cap/rotor that cause the spark to blow out. Another possibility is the fuel pressure regulator or injectors. The air leak is the usual suspect. You are far from the first to experience this, particularly on a 15 year old motor. On my car it was the idle air valve hoses. There was a crack inside the curve on one that could not be seen without removing the hose and that opened up only under higher boost.

Philip Bradley