How much boost before the engine blows?

I found my 89 impulse in a junkyard some where in WI. I paid $200.00 for it knowing it had a blown head gasket. Well now that i have had it running i'm starting to do some mods. So far i have removed the cat and installed a BOV. I noticed after i installed the BOV there was not the correct amount of boost to make the BOV work. So i was looking at the turbo and noticed that there was a wire that ran from the wast gate to a elctric motor. I have never seen this before on a car with a turbo. I had no idea what it did until i disconected the motor. I found that it restricted the amount of boost supplied to the engine. So now i need to know how much boost i can run with out blowing my engine. I don't have a boost gauge yet but soon will. I will post what kind of boost my car runs once i install the boost gauge.

Let me get this straight, you installed a new BOV, it doesn't work properly because you got one for higher boost pressure, so your answer is to disconnect the wastegate for more boost? I can only say that I hope you don't overboost that thing at freeway speeds, cause it'll make a huge mess if you do, and the car will go straight back to the junkyard.

Thank you for your reply but i don't think you know what i was trying to say. I was trying to get info on my engine so my engine would not blow. That is why I am installing a boost gauge. Also I'm not that stupid to just tear out my wastegate. What I was trying to ask was if any one else has disconected their wastegate restrictor. If you don't know what i'm talking about it is a motor on the driver side that pulls on the wastegate when their is unwanted boost. This wastegate restictor saves gas but takes power away. So maybe this will give a little more info on what i'm taking about. Thank you

thats a dedicated turbo control unit.It controls the wastegate.The stock internals can hold up to 20psi.Not for long period of times though without proper cooling.The 4zc1 and 4zd1 are the toughest 4cyc isuzu ever made.