So right now I have a Forge DV and boost gauge. Recently I've been noticing that at part/half throttle under decent load, up hill, etc. that I will get a quick boost spike to 15psi and then it will drop back to like 5lbs. or so. When I go full throttle it will maybe boost to 11 or 12psi then fall back to 9psi. Whats the deal here? Before I ever put the gauge in I could feel the car pull hard for a second and then go back to normal which I now can attribute to what I see on the boost gauge. What could be wrong here, is it the N75 going bad? I realize the full throttle spike and drop to 9psi is normal but my concern in the spike under part throttle.

Thanks

 

Its a turbo car, boost is dependent on TB angle and load. At part throttle and uphill like you said you can generate more boost than what the n75 is set for. Also need to take into account the turbo is very tiny. It doesnt hold boost well at all. This is why you seem to spike to 11psi or even 15psi and it will drop way down to about 5-6psi at ~6k. The turbine just cant keep up the airflow for 200bhp at 6500rpms.

Basically what im saying is everything is 100% normal