turbo boost fluctuations, causes?

[coldtaco]

Driving today I noticed a fluctuation in boost pressure whenever I felt what feels like hitting a 20mph headwind for a second or two, this driving at 65mph. Seems to be happening more on a slight incline vs on flat ground. Like boost above 10psi. 12HT with a non stock turbo. Thoughts what to check?

 

[Nz Nath]

Does the 'headwind' effect dissappear if you back off the throttle slightly?

And what is the fluctuation? If it's a boost drop that's probably because fueling has dropped.

 

[coldtaco]

The effect doesn’t last long enough to be able to make any throttle changes in order to see if that makes any difference.