...mainly in 2nd and 3rd gear when im waiting to overtake, revs about 4k with the pedal kept still, the boost guage showing about 0.5BAR, my blitz VTA valve will be constantly dumping until i accelarate or change gear, while doing this it also makes the engine hesitate and judder.

is this normal? do i need to adjust the bolt to tighten the spring?

 

My MY01 Forge one did exactly the same in exactly the same circumstances....I cured it....I took it off