The reason for me asking is I believe I have a problem (that improves the cars feel)
Now and again 45% of the time I suddenly get a flutter noise with my BOV being very loud, the car also feels so much smoother and quicker.
My only explanation for this is a fault occurs in the VSV system or which ever controls the 2nd turbo's wastegate and rather than the wastgate being open at low revs its closed. So with both wastgates closed ALL unused boost is firing out the BOV coursing it to be louder and some going back into the turbo causing the flutter. If the 2nds turbo wastegate was open alot of unused boost can escape that way.
So by having both wastegates closes until it hits 1.2 bar when the boost controller opens them up I will get this great feeling and sound out of my Supra.