If anybody isn't aware:
Remove N75 valve, turn screw in end 1/2 turn anti-clockwise (it's hard to shift) and refit
I had a spare one so thouht I would try it out. Definately seems to make the boost come in with more of a punch and it also seems to hold the boost further along the rev range before tailing off.
Wondering if anybody else has done it and how they've found the effects?