i have one of these on my aum and its ok but try screwing the blanking plug on instead of the flute and see if theres any difference,
mine was alot more responsive
Does that not just make it a fully recirc valve?
Why not just buy a 007p?
i only paid 80 quid for it and i have best of both worlds
was using it with the flute at first , then changed it to see the difference
for me it made a good noticeable difference so kept the blanking plug on