It's the one Adz had before he went all Bling Bling
We haven't done any testing yet as Slimreaper only found out that it was doing last night after driving it home from getting it fitted. Just wondered if there was a straight forward explanation for it due to the higher volume of air in the inlet system or summat.
The only other thing I can think of that's changed is the turbo inlet pipe is now very slightly (and I mean very slightly) pinched between the hot and cold pipe of the IC.