Quick update for my "Hardpipe Fan Club"
Re-visited the Forge/Dbilas connection (it was chucked together in terrible weather previously) and made it nice and tight now. It was a bit loose for my liking. Also re-orientated the hardpipe slightly as I thought it was too close to engine block.
Turns out the connection must have been a bit too loose as I must have had an air leak. The whoosing noise is now gone (which is a bit of a shame as it sounded just like my old ITG Maxogen lol) as the seal is now definitely nice and tight and performance seems even better.
So, ITG filter in OEM box + Dbilas Hard Pipe + Forge Turbo inlet elbow = Definitely noticable, car pulls much harder.
Power increase - who knows, probably not much but the way the power is now delivered is definitely for the better.
Chuffed it all worked out