Diagnosis of my lack of kick over 5000 rpm

[neckarsulm]

Update - my kick is definitely back since my mod a few weeks ago.
When it happens it feels like the extra air/more dense air that enters the engine is given more fuel by the ECU which feels like you have pressed the throttle a little bit further down - I guess this is what a turbo does hence why it feels similar to my B5 when it comes on boost, just 3000 rpm later!