Australia has 98 octane and considerably better access to E85 than the UK. Their temperatures aren't THAT hot either, can hit single figures in their cold seasons in some regions.
It comes down to a lot of bullsh*t. Remappers are like the media....fake news to garner more sales. 380hp from a K04 is laughable along with unfeasible in the laws of physics, but people still buy into it because they don't know any different.
BMEP and turbo flow are what they are, and yet people constantly believe the BS dyno figures over science
Dynos are incredibly easily to manipulate to give sales generating numbers, but it's always the same.....those who question the scene figures are heretics and naysayers.
310-330hp is about right for a tuned stock K04, and indeed 330hp is the figure VW motorsport themselves quote as a maximum safe limit for the CDL (S3) engine. Extracting an additional 50+hp from there, from thin air, just has to raise questions in your mind. Turbos can't suddenly muster up an additonal 30% more flow from nowhere, so if the numbers seem overly optimistic to you, they are. Trust your instincts. Why would a car manufacturer leave 100+hp tuning headroom in their engines when a smaller turbo and more conservative tune would suffice and save them money?
Look what measures Audi took to raise the AAX, BYP engine from 200hp to 265hp. Bigger turbo, bigger intercooler, bigger injectors, more HPFP lift, different cams, different mapping, stronger pistons, better piston rings, lower compression, thicker wrist pins, 4 bolt mains, harder cylinder head etc etc. All that for 'just' 65hp. If it was just as easy as running the K03 at a higher boost pressure, why didn't they just do that themselves and save themselves a f'ck ton of money? I'll tell you why....because they know how to build and tune an engine. Remappers only know how to wring an engine's neck and don't care about life span.
I've personally experimented with running a K04 flat out, and beyond, and the results are far from satisfactory. Yes you can get silly torque as a short term spike, but it doesn't and can't hold it, because it's a tiny little cotton reel turbo feeding a fairly restrictive and basic 2 litre engine. Let's get real.
Mate.....330 is all the K04 can deliver. Anything above that, especially on a rolling road, is utter bollocks.
And Kudos to the Ozzies for measuring power how it is, in KW @ the tyres. None of this marketing 'brake' horsepower flannel