Interesting, cheers Dan. I am glad someone else has also pondered on this and looked into alternatives.
I am getting a Stage 2+ Revo flash tomorrow, so I will see if things improve. I did wonder if their tune is specifically matched to their own intake, but then again if it was, surely they would insist on using their own intake and not let you use Brand X? When I enquired with Revo HQ, they just said an intake was required......not theirs specifically. Anyway, I'm sure a Revo tune + Revo intake should work better.
MAF scaling is certainly an issue. I remember back in the day playing with VR6s and Vortech blowers. The OEM MAF hated it. That whirlpool effect I mentioned where the air flow is denser at the pipe perimeter compared to the middle - i.e. smack bang where the sensor reads from! People who'd binned the laminar corrector 'for improved flow' reasons suffered even more. The engine would barely idle. Modern MAFs have improved with directional characteristics to cancel out back flow from recirc valves, but mounting it so close to the turbo is still an issue, hence why they still use the air straightener. Not a problem if the MAF is mounted far way from the source of turbulence, like the TTS engine for example.......but for us EA113 boys, it needs careful consideration when moving away from stock.
Sounds like you've managed to pull it off. I would prefer a straight, uncalculated MAF reading in Litres per min instead of grams per second, since the engine volume is in litres and we know what the mechanical ingestion amount at idle should be. Then we can see if the aftermarket intake matches it exactly. Simply looking for ~3.5 g/s at idle isn't always a good indication it's accurate. I get the same readings at idle with the Revo as I do the Stock intake......but the stock intake idles a lot smoother and is more eager to get moving.
Anyway, tomorrow will be a good test!