Thats possible, however i'm pretty happy with the data i have managed to collect so far.

Just need to get some time to work on it, been busy with family stuff and work so havent got near it for a couple weeks. I did get some 5 lobe torx bits to remove the sensor from the TT MAF i bought (I bought a slightly different - larger - unit from ebay to my original ones, as it was a better fit for the factory intake pipe), as for some reason the housing is disgustingly dirty and needs a bath. Might also swap the sensor element for a spare one given the state of the whole thing.

Dragging this up from the depths...

In short, its working!

I'll need to upload the code to github or something.

In essance, the arduino reads the output from the Bosch MAF on one of its ADC inputs, uses that to lookup the correct value in a lookup table, and then sets the DAC output to the required voltage.

The Arduino's 5v regulator sends a 5v reference to the bosch MAF and to the DAC board. I've also incorporated a 9v DC DC converter on the input to the Arduino, just so its not having to deal with full alternator voltage (the included linear regulator has a max input of 15v).

Connected it up yesterday, and it works, drives great, if anything it feels a little more snappy on the throttle, lets hope it keeps working :)

Very good, well done!

Great job!
Sorry if I have missed it, but which VAG MAF did you use as a substitute and where do you find a calibration curve for them?
TIA
Steve

I have been following this with interest, and serious Kudos for getting it going!
Now......You seem to have come up with a somewhat universal translator, so can it be used to fit
a quality, but lower cost replacement for Bosch?
The genuine Bosch MAF is available, but big money!
Also there are so many fraudulent copies out there that getting a genuine one can be a challenge!
Cheers!