RS2 Cam timing & components

[Jamo]

Dont' forget that your lining up the two cam marks inside as well

[twoqu]

Also that seems right. The half a tooth difference is down to the one less tooth on the cambelt. Just as the "extra" tooth on the ABY/AAN puts the pulley back to the correct alignment.
That also suggests the pulley has the same relationship between the keyway and the marking.
Without doubt being a limited run model, Audi were not going to tool up to make a batch of slightly diferent components. So they have modified or adapted what would have been stock ABY components to do the job.
I understand the principle of the water pump difference!

[twoqu]

So are we suggesting that its the cam sprocket on the exhaust that alters the timing of the inlet. That makes more sense.