I don't know where you're from, but the tuners should be familiar with, and be able to tune based on lambda values. If not, calmly explain to them what lambda is. Maybe point them to the wikipedia article. At the least, carry a calculator with you and tell them any A/F ratio they want, you can tell them what the lambda is. They can give you 14.7:1 and you'll divide 14.7 by 14.7 and tell them "1.0" lambda. They say 15.5:1 and you divide 15.5 by 14.7 and say "1.05". They say 12.2:1, you take 12.2 and divide by 14.7 and say "0.83". Do that a couple times and they'll get used to it very quickly. They should even start to prefer it.
As for your high VE numbers... I don't know how many times I've seen this. Someone hears that 12.2:1 is a safe ratio to run for a turbo car, so somewhere along the lines they add their own measure of safety into the mix, and call it 12.0:1. A couple more recommendations down the line of people adding their own margin of safety, and you get the idea that 11.0:1 is a good A/F ratio to run. It is not. 12.2:1 is safe. 12.0:1 is rock solid, stupidly safe. Even then us Americans get made fun of by the European tuner community for our "insanely pig rich" turbo tuning at 12.0:1 A/F. Even cliffb75's calibration guide on this forum recommends nothing richer than 12.9:1 calling anything richer "over fueling". This is what we're doing when we take the ratio down to 12.2:1. We over fuel, for safety. There's no reason to take this down to 11.0:1!
If you tune up to 12.0:1 at the very least (maybe 12.2:1) then you'll notice your VE values get much, much lower. The difference in your setup between 11.0:1 and 12.0:1 at 240 kPa is probably anywhere from 40 to 80 units. Your value of 218 now turns into 150 or so; something much more like what the rest of us running high boost have in that map area.
I know rob isn't the kind of guy to second guess someone's A/F ratios, but I am. You should give what I've said some consideration.
