[Richard L]

Do you have the same car, a 335i? I believe he has a solenoid valve as well as a checkvalve. The water line is triggered by boost (post throttle). Not sure he if has the same arrangement on the air line.

If his car does not have MAP in between, it may not have mattered. I think the 335i is a speed-density fueling system.

Reducing the water pressure relative to the air pressure can only improve the atomisation.

In any case. the setup should be bench tested before installation, baseline data helps to trouble shoot should if things are not going according to plan, as happened in this case.

He tests were done on a ~45F environment. Water/methanol droplet will condense when it passes through the intercooler. I expect the cylinders would receive varied amount of water/methanol. The DME was unable to trimmer fuel flow to each cylinder as there are only two lambda sensors, one for each bank of three. This could be the reason why the reason was not good.

I think one should only injection just enough to cool the turbo. He is injection around 650-700cc/min.