I managed to get this graph together.
Specs:
AUDI 2003 A4 1.8TQM: Revo/GTRS Eliminator turbo (GT28RS), Eurocode FMIC, Neuspeed Extreme TIP, 3" custom turbo-back exhaust.
Top graph Blue line is air flow (grams per second) and pink line boost in PSI multiplied by x10 for better appearance.
We can see that boost stabilizes at 14PSI @3500RPM. This is where maximum torque range starts. So if w would have WI on this car we would want to start injection at about 3400RPM. At 3400RPM we flow 110grams of air. At this point WI will start injecting @ 40PSI rate. As RPM go up air flow increases. At about 6000RPM our pump with PWM controller will be producing 160PSI and getting maxed out (220g/s air and 160PSI water which would correspond to twice as much air ? twice as much water).
Conclusion: With the given pump range of 40-160PSI and given AUDI engine volumetric efficiency, we can properly control water delivery only till about 6000RPM after which we max out delivery pump. After 6000RPM water delivery will start to ?lean out?
I would appreciate some comments / criticism.