Nozzle sizing for 2d AND FLOW LIMITS

[s4orce]

Richard or who ever can answer this, I have a question. I currently have a system 2d with one accumulator running a DDS3 Gauge ( really cool BTW ) and currently running two ( 2 ) 6mm nozzels. this is installed on a 2001 audi B5 S4, running RS4 injectors at 5bar. I am not sure the flow rating of the rs4 injectors, they might be 42lb injectors at 4bar but not sure. Anyway, I am upgrading my system to run 3-4lbs more boost with 60lb Siemens Deka's at 4Bar. I would like to increase my nozzle size but not sure by how much or if it is possible with my current setup. I am mathematically challenged so your help is appreciated.

Which nozzle sizes should I upgrade to ? what's the correct water injection to fuel flow ratio ? 10% , 11% ?
If I move to larger injectors will my current setup support it ? If not, do I need another accumulator ? If I do, how does this get installed ?

Since I am switching from the RS4 injectors to the Siemens 60lb injectors how do I adjust the Aquamist to better map injector Pulse width based on this new fuel injector. I am not sure how the former installer wired it and now he's out of business and can't be reached. I know how the boost selonoid works and where it is located and how to adjust that, Now i need to know how I adjust the aquamist system to map better to this new injector. Is it done thru the DDS3 gauge, or what ?

Thanks in advance for your help..