WHAT AM I LOOKING FOR ON MY A/F RATIO

[THE ICE MAN]

I want to make sure i am going to be doing this right.
I am installing on a 1300cc engine with 10.5 to1 compression
and will be running 6 and 9 lbs of boost on high.
My question is do i tune it to 12.5 to1 without the water injection
then put water on, or do I tune it to 12.5 to1 with water inj.
If I tune it to 12.5 to1 without water inj. what will I see on my AFR when I turn the water inj. on?
I have a .5mm jet.
I will be running 50/50 pump and race gas at 105.5 octane
Thanks alot guys.