Knock tendency depending on Water Injection and Ignition

[mrx79]

Hi,

i have a question, and i hope to get some answers from ppl who have real live experience with that topic.
imagine the following scenario:

you tune an FI Engine to 20psi of boost with a given CR of X:1 and Y octane fuel to almost MBTT without water injection
let's say, you are away 2degree from detonation borderline (theoreticaly)

now you switch on water injection to get some additonal safety margin and i think you will losse some power if everything (mixture/ignition/boost) stays the same.

now you have to advance the igntion by 10deg to regain the before lost power.

how far away do you think you are from detonation now with water injection and more ignition advance?
is the safety margin got bigger/smaller/stayed the same and why?!?

hope to get some answers ;-)
Best regards and thanks in advance.