Ambient temperature

[Charged Performance]

This may seem at first to appear to be the proper response but more diagnosis is really necessary.

Besides temperature is there anything else that could be different? Eliminate things like your timing having moved or a change in fuel blends, etc. If you have narrowed it down to the intake temp difference has surpassed your previous knock suppression then the increase in jet size may be the likely answer. You may or may not need to retune for the effect of the additional water mixture.