E85 "standard" ignition timing rule for NA engine

Hi,

I'm converting my car to E85.

I'm not a professional and I have no dyno.

I tuned the injection timing with an AFR gauge, it's OK now.

I would like to tune the ignition timing, is there any safe and/or common rule for WOT and partial ?

I found many post for Turbo engine but nothing relevant for NA.

I plan to rent a dyno but would like to start with a base map.

My ignition timing were tuned on dyno but for gasoline.

Here my current maps (Tuned) :

And stock:

I suggest starting with your gas tune, only altered to account for the change in fuel properties (in terms of fueling. I'd leave ignition timing and lambda targets alone. Dyno the car, observe the change in output based on the fuel alone. Then start making additional changes. It's a good learning lesson I believe is worth doing and only takes a few minutes to get a new baseline before further changes.