AFR Tuning After Adding WI

[Mazdabater]

My engine is a FD 13B-REW with all the supporting mods for power and reliability. Initial safe tune without any WI was 11.1 AFR at 16 psi boost which has been run for a few years without mishap.

For safety I added 350 cc / minute water only injection back in late 2010. With this, AFRs richen up to about 10.9 and I lose a little power.

I want to now tune to gain that power back or increase power a little. What is a good way to do this? Should I reduce fuel enough to lean out the AFR back to where it was before adding water, go a little leaner?

IN THEORY: If I want to maximise power, would I:
(1) calulate and adjust fuel by: (11.1/12.2) * fuel which would give an AFR of 12.2.
(2) add enough water so that with the above fuel my new measured AFRS would be again 11.1?

[cewrx7r1]

My engine is a FD 13B-REW with all the supporting mods for power and reliability. Initial safe tune without any WI was 11.1 AFR at 16 psi boost which has been run for a few years without mishap.

For safety I added 350 cc / minute water only injection back in late 2010. With this, AFRs richen up to about 10.9 and I lose a little power.

I want to now tune to gain that power back or increase power a little. What is a good way to do this? Should I reduce fuel enough to lean out the AFR back to where it was before adding water, go a little leaner?

IN THEORY: If I want to maximise power, would I:
(1) calulate and adjust fuel by: (11.1/12.2) * fuel which would give an AFR of 12.2.
(2) add enough water so that with the above fuel my new measured AFRS would be again 11.1?