Injecting prior to turbo comp' impellers

[JohnA]

I see that the AFR at high revs hovers around 11:1

Have you tried to go leaner? I got most of the gains when being leaner than 12:1, all other factors being the same.

Also is it running race fuel? If so, the gains from these four nozzles might be more modest, especially if the FMIC is really good.

What sort of charge temps does it register after a few seconds at full boost?