WI on my Supra

[supraNA-T]

Hey guys.
I'm new to this forum and looking for some insight on Water/Meth injection.

My car is a 96 JDM Supra SZR NA-T.

I'm installing a AEM WI kit

Now i'm running 1.1bar as max because of my TThg..they say this is about max on 98ron fuel

How and how much would it be safe to turn up the boost on my NA-T Supra

I use a MapEcu2 for fuel and timing control.

Any input would be great
The grey one is mine, and the black is my bosses