90% isn't maxed out! Nistune also allows to adjust TP Load Limit, i.e. boost cut. Could be your problem (along with needing bigger injectors).
So how does boost cut work? the boost solenoids were removed years ago,and the only feedback of boost to the ecu is the boost pressure sensor. Some of the un graphed runs show much higher duty cycles.
If your load exceeds a predetermined limit it will not allow the load to go higher. Load in this case is TP (theoretical pulsewidth), or how long it opens the injector for in a perfect world Read all of me
