The Curve you see, is Indeed boost, however it is not "Only" just boost that gives you this power increase\curve...
It is a mixture of fueling & boost. Then you can break down how the fueling is done, and in turn break down how boost is initiated using the requested fueling trims, tables and rpm. Making them all come together is where it satisfies both the driver and tuner...
Stock coolers on the 330d (e90) can only handle a set amount of volume, we have tested this and have found a max boost that the cooler can handle - its not much...
at 1.6 Bar boost, the correct Fuel trims and stock hardware - this is our Custom remap - which in turn becomes this customers stage 1 remap.
We have had similar power figures attained across the board from LCI 330d's - Kameels (Kamz) 330d is running on his Custom Stage 1 file for 1 year now with no issues. I have pushed my personal vehicle a little and still running with out any issues (I have Cooler, Downpipe & Exhaust)
Coming from 1.9TDi, i know these turbos very well

. We use 330d Turbos for our Big Turbo applications - and we boost them at 2.0Bar with no issues :cartel:
Back to this particular Dyno\Vehicle - the Turbo is still "well" below its threshold and well within its A/R spec for both Spooling and Final End Boost. :chef: