Hello, i'm trying to linearize in a MED9.1 a new map sensor 4 bar , just to have correct reading of actual pressure.

The sensor is this one :
3K906051
0281006059

First question is what are the mbar and voltage range of this 4bar sensor?

S4 wiki type 2 sensor:
0,5v ->   500mbar
4,5v -> 4000mbar

Other forum:
0,215v ->   200mbar
4,461v -> 4000mbar

Second thing, the relative maps are:
DSVDGRAD -> MAP scaling
DSVDOFS -> offset
UDSVDMN -> min voltage lower threshold
UDSVDMX -> max voltage upper threshold

Searching in the FR i've found the formula and tried to calculate the new scaling and offset but the value is over the max value permitted in ecu.

Anyone of you have installed and set a 4bar map sensor in med9.1?

Yes similar value by used 200-4000mbar settings...

DSVDGRAD of 894.960
DSVOFS of 7.584

In ecu there are 894,9688 and 7,5781

Which value have you used?

Is it better also to modify the 2 threshold?

Yes.. it seems work well 

Yes...as i said you before

Is Med9.1.2 capable of log more than 1,5bar of boost? I mean is this a internal limit or just a vcds limitation?
Or in other words is it able to log more than 1,5bar of boost with a better logger without 5120hack?

You don`t remember correctly.

VCDS is not limiting anything.