What is the rating for the std Q4 map sensor, is it a 2.5 bar sensor?

If I fit a 1.7 bar programmed chip, do I need a 3 bar map sensor to make this work? I assume there are only a 2.5 bar and 3 bar map sensors available.

If the sensor only read to 1.5 bar(2.5 bar absolute) how can the ECU adjust timing and fuel above 1.5 bar boost.

The higher range is important to me. We had before that an engine's piggyback chip was adjusted on the dyno to 7000 rpm. In real life the Alfas std limiter allowed 7200 rpm and probably a little more on overrun. On a trackday the engine was ruined as above 7000 rpm the chip was not programmed at all and gave no fuel and made the timing too fast. The engine was running to lean every time it reached the redline. Since then I make sure that there are figures in programes at levels above my parameters.

This is even worse for boost levels. If something go wrong, and they sometimes do. If the boost goes higher than planned, the program must give the maximum amount fuel the injector can give, and pull the timing back aggressively and so save the engine.