Boost gauge, indication too low

Hello, I have been using this great app for a long time. Recently I discovered that the boost indication is too low. Max shows 1.53 bar when the actual boost is max 1.67 bar. In which configuration can I change it?

My car: Renault Scenic 2 2.0dCi

Assuming OBD2 connection, the boost value comes directly from MAP sensor reading (if MAP sensor is available). If there is no MAP sensor, MAP value is attempted to calculate from MAF sensor reading. This may cause error in reading. You could adjust the vehicle VE in garage for this.

what else can I change to make it show more than 1.55? what constitutes a limitation for the indication?

Internally there is no limit for boost value, so only thing that can cause this is that vehicle is not sending any bigger values?

PyClip diagnostic shows a boost of up to 1.75bar. See PR041-PR035. 2.72-0.97=1.75bar. RealDash sees max of 1.55bar.

I would like to help but its very difficult remotely.

Boost is calculated from either MAP sensor, or MAF sensor readings. If your vehicle has a MAP sensor, its default PID is 010B. That value comes in as single byte, having value of 0-255 kPa. That could explain the capping of boost to 155 kPa.

Ultimately, I think you need to make a custom OBD2 XML file to better match your vehicle to read the custom PID with boost value with more precision.