Boost/calculated Values not working right

I have a Manifold Pressure gauge already on my realdash app. it’s setup so 100kpa is athmospheric. so at idle i’m at 30kpa and 14.7psi is 200kpa

i also have a boost gauge for which i use calculated values/PSI under input source.

the gauge always reads around 15 and doesn’t climb or drop into - when my Map gauge reads vacuum.

What am i missing?

Check if the range setting is limiting the boost gauge values. Note that boost gauge will show 0 at atmospheric and negative under vacuum. If gauge range min is set to 0, it never shows the negative values.

Min and Max on the boost gauge is -14.504/30

Min and Max on the Manifold Absolute Pressure gauge is 0 and 400

I ran a test tonight. When I put the dash in simulation mode the boost gauge acts as it should

-14 at 0kpa

0 at 100kpa

14 at 200kpa

and so on

but when i plug it into the car the boost gauge reads -14.3 at 101kpa with the engine off

it’s as if the boost gauge suddenly uses gauge pressure instead of absolute. not sure what else I can check

Ok, I will run some tests too.

I changed the min value to -50 just to see and discovered that the gauge reads 30psi off

so at 100kpa it reads -30

seems like the math is wrong for me anyway. See if you can confirm. i played with gauge math but had no effect i assume because gauge math only works on source values