I traded one of my gauges in MegaTune for a boost gauge, that goes from 0 to 20psig. For some reason it shows about twice the boost I'm actually running. The mechnical boost gauge in the dash and the MAP gauge (when converted to psig) both say about 7psi but this one says 13 or 14.

Any ideas what's wrong with it? I don't really care as I have plenty of other ways to find out my boost, and plenty of other gauges to fill that spot with but I was just wondering about it.

 

is you configurator setup correctly for which MAP sensor you have? does the vac/boost gauge read correctly?

 

no baro right? did you put that normal atmospheric pressure was (whatever it is in bangor, me)? At sea level it's 101. MT calculates based on what your normal atmospheric pressure is. something like Absolute pressure - barometric pressure.

I know with an MS without baro correction it reads baro when you first turn on the car(ms) if there is a reset at any time while the car is running(ie burning a new msq) it reads the MAP as baro pressure and then calculates boost completely wrong based on that if the car was running at the time. Reason, you are in vacuum when car is running. Typically around 30kpa if at idle. So now it sees 100kpa as 70 over baro which is ~10psi.

Also check the baro sensor you have selected in config and in Basic Settings -> Costants page