Boost
October 29th, 2013, 07:58 PM
I've been wondering about this for a while but have not had the chance to check the part #s on the sensors yet. I am assuming that all 3 vehicles I am working on have a GM 3 bar map sensor as the all run more than 15 psi boost from the factory (although they could possibly use a 2 bar "boost sensor" just for pressure?)
Perhaps I am logging / looking at the wrong PID - or doing something even more foolish. The E39A, E78, and E35B all seem to max out at 37.0 psi "Intake Manifold Absolute Pressure". I have been looking at this PID and subtracting about 14.6 to estimate boost pressure because I am at sea level.
I find it hard to believe that all 3 vehicles are topping out at around 22 psi, regardless of the tune I am running. At first I really thought the map sensor was maxing out, but then I realized if they were using a 2 bar it would max out at less than factory boost?
It is also possible that I am not understanding something about basic map sensor operation...
Perhaps I am logging / looking at the wrong PID - or doing something even more foolish. The E39A, E78, and E35B all seem to max out at 37.0 psi "Intake Manifold Absolute Pressure". I have been looking at this PID and subtracting about 14.6 to estimate boost pressure because I am at sea level.
I find it hard to believe that all 3 vehicles are topping out at around 22 psi, regardless of the tune I am running. At first I really thought the map sensor was maxing out, but then I realized if they were using a 2 bar it would max out at less than factory boost?
It is also possible that I am not understanding something about basic map sensor operation...