Vacuum Gauge in tuner pro

Avinitlarge · Post by **Avinitlarge** » Tue Dec 30, 2014 8:09 am

I am trying to add a vacuum gauge (in-Hg) in the my adx, Im not too sure on the formula, could some help me out please?
I am using a MPX5700AP pressure sensor. Ive got a boost and MAP gauge working fine.

Boost gauge (PSI) formula ((((X/255) - 0.04)/0.0012858)*0.145) - 14.530
MAP gauge formula (((X/255) - 0.04)/0.0012858)

I think its (((((X/255) - 0.04)/0.0012858)*0.145) - 14.530)*-2.036025
Is that correct?

thanks

FXST01 · Post by **FXST01** » Thu Jan 22, 2015 2:30 am

Do you need to convert from kPa to PSI to inHg?

Avinitlarge · Post by **Avinitlarge** » Thu Jan 22, 2015 2:38 am

No, I don't have (I don't think) to but its the only way I knew how to do it.

FXST01 · Post by **FXST01** » Thu Jan 22, 2015 8:21 pm

I have been trying to figure out the same thing. My answer from another website and user VL400:

You can link directly to other items when configuring the ADX which makes the equations simpler and its worth using the baro item to get a true vacuum reading. Baro (or barometric pressure) is the MAP sensor reading at key on and engine off, its also updated during running under certain conditions.

Add a new item and the equation can be (X - Y) * 0.2952999 to display inches of mercury
X = linked to Baro
Y = linked to MAP

kPa to inHg is 0.2952999.