how to log manifold vacuum (-120kpa-80kpa)??

[my_bd]

Could someone help me wrap my brain around how to log manifold vacuum in a histogram. I would like to log the Injector Offset vs Battery Voltage vs KPA VAC tables, however the histogram will not load due to unsupported or missing parameters.

My vehicle (04 Ion Redline) has the LSJ engine.
The factory tunes default to using a Vacuum-based injector offset table.
This table ranges from -120 kpa to 80 kpa, which happens to correlate with the Injector flow rate table.
I have tried adding all sorts of parameters to the pid table but cannot get the histogram to display the way I want it.

Out of curiousity I switched to the Map-based injector offset table and bam! the histogram loaded and displayed immediately.
But the Map based table is ranging from 20 kpa to 200kpa and so I can't figure out how it relates to the other tables in the tune since the range is skewed.

I would prefer to log using the vacuum-based offset table so that it correlates with the ifr table ranges.
-120kpa to 80kpa.

thanks!

[jimmyblue]

vacuum is BARO-MAP, you might have something different to
deal with if it's a turbo car but I think you could make a user
PID if there isn't one already for it. Or maybe BARO is what's
missing from your logs (it's usually not an interesting thing,
it never changes so nobody logs it).

[my_bd]

thanks, yeah after you mentioned Baro-Map a lightbulb went on and I realized that my existing custom boost pid (in psi) could hold the answer I've been looking for.
So I created another custom boost pid in kpa.
[PID.11.MET]-[PID.2340.MET]
on my car this gives me MAP kpa - Baro kpa (the reverse of what you suggested).
Using the resulting logged data I can now easily create the histogram ranging from -120kpa to 80kpa.