Barometric Corrections

Good day I'm curious if there is a general rule about barometric corrections or you go by trial and error? From my understanding I should go leaner as the altitude increases in order to avoid going very rich correct?

Yes, you can see the variation here - https://www.sablesys.com/support/technical-library/barometric-pressure-vs-altitude-table/

In practice, though, if you're using manifold pressure for the engine management it will be accounted for there.

If you are using throttle bodies, or similar, you can usually use an auxiliary input for ambient pressure, I've done this before.

Actually I'm running ITBs plus its a daily and that's the main reason I'm asking!

Ah, I did it because I was going from normal sea level use to passes of over 1000 metres, a drop of 13% in density. You, and others, may live in areas where several thousand metre variations may be normal, and it will make a difference.

What ECU are you using, it should have an input for pressure, if not, you may just have to tune for where you normally reside and use the vehicle? Mine used a rather older setup, and I can't recall if I had to input a correction, but I expect modern ECUs to automatically correct - it not, use the chart I posted earlier.

Anyone else?

My current ECU doesn't implement a barometric correction and as you said I have lot's of altitude variations (800 to sea level and back + some extras). I'm building a DIY ECU (Speeduino) that has the ability to have a baro sensor and some other stuff I would like my 30 year old Honda ECU to have. Currently I battling to clear the VR sensor signals. Honda did an elaborate job to have a clean signal in the ECU and probably I would try to replicate there job as I'm opting for a PNP solution for redundancy.