[MeanMike]

Which Firmware version do you have? 2.01 or 2.05

I'm not an xfi expert, but I have looked at this a little. I don't have a copy of the 2.01 software so I'm not sure if it has any barometric pressure (altitude) compensation.

If you have or upgrade to the latest version 2.05, you have an option to run in load indexed speed density mode. You have to have an extra 1 bar map hooked to one of the aux inputs and reading barometric pressure. Then it compares that barometermetric pressure and manifold pressure and compensates. If you don't add the baro pressure input, it looks at the main map when the engine isn't running and still compensates.

If you have 2.01 and want to upgrade to 2.05, you'll have to populate a few new tables, but not necessarily a whole new tune. If you have 2.05 and just need to add the barometric sensor it shouldn't take a retune.