Every mainstream EFI system, including OEM's, run atmospheric correction factors.
My personal testing, and I'm sure Mark's personal testing as well, show when the atmospheric correction settings are turned off, you have to manually adjust the tune with elevation, for the exact same pressure and rpm bin. There is more effect on and engine fuel mixture from atmospheric pressure changes than just changes to the manifold vacuum(pressure).
Ray is wrong, he'll say I'm wrong, blah blah and blahs aka pissing match. OEM's spend millions of dollars on their tunes, and still use a correction factor, some how I don't think their "tune is off".
Last edited by TheSilverBuick; 09/20/14 04:04 PM.
