This is a huge debate for us kids at altitude. The biggest problem with the SAE correction formula is that it does properly calculate things for a wastegate controlled turbo car. Now, its really close, but not 100% because the manifold pressure is a constant that is controlled by the wastegate and only the ambient air is affected by altitude.
Also, at altitude the SAE corrected numbers are significantly higher than the actual numbers because of the lower air pressure (about 12.5psi ambient up here, vs 14.5ish of sea level)
For instance, a friend of mine with a Vortech centri on his '02 Mustang GT made 398whp-ish SAEcorrected, but it was only 336-ish actual. He just moved to GA where its damn near sea level and he went and made 401whp actual on the exact same setup and 397 SAE corrected on that same run, since the DA was equivalent to just a hair *below* sea level that day. So the SAE correction formula in my experience is about spot-on for anything *not* wastegate controlled, so long as the car has the equipment to safely make that power at sea level - another friend in a '98 Cobra with a procharger made 460whp SAE here in ABQ but was still on 24lb injectors, so to make his 400-ish actual he was pretty much maxed on his injectors despite the altitude, so the corrected number was bogus because his car would have run out of fuel trying to make that power at sea level.
Hope that helps.
