There is certainly something going on with my car, though I don't know what. Altitude would be a common denominator, but on the other hand, so are the high temperatures the car has to run at (plus the less effective cooling due to altitude).
I'll be datalogging the car to get a better idea what's really going on as soon as my wideband shows up for my Hydra. But keep in mind: I'm tuned on speed/density (MAP, no MAF) so altitude shouldn't really make much difference... absolute manifold pressure, air temp, and rpm... things that don't really change due to altitude. 22 psi (well 37 psi absolute) at X degrees is the same amount of air, regardless of the starting pressure on the uncompressed side of the turbo, know what I mean?
But, I'm a tuning n00b... I'm just teaching myself this crap. Mike Warfield, who tuned the car, has tuned race cars that have run at Miller Motorsports Park without issues, so I can't imagine the culprit is the tuning as much as it's the driver pushing the car too hard. Besides, Mike's seen what I do to cars, I get the feeling he's not pushing my car all that hard on the tune 'cause he knows I (unintentionally!
) beat on it.
Though, it would be nice if the problem was something obvious in the tune at altitude, 'cause that's easy to fix. If the issue is lateral G's, or oil starvation, or lack of cooling, or something similar that will require reengineering the car... that's when making the car reliable becomes really expensive.
And on a side note: I've never seen a Subaru with a dry sump. Hell, I don't think even the WRC cars use 'em... it's just not needed on a flat motor, since the pistons are already half in the oil. I can't imagine I'm seeing G loads so bad they can starve out the oil.