Correct me if I'm wrong, but isn't the Factory HP Tune just that...the factory settings? All it does is give you the Ford settings, then you can go in and tinker with things as you wish. Then there's the "Diablo Performance Tune" where they conservitively "kick it up a notch" in the timing and fuel areas, giving you a higher baseline to tinker around with. Personally, I would use it for gear ratios, tire diameters and things like that, but if you wanna really dig deep into the engine settings then get it dyno-tuned.
the diablo tune is a more aggressive tune, the factory tune is for when you just want to swap the gear ratio and stuff like that without needing to run 91 or 93 octane
If you get a custom tune please do this. First run maxed timing in both ranges, as suggested above. When you get to the tuner, get a baseline graph of HP and A/F first. Then let him put in his tune and see what happens.
I paid $200 for a dyno tune and my SOTP meter tells me it was better prior to the tune. Maybe it's me, mabye it was too lean. Either way, I'll never know because he didnt' do a baseline run.
So make sure your money gets you something instead of just a dyno run, which would have only cost about $75 without the tune.
OK, so if I max out the timing across the board, does me living up 5280ft above sea level affect anything? Do I have a greater risk of detonation (pinging) being up here or do I have less to worry about?