PEH,

Maybe I was not clear. To increase the output of the turbo from 12 psi to 15 psi, by "dialing it up" as you say, you would simply adjust the wastegate.

I think we all understand that the wastegate is the only control that the turbo has.

If you are at an altitude of 6200 feet and you were to adjust the factory wastegate setting of 12 psi and raise it to 15 psi, the engine would then put out exactly the same power as it would at sea level. You will not damage your engine. Now, if you return to sea level, and you do not readjust the wastegate back to 12 psi, then you can do some damage.

I cautioned the need for a boost gauge and/or an EGT gauge in a previous post.