engine resource and power mods

[Andrei Kogan <abk@phy.duke.edu>]

This one got to be an FAQ, but I haven't seen
anything on the matter for the last several months, so here it goes:

When you chip up the car, and get this blazing *ss boost increase, what
does it do to your engine? I mean, is there any statistics available on the
expected lifetime of the engine/turbo after the mod? Is this a luxury for
people who can afford loosing the engine before its scheduled death due to
"natural causes" (although I am not quite sure what those are, one would
think the engine , if not defective, will run forever with regular
maintenance) or is it something that everyone can and should do? If so, how
come Audi didn't just put 2bar turbos in their cars? Or is the logic
roughly : "look, the stock engines last a long time after the rest of the
car falls apart (or looses "value", whatever that is) therefore, we can run
them harder?

Comments, please. 

Andrei