Hey, one thing to keep in mind when you talk about HP and turbos...Turbos
do not suffer much from HP loss at altitude, so.    Anyone who's done much
driving above about 4500' above sea level knows that your Normally
Aspirated motor loses a lot of power up there.  So, 70-some HP that stays
there all the while, despite climbing up mountain passes...that will seem
pretty strong despite the low number..

I've not owned a turbo but I gather that they will take "boost" to the
same point no matter what the altitude because most are controlled by some
type of waste gate or pop-off valve system which measures the internal
pressure to a set level at altitude or sea level.

  The normally aspirated inline diesel at altitude?  Woefully underpowered
almost to the point of danger.  Even fully loaded 18-wheelers can get up a
grade better than a Diesel Westy full of stuff and people...The one time I
rode in one, we had 4 quite close calls (in just over 10 miles) from irate
California drivers executing very unsafe passes while we crawled up a
windy but not very steep grade.  Scary stuff...
  Don Hanson