altitude effects at Ofest

[Bob Sutterfield <Bob@xxxxxx>]

Oktoberfest attendees will want to adjust their expectations to the
conditions at the sites.  This afternoon at Second Creek, cars were making
only 84.3% of their rated horsepower.  (You get used to it but you don't
have to like it.)

Up at Keystone in July, 9300 feet and say 70 F, you'll see around 67% of
your book sea level horsepower during the autocross.  When the TSD rallye
takes you over a 12000 foot pass at 60 F, you're down to 62%.  Plan
accordingly!  Your lungs will be at a similar deficit, so you might want to
go easy mountain biking around the lodge.

Other effects to bear in mind:  With less atmosphere above you, the sunlight
is filtered less, so you'll be more prone to sunburn.  In the arid West,
you'll get dehydrated before you sweat.  With fewer air molecules flowing
past the rotors and calipers to carry away the BTUs, you'll see higher brake
temperatures.  Fresh high-temp fluid and pads are even more beneficial than
at sea level.

Get your dewpoint, temperature, and barometric pressure from
http://www.wunderground.com  For altitude, if you don't have a nav device
like http://www.rmcbmwcca.org/ice_gps.jpg you might check
http://www.airnav.com/airports  Then go to
http://rshelq.home.sprynet.com/calc_hp_dp.htm and enter the current
conditions at your location.
- --
Bob Sutterfield
'87 E30 325iS http://bmwe30.net #1129
'88 E28 535iS http://m535i.org   #154
BMWCCA #169277 Rocky Mountain Chapter

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