rnf2 wrote:
On Sat, 13 Mar 2004 07:57:39 GMT, Guy Alcala
wrote:

WaltBJ wrote:

More trivia on flight and oxygen:

snip

As for the Rocky Mountains, when we get flatlanders up here for a
visit and take them for a drive up over Trail Ridge road - peak
altitude about 12,200, they usually doze off because they won't
breathe (pant) enough.

(Almost totally OT) Ah, Trail Ridge road. When my '88 Subaru GL
Turbo 4WD Wagon was almost brand new, I took four people and all our
gear for a week over Trail Ridge (we'd driven from California, but
spent a night and half day in Great Basin Nat. Park, including
sleeping at 10,000 feet). The Subaru only had 115 hp and had a curb
weight of about 3,000 lb., and virtually everyone had a better
power/weight ratio and was faster than I was -- at sea level. So
there we were, climbing up the west side on a hot, muggy summer day
(it was in the high '80s or low '90s, I forget which, when we passed
through Granby @ 8,500 feet), and all of a sudden I found I was just
about the most powerful car on the road, as I passed what were far
more powerful cars (at sea level) while driving uphill at ca. 10,000
ft. I could drive as fast as I wanted to (max. 40-50 or so) uphill
on the fairly open two-lane road, with 1-2,000 foot dropoffs on the
side and usually no guardrails on the turns. Coming back over from
east to west was the same.

I never did find out what the critical altitude on the turbo was, but
judging by its performance on Trail Ridge that day it must have been
well over 14,000 feet (allowing for density altitude). Couldn't
have a more clear illustration of a turbo's thin air performance
advantage than that. I later took the car up to 13,200 feet in the
White Mountains one September with two people and gear, and I don't
remember any altitude problems there either, at least for the car
(it was graded gravel and dirt, so I wasn't driving very fast in any
case). Both of _us_ had AMS from ascending too fast from sea level,
even though we'd slept at 9,000 feet the night before.

My Subaru Forester (some SOB stole my old Subie in its fifteenth
year, or I'd still be happily driving it) doesn't have a turbo (they
only came out with the XT turbo model in June or so of last year,
and I had to buy a car that January). It's got about 165 hp and
more torque, so my old turbo would come up short up to about 8,000
feet or so, but have more power above that. Living in the SF Bay
Area at sea level and driving up to the Sierra it hasn't been a
problem so far, but I have yet to carry that much of a load that
high, that hot. The highest paved road in California goes over
Tioga Pass (9,941 ft.) in Yosemite, and it handled that fine with
two people and backpacking gear last August, so I probably don't
need a turbo here, and I'm happy not to have to worry about the
turbo blowing up or suffering other expensive problems (not that I
had any, but I changed my oil every 3,000 miles and let it idle down
properly after hard driving). But if I was living in Colorado up
against the Front Range and/or commuting across it, I'd sure want
one. I've read that Subaru developed the Turbo Forester XT
precisely because the normally-aspirated model was left gasping for
breath commuting through the Eisenhower tunnel (@11,000 feet). As
Homer Simpson might say, "210 hp all the way up, M'mm."

Guy


I wonder what my Isuzu Bighorn (Trooper to you 'Mericans) 2.8 diesel
turbo would be like there But for those that live high... aren't
there any factory supercharged cars to use? Like the Australian 3.8l
V6 SS Commodore? The Merlin and Griffin engines on the Spitfires were
supercharged, and they certainly went high enough

Could always buy a Jaguar, they certainly do a supercharged version.

--
James...
www.jameshart.co.uk