Pikes Peak Highway

What happens to a normal car at 14000 feet?

http://en.wikipedia.org/wiki/Pikes_Peak_Highway

Maybe it would be better to drive this in a rental.


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On 12/21/12 10:30 PM, Tom Del Rosso wrote:
> What happens to a normal car at 14000 feet?
>
> http://en.wikipedia.org/wiki/Pikes_Peak_Highway
>
> Maybe it would be better to drive this in a rental.
>
>

Cars do lose power. Going up is not too bad. Controlling your speed
coming down can be harder for most "flatlanders".

Check out the Mt Evans road. It is slightly higher than Pike's.

http://en.wikipedia.org/wiki/Mount_Evans_Scenic_Byway

Retired wrote:
> On 12/21/12 10:30 PM, Tom Del Rosso wrote:
> > What happens to a normal car at 14000 feet?
> >
> > http://en.wikipedia.org/wiki/Pikes_Peak_Highway
> >
> > Maybe it would be better to drive this in a rental.
> >
> >
>
> Cars do lose power. Going up is not too bad. Controlling your speed
> coming down can be harder for most "flatlanders".
>
> Check out the Mt Evans road. It is slightly higher than Pike's.
>
> http://en.wikipedia.org/wiki/Mount_Evans_Scenic_Byway

Do you have to stop periodically to let air out of the tires?

People would have trouble breathing. Does the O2 sensor compensate to an
extent?


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On 12/22/12 10:25 AM, Tom Del Rosso wrote:
> Retired wrote:
>> On 12/21/12 10:30 PM, Tom Del Rosso wrote:
>>> What happens to a normal car at 14000 feet?
>>>
>>> http://en.wikipedia.org/wiki/Pikes_Peak_Highway
>>>
>>> Maybe it would be better to drive this in a rental.
>>>
>>>
>>
>> Cars do lose power. Going up is not too bad. Controlling your speed
>> coming down can be harder for most "flatlanders".
>>
>> Check out the Mt Evans road. It is slightly higher than Pike's.
>>
>> http://en.wikipedia.org/wiki/Mount_Evans_Scenic_Byway
>
> Do you have to stop periodically to let air out of the tires?

No, it's not that much of a change
>
> People would have trouble breathing.

Most people have no problem, but do notice a slight "shortness of
breath". There is a situation called "altitude sickness" which is
normally only a problem if, say you arrive at Denver airport, and go
straight to high altitude without some time to adjust.

see http://en.wikipedia.org/wiki/Altitude_sickness


> Does the O2 sensor compensate to an
> extent?

As part of a car's ECM system, they do contribute, along with others
like the "knock" sensor, to adjust the fuel and spark as needed. In
general, fuel injected cars do much better than older carburetor
versions. I once drove a 1973 Plymouth w/318 V-8 (in 1975) up Pike's,
had pedal to the floor, doing 10 MPH !!

On 12/22/2012 07:25 AM, Tom Del Rosso wrote:
> Retired wrote:
>> On 12/21/12 10:30 PM, Tom Del Rosso wrote:
>>> What happens to a normal car at 14000 feet?
>>>
>>> http://en.wikipedia.org/wiki/Pikes_Peak_Highway
>>>
>>> Maybe it would be better to drive this in a rental.
>>>
>>>
>>
>> Cars do lose power. Going up is not too bad. Controlling your speed
>> coming down can be harder for most "flatlanders".
>>
>> Check out the Mt Evans road. It is slightly higher than Pike's.
>>
>> http://en.wikipedia.org/wiki/Mount_Evans_Scenic_Byway
>
> Do you have to stop periodically to let air out of the tires?
>
> People would have trouble breathing. Does the O2 sensor compensate to an
> extent?

most modern injector systems have an air pressure sensor for atmosphere
as well as the intake manifold. that is the primary input for
compensation, and the oxygen sensor will fine-tune from there.


--
fact check required

On Friday, December 21, 2012 8:30:23 PM UTC-7, Tom Del Rosso wrote:
> What happens to a normal car at 14000 feet?
>
>
>
> http://en.wikipedia.org/wiki/Pikes_Peak_Highway
>
>
>
> Maybe it would be better to drive this in a rental.
>
>
>
>
>
> --
>
>
>
> Reply in group, but if emailing add one more
>
> zero, and remove the last word.

I have driven both Mt Evans and Pikes Peak recently (last couple years) and my vehicle (2000 silverado z71) had no issues. I didn't let air out of the tires either. I have heard, probably on this ng, you can lose up to 3% of your total hp for every 1000' of elevation. No idea if that's true or not and/or limited to naturally aspirated cars only. My truck would burn rubber on asphalt at sea level and I couldn't break traction in the dirt at 14000'. So if that logic is correct, my truck has 285hp stock and at 14000' would lose 42% of it's hp leaving me with 165.3hp...

Tom Del Rosso > wrote:
>What happens to a normal car at 14000 feet?
>
>http://en.wikipedia.org/wiki/Pikes_Peak_Highway

What happens is people pull over to the side to look at the view and make out.

>Maybe it would be better to drive this in a rental.

I did it in a rental, and it wasn't bad, the road is actually very well
maintained. Modern cars with feedback control systems will run fine. Old
cars with carbs will run rich and lose power somewhat. People who lived in
Denver used to use reduced size jets for better performance up there. But
feedback control and injection has eliminated all that.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 12/26/2012 9:34 AM, Scott Dorsey wrote:

> I did it in a rental, and it wasn't bad, the road is actually very well
> maintained. Modern cars with feedback control systems will run fine. Old
> cars with carbs will run rich and lose power somewhat. People who lived in
> Denver used to use reduced size jets for better performance up there. But
> feedback control and injection has eliminated all that.

All normally aspirated cars, whether they use carburetors or fuel
injection, will lose power and it has nothing to do with whether
or not they are keeping the fuel/air mixture correct. Turbocharged
and supercharged cars have the advantage.

Mark Olson > wrote:
>On 12/26/2012 9:34 AM, Scott Dorsey wrote:
>
>> I did it in a rental, and it wasn't bad, the road is actually very well
>> maintained. Modern cars with feedback control systems will run fine. Old
>> cars with carbs will run rich and lose power somewhat. People who lived in
>> Denver used to use reduced size jets for better performance up there. But
>> feedback control and injection has eliminated all that.
>
>All normally aspirated cars, whether they use carburetors or fuel
>injection, will lose power and it has nothing to do with whether
>or not they are keeping the fuel/air mixture correct. Turbocharged
>and supercharged cars have the advantage.

Well, we have two different kinds of loss here. Yes, there will be some
loss just due to the lower air pressure. If you go up to 10,000 feet,
the air pressure drops to about 20 inches of mercury instead of 30 at
sea level, so it's like having a throttle that only opens 2/3 of the way
there.

This isn't an enormous loss for most cars, since you wouldn't normally
be going anywhere near full throttle driving up a dirt road on a mountain
anyway.

The second kind of loss is the loss due to the rich mixture, and that is
more significant when you're driving a car subject to that.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Mark Olson > wrote:
> On 12/26/2012 9:34 AM, Scott Dorsey wrote:
>
>> I did it in a rental, and it wasn't bad, the road is actually very well
>> maintained. Modern cars with feedback control systems will run fine. Old
>> cars with carbs will run rich and lose power somewhat. People who lived in
>> Denver used to use reduced size jets for better performance up there. But
>> feedback control and injection has eliminated all that.
>
> All normally aspirated cars, whether they use carburetors or fuel
> injection, will lose power and it has nothing to do with whether
> or not they are keeping the fuel/air mixture correct. Turbocharged
> and supercharged cars have the advantage.

The time I drove a 64 mustang to the grand canyon, it felt like I had half
the power.
That's about 7000 ft. My 77 datsun ran just ok in the high desert of 2-3k
ft. It had an altitude switch, no feedback injection. I think the set point
was 3k ft. For the switch.

Greg