• Hey Guest!
    British Car Forum has been supporting enthusiasts for over 25 years by providing a great place to share our love for British cars. You can support our efforts by upgrading your membership for less than the dues of most car clubs. There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Upgraded members don't see this banner, nor will you see the Google ads that appear on the site.)
Tips
Tips

General Tech High altitude adjustments

Share this page

R

RonR

Jedi Trainee
Country flag
Offline
Folks,

I will be heading up to higher altitudes later in September to participate in Driving for Kids, a fund raising event for a free Colorado camp for children with life threatening illnesses, one of several in the U.S. started by Paul Newman.

The elevation where I live is around 900 feet. Our round trip driving route of 2000 miles, will vary from our origination point of 900 feet elevation in Kansas City, Missouri, to around 5700 feet, and at some point, around 10,000 feet to get across the Rocky Mountains.

I can’t remember what adjustments are needed to compensate for the higher altitude.
Is it the fuel/air mixture, or the timing, or both?
What specific changes should I make once I reach, say, Denver at elevation 5280 feet?

Thanks.
Ron

p.s. Feel free to private message me if you are interested in supporting the Camp through this event.
 
The stock carbs actually adjust fairly well to changes in altitude, you don't _have_ to change anything. You might be able to get a little bit more power and better fuel mileage, by leaning the carbs and advancing the timing; but I'm not sure it's enough to worry about. I live near sea level, and drive up to around 6000 feet fairly often.

When I drove up to Breckenridge for VTR (highest 11,500; event was about 10,000), I tried making the adjustments. I could tell that "optimum" was a little different than before, but no "seat of the pants" difference before or after. Did run kind of crappy once I got back down, though.

Webers are a different story.
 
I routinely drive between Tucson (2722') and Mt Lemmon (9157') - w/o bothering to adjust anything. Same with occasional Colorado drive that went above 11000'. I will say that if your car is running rich down in the flatlands it will be much too rich at high altitude.

TR3driver said:
...Webers are a different story.
Click to expand...

We had a group drive in Eastern AZ (Devils Highway, tops out at 9355') where the cars with Webers took a different route and met us at the other end.
 
My experience has been the same as Geo and Randall. I live at about about 3100ft I take the TR4 over 10,900' Beartooth the pass on the way to Yellowstone Park. I also drive quite a bit in Wisconsin 600'. I have had in Victoria BC, sea level, several times. My TR4 has HS6's, it seems to run a bit rich at the top of the pass, but no problems. I had some Webers on it for short time, they are on the shelf in the shop, no fun at all, took all the wonderful flexibility away from the engine.
 
Back
Top