High Altitude Driving

[robertm]

I have taken my 1981 998cc Mini on road trips that have included the 10,662' Vail pass and 11,158' Eisenhower Tunnel and on club drives in the Rocky Mountain Foothills to 8,000' and luckily I haven't experienced any drivability issues.

As for sluggish starts, I find that sometimes it feels like it suffers off the line. I have come up with an off-the-line-launch style of driving that usually feels better with no actual numbers, just feel.

If I just go to wide open throttle from a dead stop the car feels sluggish, but if I crack the throttle a little, get rolling at three or four miles per hour and then floor it I'm able to keep up with traffic and the acceleration feels nice.

I think sluggish starts are a combination of the the way the AP Automatic Transmission was designed and how it works and the way the SU HS4 carburetor works.

Once the car is moving it is a blast to drive.

I wounder if anyone with a Weber carburetor and AP Automatic Transmission can relate or has noticed a difference in off the line acceleration? 

[69hcode]

I noticed mine takes off a little better of I take off as you describe. I just don't get decent power until 1500 rpm's or so then it takes off great. I've got a 1275 in the works. Should take care of all those problems.

[richard1]

I hadn't noticed this, but should chime in. I live part time at 1200 ft above sea level and part time at 6000 ft. One of the biggest problems with cars that do not have computers and mass air flow sensors is adjusting the timing to the altitude.

First recognize that you loose 3% power for every 1000 ft above sea level, so at 11000 ft, you are already down 33%. (A turbo would make up for the first 6000 ft.)

As you go up, you need to advance the timing to get enough air into the cylinders for good power. As you go down you need to retard it or it will ping. I set up my Corvair at 6200 ft in town, but had to retard it for my house at 5600 ft. When I brought it to my other home at 1200 ft, I set it back more. Back in the days of no computers and MF, and I lived at 6200 ft, working anywhere from 800 ft to 15,000 ft, if I was in a hurry to get somewhere I usually stopped to adjust the timing a couple of times in the day.

The timing light will give you the correct timing for sea level and an engine in generally "normal" condition. Advance your timing to get the best idle, maybe twist it back a tiny bit, and accelerate hard. If it pings, twist it back a touch (maybe 1/8" increments) until it does not ping where you live. Mark it there. Then when you go to Vail or somewhere, you can advance it a bit if you want, or if you drop down into the plains you SHOULD retard it, but you can always come back to your home mark.

[notamini]

Wow Richard!
I had no idea you have been a Studebaker man. I love those cars. My dad also had a '50 'Bullet nose'. Of course, my favourite is the '63 Avanti followed by the Silver Hawk.

Mark
ON, Canada

[richard1]

Yep, my father bought the first one, a 50, in 59 for $25 on the condition that he never had to spend anything on maintenance. So my brother and I learned all we could and did all the maintenance.

Eventually I bought the 59 Silver Hawk in College. It had 200,000 miles on it when I sold it at the end of 64, driving across country for breaks or ski trips, mostly at 100 to 130 mph.

There is a 50 available here, but the guy wants $6000 for it and it needs about $10,000 worth of work, so not an option. And a 52 with less than 1200 miles, but they want $25,000. Crazy people.