altitude
- Thread starter SCOTT CAREY
- Start date
Rule of thumb that I've seen is about 3% per 1000ft. So approaching 20% loss at that altitude.
My house is at 6600ft
My house is at 6600ft
G
Guest
Guest
I'll pull out my density/altitude charts tomorrow. These are created for individual aircraft, but they should give some indication. If it was a hot day, that would also have an affect. These charts use altitude and temp as keys into take of distance and gross weight reductions due to increases in either and for aircraft the affect is significant. The affect on engine performance is the greatest, but there is also an affect on the lift created by the airfoils. Plural because some aircraft have a flying tail and density altitude can have an affect on the acceptable CG envelope.
Hi Guys,
I live in Johannesburg South Africa, alt 5500ft. Power on normal aspirated cars are down about 18% as Steve mentioned. We have specially developed fuels for this altitude with lower RON/octane ratings. Normally go down 2 sizes on the mains to lean the mixture and advance the timing 2-5 deg to allow more "burn" time. My day-2-day car is an Audi bi-turbo which of course doesn't care about altitude. You can get a chip for the engine management system on most modern cars that give you back 15%.
One great plus is that rust is no problem as oxidation is greatly reduced.
cheers
Dave
I live in Johannesburg South Africa, alt 5500ft. Power on normal aspirated cars are down about 18% as Steve mentioned. We have specially developed fuels for this altitude with lower RON/octane ratings. Normally go down 2 sizes on the mains to lean the mixture and advance the timing 2-5 deg to allow more "burn" time. My day-2-day car is an Audi bi-turbo which of course doesn't care about altitude. You can get a chip for the engine management system on most modern cars that give you back 15%.
One great plus is that rust is no problem as oxidation is greatly reduced.
cheers
Dave
G
Guest
Guest
Scott, I am sorry I couldn't find my Mooney manual which had the density altitude charts in it so I can't give you any quantitative information. Suffice it to say that heat and altitude can have a very significant affect on an engines performance.
As Dave pointed out, this is one of the major advantages of an engine management system with a barometric pressure sensor and charge air temperature sensor. The fuel maps or algorithym can compensate for changes in these and, in a closed loop system, trim the adjustments based on feed back from the O2 sensor(s). In a word Noproblemman.
As Dave pointed out, this is one of the major advantages of an engine management system with a barometric pressure sensor and charge air temperature sensor. The fuel maps or algorithym can compensate for changes in these and, in a closed loop system, trim the adjustments based on feed back from the O2 sensor(s). In a word Noproblemman.
My 1931 Dusenberg has an altimeter and the owners manual explains how to adjust the distributor advance as you drive up a mountian. Changing the oil is also very simple. Put a pan under the engine, open an easily reached valve,allow the oil to drain out, close the valve, add 12 quarts of 50W, and drive on. In 1931 they probably didn't bother with the pan...
Best
Jim
[ August 28, 2002: Message edited by: MK -IV J6 ]
Best
Jim
[ August 28, 2002: Message edited by: MK -IV J6 ]
