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Altitude Factor

Old Nov 18, 2008 | 04:48 PM
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Default Altitude Factor

Hey, as many of you know, i live in colorado and live at (when im home) 7500 feet and when im at school about 5400. I just wanted to see of there is an easy to use calculator to see how bad my performance is effected by the fact that i live 1+ miles above sea level. I also know that engines that have forced induction (ie turbo, supercharger,etc) are able to overcome much of the difference in altitude but since mine is N/A well i just wanted to see how bad it really is.

Thanks yall
 
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Old Nov 18, 2008 | 05:04 PM
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o2 sensors adjust for altitude, density of the gases coming out. I wouldn't expect to see much.
 
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Old Nov 18, 2008 | 05:06 PM
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ya i know they adjust but my question is probably more to do with the fact that the air at this alititude doesn't have the same amount of oxygen as air at sea level. wouldn't that make a big difference?
 
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Old Nov 18, 2008 | 05:09 PM
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maybe a little, but nothing major, I would suspect it would adjust my leaning out the gas going in.
 
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Old Nov 18, 2008 | 05:44 PM
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just slap a twin screw on that bitch and blame the altitude
 
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Old Nov 18, 2008 | 05:45 PM
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yeah i would if i had that kind of money just lying around.... idk i was looking at articles and it says that a n/a engine can lose 20% of its power at like 7000 feet.
 
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Old Nov 18, 2008 | 09:38 PM
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It's true your performance is suffering a little. from what I understand the computer is adjusting your A/F ratio as long as your o2's are functioning properly, so you should not have a lean condition at all. Its a bit like putting a smaller throttle body on, you're not hurting anything, but you're not reaching the power potential. I have seen like a calculation table that adjusts for this type of thing somewhere before but I dont remember where. But I know it does rob you of power, ask any real drag racer. ambient conditions affect an engine more than anything. A car that runs a 12 second quarter mile at sea level say on the east coast, might run a 13.2 in denver colorado.
 
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Old Nov 18, 2008 | 10:50 PM
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While the o2's do play a part in adjusting for altitude, the MAP sensor does most of the work. In fact you shouldn't see any performance losses due to speed density fuel injection and the MAP sensor. Every time you turn the key on and every time you go to wide-open-throttle the PCM updates the barometric pressure reading to compensate for altitude.
(one of the few perks of speed density over mass air...)
 
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Old Nov 18, 2008 | 11:25 PM
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Originally Posted by 00DakR/T
While the o2's do play a part in adjusting for altitude, the MAP sensor does most of the work. In fact you shouldn't see any performance losses due to speed density fuel injection and the MAP sensor. Every time you turn the key on and every time you go to wide-open-throttle the PCM updates the barometric pressure reading to compensate for altitude.
(one of the few perks of speed density over mass air...)
speaking of that........anyone ever heard of a mass air conversion for the daks? sure would be nicer to have for when i throw a 600 lift cam at the damn thing
 
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Old Nov 19, 2008 | 01:27 PM
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Originally Posted by 00DakR/T
While the o2's do play a part in adjusting for altitude, the MAP sensor does most of the work. In fact you shouldn't see any performance losses due to speed density fuel injection and the MAP sensor. Every time you turn the key on and every time you go to wide-open-throttle the PCM updates the barometric pressure reading to compensate for altitude.
(one of the few perks of speed density over mass air...)
well if it does that, why is it that when people run drag races at altitude, they are always lower and in some cases have to add time and mph in order to adjust for the less dense air?
 
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