The altitude adjustment causes a 3% power drop per 1000 feet. Hope that helps. I live at an altitude of 5000 feet. Most people say take about a second of the 1/4 mile time at this altitude if you run around 14-16 secs.

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2000 Lightning Silver frost
Clear corners (Front only)
PSP Intake, JDM Chip, Bed Rug, Snuglid

 

Hey thanks Hilander! I heard that a temp drop of 10 degrees, is worth a full 10th of a second, I was wondering how close that is also??

 

WOW!! I live at 5000 feet as well. Your telling me we are losing close to 50 HP due to altitude?! Now I am getting excited about moving to sea level!!

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00 Black Lightning
JL Flip chip, PSP filter kit No ET's yet
00 Honda Civic
01 Pontiac Grand AM GT

AIM: jakeowen22

 

The problem with using a simple correction factor is that we have a blower on our trucks. The correction factors out there are typically for N/A engines which has no "help" via a blower, turbo or nitrous oxide.

The correction for elevation will be less for a supercharged engine, but even then, unless you know exactly how efficient the blower is, it will be next to impossible to derive a really accurate formula.

Sure, you'll pick up some, but not nearly as much as a N/A motor will.

I believe NHRA actually has some formulas for N/A engines and forced induction engines to help with this...I just don't have them in front of me.

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Wes Tarbox
90 LX 5.0 (10.69 @ 134.7)--597rwhp/590rwtq
96 Cobra (12.34 @ 115.8)--392rwhp/433rwtq
99 Lightning (13.20 @ 103.8)--364rwhp/447rwtq
00 Expedition XLT 5.4
http://hometown.aol.com/wa2fst/home.htm

[This message has been edited by WA 2 FST (edited 03-12-2001).]

 

I discussed this with others including Mike from Superchips on the Chip board. Not all agree that the supercharged vehicle is less effected by altitude. I also know of a stock 2000 L that ran low 15 secs here at 5000 feet. Link below.

https://www.f150online.com/f150board...ML/001538.html

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2000 Lightning Silver frost
Clear corners (Front only)
PSP Intake, JDM Chip, Bed Rug, Snuglid

[This message has been edited by Hilander (edited 03-12-2001).]

 

Do you high altitude fellows also have that special "High altitude" option in the list? Something about a sensor and valve or something. It was one of the few options besides a heater block for Lightnings.

Daniel

 

Daniel,

I bought my L new in November from a dealer in PA. I did not know anything about a high altitude version. Please let me know if you have any other info.

James

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2000 Lightning Silver frost
Clear corners (Front only)
PSP Intake, JDM Chip, Bed Rug, Snuglid

 

I know, I know, I'm not an L guy, however I do know a little about a supercharged engine having flown a flew planes with them. The main reason for using a supercharger is that it is more effective a higher altitudes. At higher altitudes the air is thinner, but add a blower and you're still able to get the same boost number at 12k ft as at sea level. The air has the same percentage of O2, but is much less dense, boost it back to 10 psi, same air as at sea level. Now, for the real sceptics out there, you are right. At some point there is not enough air for the blower to make up for the altitude, but up to the 3500-5000 feet you are talking about, you still have enough air for the blower.
And one last note, the air is less dense at altitude, so there is also less drag (resistance) while trying to cut a 7'x5' hole in the air (tucks do not have very low drag coefficient numbers).

[This message has been edited by whitestx (edited 03-12-2001).]

 

I was wondering if anybody knows the correction factors for altitude, temperature, humidity, barometric pressure, for 1/8 and 1/4 mile times???