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Old 06-01-2009, 12:17 AM   #10
AleroB888
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Quote:
Originally Posted by kwhauck View Post
daytona, you may want to note somewhere that supercharged and turboed cars are half factor for altitude correction....

Quote:
Originally Posted by AleroB888 View Post
I have reached the conclusion the NHRA is assuming that the boosted cars will be retuned when changing tracks, meaning that the owner will "turn up" the boost for a high altitude track, or decrease boost when going to lower altitudes.

On both occasions when I have kept the same tune and boost level, and ran in Denver and Kentucky at about the same temperatures, the difference has been about one full second, or a factor of about 0.93. That is almost exactly what NHRA says is the N/A factor.

Quote:
Originally Posted by kwhauck View Post
what about humidity factors greg, denver is a lot drier than kentucky


That's a less important variable, since there are times of the year in Kentucky that are fairly dry, and some times in Denver that are humid. In either place, if you have storms moving in, all bets are off, the barometric pressure can change, too.

It seems logical to me that there exists some optimum amount of humidity for performance. Not enough could increase heat, possibly leading to detonation, or too much could displace intake air, causing power loss..(what about water injection?)

But other things equal, in the E.T. range most of our cars run, you will gain about a second going to sea level from Denver, boosted or not, if you change nothing on the car.
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