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Discussion Starter #1
how much does elevation affect 1/4 mile times?
I go to lebannon valley and alot of people are telling me that the track there is several tenths slower than engishtown or atco because the elevation is higher.I found a calculator and entered all the info off my last time slip and it came back [email protected] but i ran a [email protected] at lebannon valley.
Lebannon vally is 1000ft above sea level i think?Would there really be that big of a difference?or are the DA calculaors b.s ?
:shakehead
 

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I race at two different tracks about 4 hours apart. One is 1/8 and the other 1/4. My 1/8 times are 7.85...my 1/8 at the 1/4 track is 8.05. Who knows, it's a bummer though.
 

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Yes there is a difference in elevation, our home track is at 3600ft and there is right at 6 tenths difference between us and sea level. I've tested it by running in San Antonio and Houston to see. NHRA has a correction factor table and while there are a LOT of people who don't believe in comparing corrected numbers, it is a very REAL difference. Combos that would easily go 12s at sea level are mid 13s here at best.

Now as far as density altitude, there is even a bigger difference and you need to take that into account as well.
 

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Discussion Starter #4
So for me to run 13.8 at97 and 1000ft above.
At englishtown raeway is only ithink 97ft above.
You think 13.0 at 101 is whered i'd be:evil:
 

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So for me to run 13.8 at97 and 1000ft above.
At englishtown raeway is only ithink 97ft above.
You think 13.0 at 101 is whered i'd be:evil:
Ha!! I am living your nightmare! I just transplanted to Dallas from Houston and let me tell you the DA makes a HUGE difference. A good factor for estimating times is areund .5 second/500 ft increase in altitude. My car is about a half tenth slower up here than back down in Houston. ( given the same DA's with no correction) Look up "DA calculator" on your favorite search engine and see for your self. By the way. My car is extremely consistant. I have plugged in the conditions on my timeslips from both Dallas and Houston and I am within less than a tenth per the calculator's logic. That is on roughly 30 passes compared.
 

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Lebanon Valley - 603'

Englishtown - 60' +/- depending on info

Atco - 99' - depending on info

New England - 90'

Above sea level , without the weather factor .
 

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I have run my car at 3 of the 4 tracks you mentioned. General rule of thumb is whatever you run at LVD subtract a tenth for NED or a tenth and a half for Etown with the weather conditions being the same.
Do not go by the weather info on LVD's timeslip. It has not been right all year. Usually the temp is way high. Last Saturday my slip said the DA was 4000' using the weather info I had and using a calculator it was closer to 1000'.
You are not going to see an 8 tenths increase in ET by going to Etown.
Weather plays more of a factor than the elevation difference between these tracks.

To Cobra 427, I think you meant to say .05 decrease in ET per 500' in DA.
.5 is half of a second.
 

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a higher actual elevation can in fact give you equal or better ET only when the humidity is under 12 percent.
...and the comparative track at a lower elevation has 50 percent or more humidity....

but as allways, you have to tune the fuel to take advantage of each.
 

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I have run my car at 3 of the 4 tracks you mentioned. General rule of thumb is whatever you run at LVD subtract a tenth for NED or a tenth and a half for Etown with the weather conditions being the same.
Do not go by the weather info on LVD's timeslip. It has not been right all year. Usually the temp is way high. Last Saturday my slip said the DA was 4000' using the weather info I had and using a calculator it was closer to 1000'.
You are not going to see an 8 tenths increase in ET by going to Etown.
Weather plays more of a factor than the elevation difference between these tracks.

To Cobra 427, I think you meant to say .05 decrease in ET per 500' in DA.
.5 is half of a second.


Umm. Woops. You are right. .05/500 ft. That was a pretty bad typeo on my part.
 

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[/B]

Umm. Woops. You are right. .05/500 ft. That was a pretty bad typeo on my part.
I figured it was a typo, but didn't want the OP to think he could see over a half second decrease in ET by going to a different track.
Using his time slip numbers it appeared he thought he could run a 13.0 compared to his 13.8. That is because the numbers on his slip are bad. I don't know why the track doesn't fix it. How hard could it be to get a thermometer that reads correctly?
 

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I figured it was a typo, but didn't want the OP to think he could see over a half second decrease in ET by going to a different track.
Using his time slip numbers it appeared he thought he could run a 13.0 compared to his 13.8. That is because the numbers on his slip are bad. I don't know why the track doesn't fix it. How hard could it be to get a thermometer that reads correctly?
Oh, I know. I never use the track data. Sometimes I wonder if the thermometers are mounted into the track surface.
 

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Here is a prime example why you cannot just assume blanket statemants. Yes I also said that NED was a faster track and I still think it is.

Went to LVD on 8-8-09 and ran 9.93 in the morning and finished up the day with a 9.98 hot laping the car at 3 in the afternoon. DA was between 1000 and 1100 feet.

The next weekend I went to NED 8-15-09 to make my license runs. Best my car would run was 10.01 and 10.03. Not good enough for the license, but why didn't I run "a tenth" better?
Two things.
1: in order to get my license I had to make a 330' pass, 2 1/8 mile passes and then 2 1/4 mile passes under the observation of the track officials. 330 was a piece of cake, then the 2 1/8 mile runs went off without a hitch. My 1/8 mile passes were the best the car has run in any weather. [email protected] is plenty fast enough for a 9 second 1/4. At that time of the day the DA was around 1200', but as the day wore on the temp went up. By the time I went to make my 1/4 mile passes the DA was just over 2000'.
2: This was also that UPR weekend and lots of street tire cars were there. Bald spots at the starting were getting larger throughout the day and my 60's were getting longer as the day went on. I wish the track would move the street tire cars out of the groove and not let them tear up the start line for the slick tired cars. The groove is not that important for the street tires.

I'll finish with this, weather and track conditions play a much bigger role than elevation.
 

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http://www.dragtimes.com/da-density-altitude-calculator.php?elevationcorrect=2000&et=10.01&mph=&correctetmph=Correct+ET+and+MPH

This is the DA calculator I have used. I'm not a big fan of "fabricated" numbers but it does put things into perspective. Also, when comparing the car from track to track my corrected times were, in most cases, within a tenth of each other. I will say that it has hit the nail on the head a few times when I referenced a few timeslips from Houston. It said my corrected times were SLOWER than what I ran.
 

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Discussion Starter #17
thats the same one i used and it said 13.1 lol..i dunno.going to the track again wed providing it does not rain.ill pos the new numbers up.it should be alot cooler out and the track conditions should be far better than my last runs.
 
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