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#101
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E63 P30, CL500 Sport
LOL.... still going.....
I really don't think it varies that much from run to run. When I went to the track, my time between runs was an average of 4 to 7 minutes. I think DA may have varied 50 to 150 ft at most, which would not affect the run that much. DA will generally vary minimally within a small interval of time (5-10 minutes). However, I do agree that in a couple of hours, the change will be a bit more dramatic.
I agree. In fact next time, I will take measurements at the launching stage and in between runs and throughout a couple of hours, and definately at different tracks. This should tell us how much variance between runs and throughout the night. But after collecting all this data, I'll let you guys deal with all the analysis....
Actually he did. And the calculator gave a much smaller adjustment to the SAC results than to the LACR results. And his results at SAC were very very close to what the calculator corrected. Again, I'm not saying 100% accuracy, but at least 90 to 95% due to the slight variance in input data as you mentioned.
And I'm not disagreeing with you on that point. I stated before in previous posts that all a "corrected" time means is that a given car is potentially able to run a different time in better or worse conditions. That corrected time can be better or worse based on different weather conditions. That is why it is very important to note DA.
I am trying, but weather is killing it for me over here. The average temperature is 105 degrees Combine that with high DA and crappy air, you've got one big road block. But I still went a couple of times and was able to run 13.0 and 12.9. And by the way, 2 stock E55s ran with me that night and got 13.3 and 13.4 seconds, and before you ask, yes one of them had just changed the pump a month ago. Also a stage 1 car ran 12.4 seconds. The next best track is about 5 hours away, but still not as good as east-coast tracks. But as always, I will keep trying.
Now lets put all this DA stuff aside for a moment; when are you going to tell me your secret for launching the car.... How do you get this super-fast sub 12 second runs all the time. Give me something....
I am trying, but weather is killing it for me over here. The average temperature is 105 degrees Combine that with high DA and crappy air, you've got one big road block. But I still went a couple of times and was able to run 13.0 and 12.9. And by the way, 2 stock E55s ran with me that night and got 13.3 and 13.4 seconds, and before you ask, yes one of them had just changed the pump a month ago. Also a stage 1 car ran 12.4 seconds. The next best track is about 5 hours away, but still not as good as east-coast tracks. But as always, I will keep trying.
Now lets put all this DA stuff aside for a moment; when are you going to tell me your secret for launching the car.... How do you get this super-fast sub 12 second runs all the time. Give me something....
Last edited by MB_Forever; 09-08-2007 at 04:13 PM.
#102
MBWorld Fanatic!
Thread Starter
You need to follow your on advice, but besides just reading you need to comprehend. Here is another link on how true altitute is measured, ie - elevation. http://www.esri.com/news/arcuser/0703/geoid1of3.html
Go to one of the tracks you listed with a hand held GPS and see what it displays as altitude not pressure altitude because some GPS have an option for both, pilot's use pressure altitude while true altitude is the actual distance from sea level which thanks to the wonders and advancements in GPS technology has been made a lot easier to read. Then compare that to your DA on a summer day and you will see the difference between altitude and predicted altitude. There are very few places in the world were the GPS is not accurate and can be off because of the earths shape, lucky for us the continental US is not one of them. This has already been explained to you in my recent post you just don't comprehend.
Here is the track info from Amarillo Texas once again look below were it list elevation
Amarillo Dragway
Amarillo, TX
Schedule · News & Results · Points
Track Specifications
Configuration: Dragstrip
Length: 1/4 mi.
Surface: Asphalt/Concrete Pad
Sunday
E.T. Brackets
Friday
TNT
Saturday
Super Street Shooutout Series
Travel Information
National Speedway Directory Directions:
Located 7 miles south of Amarillo between Washington and Osage streets
View Map | Find Lodging
Notes:
Camping Allowed.
Contact Information
altitudes.
Promoter: Norm and Cat Henson, owners
Mailing Address: 12955 Burlington Rd.
Amarillo, TX 79118
You did notice it does not say track da correct. Just think about this I live in south Florida not to far away from the Ocean, my house elevation according to my survey is 13 ft my GPS says 12.7, yet on a hot muggy day in my back yard the DA will read from 1700 to 2600 ft if the weather is bad enough even 3000 ft. Do you still think density altitude is true altitude ? I have given you the definition of true altitude before several times, maybe now you can understand.
Just in case you want to do your own da calculation the nearest Airport to me is Homestead regional airport.
Go to one of the tracks you listed with a hand held GPS and see what it displays as altitude not pressure altitude because some GPS have an option for both, pilot's use pressure altitude while true altitude is the actual distance from sea level which thanks to the wonders and advancements in GPS technology has been made a lot easier to read. Then compare that to your DA on a summer day and you will see the difference between altitude and predicted altitude. There are very few places in the world were the GPS is not accurate and can be off because of the earths shape, lucky for us the continental US is not one of them. This has already been explained to you in my recent post you just don't comprehend.
Here is the track info from Amarillo Texas once again look below were it list elevation
Amarillo Dragway
Amarillo, TX
Schedule · News & Results · Points
Track Specifications
Configuration: Dragstrip
Length: 1/4 mi.
Surface: Asphalt/Concrete Pad
Sunday
E.T. Brackets
Friday
TNT
Saturday
Super Street Shooutout Series
Travel Information
National Speedway Directory Directions:
Located 7 miles south of Amarillo between Washington and Osage streets
View Map | Find Lodging
Notes:
Camping Allowed.
PHP Code:
[B]Track elevation 3,700 ft[/B]. TNT Fridays: 8 to midnight. Super Street Shootout Series Sat. 9 - midnight. ET Brackets on specific dates only.Too bad GPS, usgs survey lists the track at 3646 not 3700, that measurement is from a rounded number taken from SAE JRe13 "pressure Altitude correction factors" amount of O2 in the atmosphere at known
altitudes.
Promoter: Norm and Cat Henson, owners
Mailing Address: 12955 Burlington Rd.
Amarillo, TX 79118
You did notice it does not say track da correct. Just think about this I live in south Florida not to far away from the Ocean, my house elevation according to my survey is 13 ft my GPS says 12.7, yet on a hot muggy day in my back yard the DA will read from 1700 to 2600 ft if the weather is bad enough even 3000 ft. Do you still think density altitude is true altitude ? I have given you the definition of true altitude before several times, maybe now you can understand.
Just in case you want to do your own da calculation the nearest Airport to me is Homestead regional airport.
I understand all of this very well, but you cannot give me a definition of something that is not applicable to this discussion.
The NHRA TABLE
1. It is from SAE.ORG
2. The NHRA table uses "pressure altitude" adjustment factors
3. The Elevation is known , but the "Adjustment" the coefficient is FROM PRESSURE ALTITUDE, not Geospatial or MSL or anything else.
Once again your car unless you turn off the bottle is not subject to any adjustment, even if you ran on the top of Pikes Peak.
Enzom my car actually ran a better trap than the DA calc predicted but it was a tad slower ET... I had a .23 difference in 60 ft times. So yeah my best run at sea level is yet to come.....
We all agree DA is important
It is a great tool, to help a driver determine how his car performed.
It is also a great tool for a national comparison of cars and the drivers that drive em.
If the DA is less than 500 feet it effects the run very little if at all. I really only see a sharp decline if DA is above 1700. Jackson's Audi was called slow by many of the members here cause he was running at LACR. Now he is racing modded cars back east and doing very very well. Jackson knows about DA and also runs both coasts so his car is a great median of data.
1. Jacksons Audi S4 at LACR is likely 1.5 seconds slower and traps 10 mph less., thats a fact. Take his LACR time slip and compare it to a turboed S4 in NJ, and his car is much much slower, like comparing a jetta and a 997 TT.
We know correction works because Jackson's corrected times matchup nicely with the times he actually runs in the East.
12.5 vs 11.2 corrected
11.4vs 11.4 it works everytime and is very accurate.
How many of you guys against the corrections have EVER RUN at ALTITUDE!
NHRA ALTITUDE CORRECTION FACTORS
Stock & Super Stock
Convert to Sea Level Convert to Altitude
Track Name Alt ET MPH ET MPH
DIVISION 4
Amarillo, TX 3700 .9549 1.0479 1.0472 .9543
Roswell, NM 3700 .9549 1.0479 1.0472 .9543
DIVISION 5
Denver, CO 5800 .9276 1.0773 1.0781 .9282
Douglas, WY 4900 .9393 1.0647 1.0646 .9392
Grand Junction, CO 4800 .9406 1.0633 1.0632 .9405
Great Bend, KS 1900 .9783 1.0227 1.0222 .9778
Julesburg, CO 3500 .9575 1.0451 1.0444 .9568
Pierre, S.D. 1700 .9809 1.0199 1.0195 .9805
Pueblo, CO 4900 .9393 1.0647 1.0646 .9392
DIVISION 6
Acton, MT 3700 .9549 1.0479 1.0472 .9543
Anaconda, MT 5100 .9367 1.0675 1.0676 .9368
Ashcroft, CAN 1700 .9809 1.0199 1.0195 .9805
Boise, ID 2700 .9679 1.0339 1.0332 .9672
Lewistown, MT 4100 .9497 1.0535 1.0530 .9492
Medicine Hat, CAN 2400 .9718 1.0297 1.0290 .9712
Prince George, BC 2200 .9744 1.0269 1.0263 .9738
Saskatoon, CAN 1600 .9822 1.0185 1.0181 .9818
DIVISION 7
Albuquerque 5400 .9328 1.0717 1.0720 .9331
Fallon, NV 4000 .9510 1.0521 1.0515 .9505
Inyokern, CA 2400 .9718 1.0297 1.0290 .9712
Las Vegas, NV 2100 .9757 1.0255 1.0249 .9751
Palmdale, CA 2700 .9679 1.0339 1.0332 .9672
Salt Lake, UT 4400 .9458 1.0577 1.0573 .9454
Tucson, AZ 3000 .9640 1.0381 1.0373 .9633
If you look and study the table the ratio is as follows
AT 1600 feet the O2 level , the amount of O2 in the atmosphere is a factor of .9822 less than at SEA LEVEL.
The O2 level drops at a rate of .013per 1000 feet.
The ratio is the same for MPH. As altitude increases the ratio increases
This is a "pressure altitude table" and the "adjustments" on the DA calculation ARE IDENTICAL to the NHRA table. We can ascertain this by doing the calculation backward.
The math , , the equation 100% non variable, input accurate weather data, ET and trap and you will have an idea of what the car capable of in SAE condition. The more I read the more I am convinced , show me the calculator being completely off and I will never correct again, it will only be off if you input bogus data. Temp at the track and at an airport in the same zip is not going to be variant by more than a few degrees, and this can easily be checked by taking both measurements. Its a tool and some may never choose to use it, just as many do not choose to delete the leather AMG seats, or take out the command system and replace the battery, or buy 18 lb rims.. we all have our routine and , I am quite comfy with mine.
Last edited by juicee63; 09-08-2007 at 05:03 PM.
#103
MBWorld Fanatic!
LOL.... still going.....
I really don't think it varies that much from run to run. When I went to the track, my time between runs was an average of 4 to 7 minutes. I think DA may have varied 50 to 150 ft at most, which would not affect the run that much. DA will generally vary minimally within a small interval of time (5-10 minutes). However, I do agree that in a couple of hours, the change will be a bit more dramatic.
I agree. In fact next time, I will take measurements at the launching stage and in between runs and throughout a couple of hours, and definately at different tracks. This should tell us how much variance between runs and throughout the night. But after collecting all this data, I'll let you guys deal with all the analysis....
Actually he did. And the calculator gave a much smaller adjustment to the SAC results than to the LACR results. And his results at SAC were very very close to what the calculator corrected. Again, I'm not saying 100% accuracy, but at least 90 to 95% due to the slight variance in input data as you mentioned.
And I'm not disagreeing with you on that point. I stated before in previous posts that all a "corrected" time means is that a given car is potentially able to run a different time in better or worse conditions. That corrected time can be better or worse based on different weather conditions. That is why it is very important to note DA.
I am trying, but weather is killing it for me over here. The average temperature is 105 degrees Combine that with high DA and crappy air, you've got one big road block. But I still went a couple of times and was able to run 13.0 and 12.9. And by the way, 2 stock E55s ran with me that night and got 13.3 and 13.4 seconds, and before you ask, yes one of them had just changed the pump a month ago. Also a stage 1 car ran 12.4 seconds. The next best track is about 5 hours away, but still not as good as east-coast tracks. But as always, I will keep trying.
Now lets put all this DA stuff aside for a moment; when are you going to tell me your secret for launching the car.... How do you get this super-fast sub 12 second runs all the time. Give me something....
I really don't think it varies that much from run to run. When I went to the track, my time between runs was an average of 4 to 7 minutes. I think DA may have varied 50 to 150 ft at most, which would not affect the run that much. DA will generally vary minimally within a small interval of time (5-10 minutes). However, I do agree that in a couple of hours, the change will be a bit more dramatic.
I agree. In fact next time, I will take measurements at the launching stage and in between runs and throughout a couple of hours, and definately at different tracks. This should tell us how much variance between runs and throughout the night. But after collecting all this data, I'll let you guys deal with all the analysis....
Actually he did. And the calculator gave a much smaller adjustment to the SAC results than to the LACR results. And his results at SAC were very very close to what the calculator corrected. Again, I'm not saying 100% accuracy, but at least 90 to 95% due to the slight variance in input data as you mentioned.
And I'm not disagreeing with you on that point. I stated before in previous posts that all a "corrected" time means is that a given car is potentially able to run a different time in better or worse conditions. That corrected time can be better or worse based on different weather conditions. That is why it is very important to note DA.
I am trying, but weather is killing it for me over here. The average temperature is 105 degrees Combine that with high DA and crappy air, you've got one big road block. But I still went a couple of times and was able to run 13.0 and 12.9. And by the way, 2 stock E55s ran with me that night and got 13.3 and 13.4 seconds, and before you ask, yes one of them had just changed the pump a month ago. Also a stage 1 car ran 12.4 seconds. The next best track is about 5 hours away, but still not as good as east-coast tracks. But as always, I will keep trying.
Now lets put all this DA stuff aside for a moment; when are you going to tell me your secret for launching the car.... How do you get this super-fast sub 12 second runs all the time. Give me something....
As far as launching, I am not sure that what works for the 55 will work for the 63. It took me a while to learn that the car did not like any brake-torquing. I let go of the brake fully and roll hard into the throttle off idle. (ESP on).
Pre-staging, I drop my rears to 22 lbs. and do a burnout (ESP off) in the waterbox. Shallow stage and set the suspension to comfort.
It took me forever to get into the 11's. Being patient allowed me to run 1.7 60' times pretty regularly. And that was the difference between all of my 12.0's and 12.1's and getting into the 11's.
When I finally do make it to the track with Venom (maybe this Friday), he and I will swap cars and see if our techniques can work in both cars. (Assuming he doesn't mind me doing a burnout with his ride.)
#104
MBWorld Fanatic!
Thread Starter
Nice post.
As far as launching, I am not sure that what works for the 55 will work for the 63. It took me a while to learn that the car did not like any brake-torquing. I let go of the brake fully and roll hard into the throttle off idle. (ESP on).
Pre-staging, I drop my rears to 22 lbs. and do a burnout (ESP off) in the waterbox. Shallow stage and set the suspension to comfort.
It took me forever to get into the 11's. Being patient allowed me to run 1.7 60' times pretty regularly. And that was the difference between all of my 12.0's and 12.1's and getting into the 11's.
When I finally do make it to the track with Venom (maybe this Friday), he and I will swap cars and see if our techniques can work in both cars. (Assuming he doesn't mind me doing a burnout with his ride.)
As far as launching, I am not sure that what works for the 55 will work for the 63. It took me a while to learn that the car did not like any brake-torquing. I let go of the brake fully and roll hard into the throttle off idle. (ESP on).
Pre-staging, I drop my rears to 22 lbs. and do a burnout (ESP off) in the waterbox. Shallow stage and set the suspension to comfort.
It took me forever to get into the 11's. Being patient allowed me to run 1.7 60' times pretty regularly. And that was the difference between all of my 12.0's and 12.1's and getting into the 11's.
When I finally do make it to the track with Venom (maybe this Friday), he and I will swap cars and see if our techniques can work in both cars. (Assuming he doesn't mind me doing a burnout with his ride.)
I hate to point this out but it is valid in this discussion and shows how accurate the calculator is
http://www.dragtimes.com/2005-Merced...ecs-11697.html
Here is one of your sub 12 second runs. It shows a 4 minute difference as to the weather input and lists the exact same barometric and temp as the slip. Using your slip as an example which of your two runs was better to you? Looks like whats on the slip holds true regardless of an adjustment for negative DA. Your actual fastest run was you best corrected time as well. Once again for information only, your car is VERY FAST and likely can run 12 seconds all day long but going sub 12 is going to take a negative DA, or a 1.6 60ft, or a mod, weight reduction. Great runs and you are a truly consistant runner. BTW your times are even less adjusted than listed but the trend is the same as DA goes more negative your car gets FASTER. It effects your car to a lessor degree so this calc would require a bit more work. You would need multiply the DA by .50 to get a true # for a SC engine. Your actual and corrected times are closer than what is presented below. This was just to show the accuracy of input and what info you could gain by doing this. Obviously just noting the -1000 ft would tell people your run was aided by atmosphere, that would be enough. Your actual corrected time is 11.915@117.5 WOW. My car at this DA may hit 12.1 or so
The closest weather results for 03/31/2007 at 09:59 am
Time recorded 9:55 AM
Temperature °F 48.2
Dew Point °F 19.4
Altimeter Setting 30.27 Inches Mercury
Absolute Pressure: 30.19 Inches
Density Altitude: -959 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.892 (sec) @ 117.72.22 (MPH)
Corrected ET to Sea Level:
12.012 (sec) @ 116.506 (MPH)
The closest weather results for 03/31/2007 at 09:07 am
Time recorded 9:15 AM
Temperature °F 46.4
Dew Point °F 21.2
Altimeter Setting 30.25 Inches Mercury
Absolute Pressure: 30.17 Inches
Density Altitude: -1054.7 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.850 (sec) @ 118.17 (MPH)
Corrected ET to Sea Level:
11.981 (sec) @ 116.83 (MPH)
This is where the correction table the NHRA table is derived RFLOW
Standard Atmospheric Conditions Altitude
(feet) Pressure
(in. Hg) Temp.
(F°) Density
(%)
sealevel 29.92 59.0 100
2,000 27.82 51.9 94.3
4,000 25.84 44.7 88.8
6,000 23.98 37.6 83.6
8,000 22.22 30.5 78.6
10,000 20.57 23.3 73.8
12,000 19.02 16.2 69.3
14,000 17.57 9.1 65.0
16,000 16.21 1.9 60.9
Last edited by juicee63; 09-08-2007 at 07:13 PM.
#105
MBWorld Fanatic!
Thread Starter
Nah dude, I work with the guys at IHRA. NHRA runs coast to coast and IHRA is mainly in the East/Midwest and into Canada. Plans in the works to expand out west in the future though I am sure.
My only input on the DA issue is that I use it more as a tool rather than ET equalizer. Was heading down to Rudyrono's Vegas strip and the blazing heat plus his actual alt made the DA 4300, which is EXACTLY what my altitude was at my track back home. No sense in wasting 4 hour drive to pull the exact same times down there so we called it off.
It does make you feel a little better to use it sometimes when you tank at higher altitudes. I can't tell you how bummed I was when I pulled 12.7 after my K2 with LSD install with DR's. Had guys coming out of the woodwork telling me to use the NHRA calc to see what she would do down at Sacto. You gotta feel for us higher alt guys. NHRA calc can be our only hope sometimes.
It's mainly a west thing as we have these pesky 12-14,000 footers that get in our way sometimes.
My only input on the DA issue is that I use it more as a tool rather than ET equalizer. Was heading down to Rudyrono's Vegas strip and the blazing heat plus his actual alt made the DA 4300, which is EXACTLY what my altitude was at my track back home. No sense in wasting 4 hour drive to pull the exact same times down there so we called it off.
It does make you feel a little better to use it sometimes when you tank at higher altitudes. I can't tell you how bummed I was when I pulled 12.7 after my K2 with LSD install with DR's. Had guys coming out of the woodwork telling me to use the NHRA calc to see what she would do down at Sacto. You gotta feel for us higher alt guys. NHRA calc can be our only hope sometimes.
It's mainly a west thing as we have these pesky 12-14,000 footers that get in our way sometimes.
We are going TO SAC SOOON BRO!!!Lets get a group together Mid Oct
#106
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E63 P30, CL500 Sport
Lets also try to organize an event at Famoso in the winter. The weather gets really cold there and should be awsome for drag racing......
Adam, are you reading this?
#107
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E55
Whats up with Famoso? Their test n tune schedule is looking pretty sad for the rest if the year!
Im ready for Famoso,Speedworld or Sac soon as the weather get better.
#108
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E63 P30, CL500 Sport
Famoso has no more open test n tune nights until March (I think) The rest of the year is reserved for certain local racing events The only chance is to rent the track on a week day I say lets do it in October sometime when the weather is COLD
Last edited by MB_Forever; 09-08-2007 at 09:11 PM.
#109
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old daily driver '07 E63(gone); new dd '14 750xi; 2013 Viper GTS
Nice post.
........ Shallow stage and set the suspension to comfort.
When I finally do make it to the track with Venom (maybe this Friday), he and I will swap cars and see if our techniques can work in both cars. (Assuming he doesn't mind me doing a burnout with his ride.)
........ Shallow stage and set the suspension to comfort.
When I finally do make it to the track with Venom (maybe this Friday), he and I will swap cars and see if our techniques can work in both cars. (Assuming he doesn't mind me doing a burnout with his ride.)
You should only deep stage when bracket racing and you need a dial in.
As far as me minding a burnout in my car, c'mon Enzom..it's only a car. Besides I trust you.
#110
MBWorld Fanatic!
Thread Starter
I also shallow stage my car hoping a very small roll-out won't trip a red light and I could improve the 60' time.
You should only deep stage when bracket racing and you need a dial in.
As far as me minding a burnout in my car, c'mon Enzom..it's only a car. Besides I trust you.
You should only deep stage when bracket racing and you need a dial in.
As far as me minding a burnout in my car, c'mon Enzom..it's only a car. Besides I trust you.
#111
MBWorld Fanatic!
I understand all of this very well, but you cannot give me a definition of something that is not applicable to this discussion.
The NHRA TABLE
1. It is from SAE.ORG
2. The NHRA table uses "pressure altitude" adjustment factors
3. The Elevation is known , but the "Adjustment" the coefficient is FROM PRESSURE ALTITUDE, not Geospatial or MSL or anything else.
Once again your car unless you turn off the bottle is not subject to any adjustment, even if you ran on the top of Pikes Peak.
Enzom my car actually ran a better trap than the DA calc predicted but it was a tad slower ET... I had a .23 difference in 60 ft times. So yeah my best run at sea level is yet to come.....
We all agree DA is important
It is a great tool, to help a driver determine how his car performed.
It is also a great tool for a national comparison of cars and the drivers that drive em.
If the DA is less than 500 feet it effects the run very little if at all. I really only see a sharp decline if DA is above 1700. Jackson's Audi was called slow by many of the members here cause he was running at LACR. Now he is racing modded cars back east and doing very very well. Jackson knows about DA and also runs both coasts so his car is a great median of data.
1. Jacksons Audi S4 at LACR is likely 1.5 seconds slower and traps 10 mph less., thats a fact. Take his LACR time slip and compare it to a turboed S4 in NJ, and his car is much much slower, like comparing a jetta and a 997 TT.
We know correction works because Jackson's corrected times matchup nicely with the times he actually runs in the East.
12.5 vs 11.2 corrected
11.4vs 11.4 it works everytime and is very accurate.
How many of you guys against the corrections have EVER RUN at ALTITUDE!
NHRA ALTITUDE CORRECTION FACTORS
Stock & Super Stock
Convert to Sea Level Convert to Altitude
Track Name Alt ET MPH ET MPH
DIVISION 4
Amarillo, TX 3700 .9549 1.0479 1.0472 .9543
Roswell, NM 3700 .9549 1.0479 1.0472 .9543
DIVISION 5
Denver, CO 5800 .9276 1.0773 1.0781 .9282
Douglas, WY 4900 .9393 1.0647 1.0646 .9392
Grand Junction, CO 4800 .9406 1.0633 1.0632 .9405
Great Bend, KS 1900 .9783 1.0227 1.0222 .9778
Julesburg, CO 3500 .9575 1.0451 1.0444 .9568
Pierre, S.D. 1700 .9809 1.0199 1.0195 .9805
Pueblo, CO 4900 .9393 1.0647 1.0646 .9392
DIVISION 6
Acton, MT 3700 .9549 1.0479 1.0472 .9543
Anaconda, MT 5100 .9367 1.0675 1.0676 .9368
Ashcroft, CAN 1700 .9809 1.0199 1.0195 .9805
Boise, ID 2700 .9679 1.0339 1.0332 .9672
Lewistown, MT 4100 .9497 1.0535 1.0530 .9492
Medicine Hat, CAN 2400 .9718 1.0297 1.0290 .9712
Prince George, BC 2200 .9744 1.0269 1.0263 .9738
Saskatoon, CAN 1600 .9822 1.0185 1.0181 .9818
DIVISION 7
Albuquerque 5400 .9328 1.0717 1.0720 .9331
Fallon, NV 4000 .9510 1.0521 1.0515 .9505
Inyokern, CA 2400 .9718 1.0297 1.0290 .9712
Las Vegas, NV 2100 .9757 1.0255 1.0249 .9751
Palmdale, CA 2700 .9679 1.0339 1.0332 .9672
Salt Lake, UT 4400 .9458 1.0577 1.0573 .9454
Tucson, AZ 3000 .9640 1.0381 1.0373 .9633
If you look and study the table the ratio is as follows
AT 1600 feet the O2 level , the amount of O2 in the atmosphere is a factor of .9822 less than at SEA LEVEL.
The O2 level drops at a rate of .013per 1000 feet.
The ratio is the same for MPH. As altitude increases the ratio increases
This is a "pressure altitude table" and the "adjustments" on the DA calculation ARE IDENTICAL to the NHRA table. We can ascertain this by doing the calculation backward.
The math , , the equation 100% non variable, input accurate weather data, ET and trap and you will have an idea of what the car capable of in SAE condition. The more I read the more I am convinced , show me the calculator being completely off and I will never correct again, it will only be off if you input bogus data. Temp at the track and at an airport in the same zip is not going to be variant by more than a few degrees, and this can easily be checked by taking both measurements. Its a tool and some may never choose to use it, just as many do not choose to delete the leather AMG seats, or take out the command system and replace the battery, or buy 18 lb rims.. we all have our routine and , I am quite comfy with mine.
The NHRA TABLE
1. It is from SAE.ORG
2. The NHRA table uses "pressure altitude" adjustment factors
3. The Elevation is known , but the "Adjustment" the coefficient is FROM PRESSURE ALTITUDE, not Geospatial or MSL or anything else.
Once again your car unless you turn off the bottle is not subject to any adjustment, even if you ran on the top of Pikes Peak.
Enzom my car actually ran a better trap than the DA calc predicted but it was a tad slower ET... I had a .23 difference in 60 ft times. So yeah my best run at sea level is yet to come.....
We all agree DA is important
It is a great tool, to help a driver determine how his car performed.
It is also a great tool for a national comparison of cars and the drivers that drive em.
If the DA is less than 500 feet it effects the run very little if at all. I really only see a sharp decline if DA is above 1700. Jackson's Audi was called slow by many of the members here cause he was running at LACR. Now he is racing modded cars back east and doing very very well. Jackson knows about DA and also runs both coasts so his car is a great median of data.
1. Jacksons Audi S4 at LACR is likely 1.5 seconds slower and traps 10 mph less., thats a fact. Take his LACR time slip and compare it to a turboed S4 in NJ, and his car is much much slower, like comparing a jetta and a 997 TT.
We know correction works because Jackson's corrected times matchup nicely with the times he actually runs in the East.
12.5 vs 11.2 corrected
11.4vs 11.4 it works everytime and is very accurate.
How many of you guys against the corrections have EVER RUN at ALTITUDE!
NHRA ALTITUDE CORRECTION FACTORS
Stock & Super Stock
Convert to Sea Level Convert to Altitude
Track Name Alt ET MPH ET MPH
DIVISION 4
Amarillo, TX 3700 .9549 1.0479 1.0472 .9543
Roswell, NM 3700 .9549 1.0479 1.0472 .9543
DIVISION 5
Denver, CO 5800 .9276 1.0773 1.0781 .9282
Douglas, WY 4900 .9393 1.0647 1.0646 .9392
Grand Junction, CO 4800 .9406 1.0633 1.0632 .9405
Great Bend, KS 1900 .9783 1.0227 1.0222 .9778
Julesburg, CO 3500 .9575 1.0451 1.0444 .9568
Pierre, S.D. 1700 .9809 1.0199 1.0195 .9805
Pueblo, CO 4900 .9393 1.0647 1.0646 .9392
DIVISION 6
Acton, MT 3700 .9549 1.0479 1.0472 .9543
Anaconda, MT 5100 .9367 1.0675 1.0676 .9368
Ashcroft, CAN 1700 .9809 1.0199 1.0195 .9805
Boise, ID 2700 .9679 1.0339 1.0332 .9672
Lewistown, MT 4100 .9497 1.0535 1.0530 .9492
Medicine Hat, CAN 2400 .9718 1.0297 1.0290 .9712
Prince George, BC 2200 .9744 1.0269 1.0263 .9738
Saskatoon, CAN 1600 .9822 1.0185 1.0181 .9818
DIVISION 7
Albuquerque 5400 .9328 1.0717 1.0720 .9331
Fallon, NV 4000 .9510 1.0521 1.0515 .9505
Inyokern, CA 2400 .9718 1.0297 1.0290 .9712
Las Vegas, NV 2100 .9757 1.0255 1.0249 .9751
Palmdale, CA 2700 .9679 1.0339 1.0332 .9672
Salt Lake, UT 4400 .9458 1.0577 1.0573 .9454
Tucson, AZ 3000 .9640 1.0381 1.0373 .9633
If you look and study the table the ratio is as follows
AT 1600 feet the O2 level , the amount of O2 in the atmosphere is a factor of .9822 less than at SEA LEVEL.
The O2 level drops at a rate of .013per 1000 feet.
The ratio is the same for MPH. As altitude increases the ratio increases
This is a "pressure altitude table" and the "adjustments" on the DA calculation ARE IDENTICAL to the NHRA table. We can ascertain this by doing the calculation backward.
The math , , the equation 100% non variable, input accurate weather data, ET and trap and you will have an idea of what the car capable of in SAE condition. The more I read the more I am convinced , show me the calculator being completely off and I will never correct again, it will only be off if you input bogus data. Temp at the track and at an airport in the same zip is not going to be variant by more than a few degrees, and this can easily be checked by taking both measurements. Its a tool and some may never choose to use it, just as many do not choose to delete the leather AMG seats, or take out the command system and replace the battery, or buy 18 lb rims.. we all have our routine and , I am quite comfy with mine.
What don't you understand about taking a fixed track elevation and correcting for sea level.
Take great Great Bend, Kansas the average city elevation is 1849 ft the nhra uses 1900 ft which is probably the elevation that would be displayed on a GPS at the track and then corrects for sea level. The only way the elevation can change is by earth quake it is not dependent on the weather. The da takes the weather into account which the nhra does not care about and you want to know why because everyone racing at said track is affected by the weather. At different times of the day the weather(DA) will be better or worse but the elevation will remain constant and is the only thing they feel has to be corrected to level the playing field from venue to venue.
Moroso is 21 ft or so above sea level yet with a da calculator you can see numbers as high as 3000 ft, why does the nhra not list moroso as an altitude facility or Gainesville, Florida which can also have Da's in the 3000's, Two tracks that I have personally raced at with those da's. The answer is simple the track elevation does not warrant it and that is all the nhra cares about.
The nhra recently raised the minimum required elevation to be considered an altitude facility to 1700ft.
Go to the beach on a very hot summer day and take a da meter and see what it tells you and then compare that to a gps reading and see the difference.
One is true altitude the other is calculated altitude. Take gps and da readings in the morning at noon and late at night and tell me which readings change and which one stays the same.
Anything that is calculated based on different inputs is subject to possible errors That is why they use a constant elevation for said venue and correct to sea level.
You want to see your da meter be off come to south Florida and I will run my car with -out nitrous but with ice water in my reservoir flowing through the ic and see how off your da is, yes using the 1/2 correction for supercharged engines. I will pay all of your expenses to and from if I'm wrong.
Last edited by rflow306; 09-08-2007 at 10:01 PM.
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E55
A track rental would be sweet.We need to call and get some facts.Need to do a weather history report for that area and see what a good times is to rent the track without a chance of rain,also look for cool air temps.
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Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
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Ohhhhhh.Ok,how about this one.2 identical stock cars,but ones running very rich and the other is close to perfect.Now how do you adjust their DA's? Which car would benefit more from the DA correction or would they be equal? If they actuall ran in the better calculated DA's conditions.
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Enzom, why are you and Venom not on the MIR track rental list? You guys are close enuff that you should sign up. Sleepy and a bunch of other NY'ers are coming down. You guys should try to make it down, it should be a blast.
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
Looks very good in black, how does it feel ? Are you following my recommended break in procedure to drive it like you stole it?
#116
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Juice
What don't you understand about taking a fixed track elevation and correcting for sea level.
Take great Great Bend, Kansas the average city elevation is 1849 ft the nhra uses 1900 ft which is probably the elevation that would be displayed on a GPS at the track and then corrects for sea level. The only way the elevation can change is by earth quake it is not dependent on the weather. The da takes the weather into account which the nhra does not care about and you want to know why because everyone racing at said track is affected by the weather. At different times of the day the weather(DA) will be better or worse but the elevation will remain constant and is the only thing they feel has to be corrected to level the playing field from venue to venue.
Moroso is 21 ft or so above sea level yet with a da calculator you can see numbers as high as 3000 ft, why does the nhra not list moroso as an altitude facility or Gainesville, Florida which can also have Da's in the 3000's, Two tracks that I have personally raced at with those da's. The answer is simple the track elevation does not warrant it and that is all the nhra cares about.
The nhra recently raised the minimum required elevation to be considered an altitude facility to 1700ft.
Go to the beach on a very hot summer day and take a da meter and see what it tells you and then compare that to a gps reading and see the difference.
One is true altitude the other is calculated altitude. Take gps and da readings in the morning at noon and late at night and tell me which readings change and which one stays the same.
Anything that is calculated based on different inputs is subject to possible errors That is why they use a constant elevation for said venue and correct to sea level.
You want to see your da meter be off come to south Florida and I will run my car with -out nitrous but with ice water in my reservoir flowing through the ic and see how off your da is, yes using the 1/2 correction for supercharged engines. I will pay all of your expenses to and from if I'm wrong.
What don't you understand about taking a fixed track elevation and correcting for sea level.
Take great Great Bend, Kansas the average city elevation is 1849 ft the nhra uses 1900 ft which is probably the elevation that would be displayed on a GPS at the track and then corrects for sea level. The only way the elevation can change is by earth quake it is not dependent on the weather. The da takes the weather into account which the nhra does not care about and you want to know why because everyone racing at said track is affected by the weather. At different times of the day the weather(DA) will be better or worse but the elevation will remain constant and is the only thing they feel has to be corrected to level the playing field from venue to venue.
Moroso is 21 ft or so above sea level yet with a da calculator you can see numbers as high as 3000 ft, why does the nhra not list moroso as an altitude facility or Gainesville, Florida which can also have Da's in the 3000's, Two tracks that I have personally raced at with those da's. The answer is simple the track elevation does not warrant it and that is all the nhra cares about.
The nhra recently raised the minimum required elevation to be considered an altitude facility to 1700ft.
Go to the beach on a very hot summer day and take a da meter and see what it tells you and then compare that to a gps reading and see the difference.
One is true altitude the other is calculated altitude. Take gps and da readings in the morning at noon and late at night and tell me which readings change and which one stays the same.
Anything that is calculated based on different inputs is subject to possible errors That is why they use a constant elevation for said venue and correct to sea level.
You want to see your da meter be off come to south Florida and I will run my car with -out nitrous but with ice water in my reservoir flowing through the ic and see how off your da is, yes using the 1/2 correction for supercharged engines. I will pay all of your expenses to and from if I'm wrong.
I agree with everything you wrote.
I understand the correction table in use at NHRA, it is actually tracks at 1600 ft not 1700 ft ,this was changed in 2002.(from 1200)
Its very simple, the variance is small and it matters not, no corrected time will ever win a race or earn you any respect, it is a useful tool if used alongside many other data sets. You must have a baseline, you can then try new things. For me it is much more necessary to correct. Your car would be effected by .3 vs my car losing near .6. So your car at altitude would likely be nearly 1 second faster in a bad air day. Bad air effects this high compression engine drastically, ask the Z06 guys, they also suffer. A Z06 same car Ranger drives runs 12.9-13.6 @ LACR and they are pro series drivers.
1. N/A motor
2. Very little real world data on the 63 motor
3. I have 500 plus runs at an NHRA altitude track (LACR)RIP and need to compare those runs to the other CLS 63 running, oh wait I am the only car running?
Any car running at sea level in extreme heat should note DA regardless of the table used by NHRA, the more information on the slip the better. Correction is only for my info, if I am off I will learn the hard way. I believe at this point I have a good baseline being established.
Last edited by juicee63; 09-08-2007 at 11:22 PM.
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Enzom, why are you and Venom not on the MIR track rental list? You guys are close enuff that you should sign up. Sleepy and a bunch of other NY'ers are coming down. You guys should try to make it down, it should be a blast.
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
No your Vette will be very similar to my 63.. It will slow badly in high heat, but since you are sea level should never see too bad of a Density altitude.
SIK car , I almost got one last week..
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Ohhhhhh.Ok,how about this one.2 identical stock cars,but ones running very rich and the other is close to perfect.Now how do you adjust their DA's? Which car would benefit more from the DA correction or would they be equal? If they actuall ran in the better calculated DA's conditions.
Man I get no Love form my LA brother,
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OMG MY DRAMS HAVE COME TRUE.. I ILL BE AT EVERYONE OF THOSE!!!!!!!
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I bought it Wednesday and I had planned to take it to the track on Friday. It didn't happen but yeah, I'm beat'n the he!! out of it right out of the box.Look forward to seeing you at MIR next month.
#124
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I hate to point this out but it is valid in this discussion and shows how accurate the calculator is
http://www.dragtimes.com/2005-Merced...ecs-11697.html
Here is one of your sub 12 second runs. It shows a 4 minute difference as to the weather input and lists the exact same barometric and temp as the slip. Using your slip as an example which of your two runs was better to you? Looks like whats on the slip holds true regardless of an adjustment for negative DA. Your actual fastest run was you best corrected time as well. Once again for information only, your car is VERY FAST and likely can run 12 seconds all day long but going sub 12 is going to take a negative DA, or a 1.6 60ft, or a mod, weight reduction. Great runs and you are a truly consistant runner. BTW your times are even less adjusted than listed but the trend is the same as DA goes more negative your car gets FASTER. It effects your car to a lessor degree so this calc would require a bit more work. You would need multiply the DA by .50 to get a true # for a SC engine. Your actual and corrected times are closer than what is presented below. This was just to show the accuracy of input and what info you could gain by doing this. Obviously just noting the -1000 ft would tell people your run was aided by atmosphere, that would be enough. Your actual corrected time is 11.915@117.5 WOW. My car at this DA may hit 12.1 or so
The closest weather results for 03/31/2007 at 09:59 am
Time recorded 9:55 AM
Temperature °F 48.2
Dew Point °F 19.4
Altimeter Setting 30.27 Inches Mercury
Absolute Pressure: 30.19 Inches
Density Altitude: -959 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.892 (sec) @ 117.72.22 (MPH)
Corrected ET to Sea Level:
12.012 (sec) @ 116.506 (MPH)
The closest weather results for 03/31/2007 at 09:07 am
Time recorded 9:15 AM
Temperature °F 46.4
Dew Point °F 21.2
Altimeter Setting 30.25 Inches Mercury
Absolute Pressure: 30.17 Inches
Density Altitude: -1054.7 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.850 (sec) @ 118.17 (MPH)
Corrected ET to Sea Level:
11.981 (sec) @ 116.83 (MPH)
This is where the correction table the NHRA table is derived RFLOW
Standard Atmospheric Conditions Altitude
(feet) Pressure
(in. Hg) Temp.
(F°) Density
(%)
sealevel 29.92 59.0 100
2,000 27.82 51.9 94.3
4,000 25.84 44.7 88.8
6,000 23.98 37.6 83.6
8,000 22.22 30.5 78.6
10,000 20.57 23.3 73.8
12,000 19.02 16.2 69.3
14,000 17.57 9.1 65.0
16,000 16.21 1.9 60.9
http://www.dragtimes.com/2005-Merced...ecs-11697.html
Here is one of your sub 12 second runs. It shows a 4 minute difference as to the weather input and lists the exact same barometric and temp as the slip. Using your slip as an example which of your two runs was better to you? Looks like whats on the slip holds true regardless of an adjustment for negative DA. Your actual fastest run was you best corrected time as well. Once again for information only, your car is VERY FAST and likely can run 12 seconds all day long but going sub 12 is going to take a negative DA, or a 1.6 60ft, or a mod, weight reduction. Great runs and you are a truly consistant runner. BTW your times are even less adjusted than listed but the trend is the same as DA goes more negative your car gets FASTER. It effects your car to a lessor degree so this calc would require a bit more work. You would need multiply the DA by .50 to get a true # for a SC engine. Your actual and corrected times are closer than what is presented below. This was just to show the accuracy of input and what info you could gain by doing this. Obviously just noting the -1000 ft would tell people your run was aided by atmosphere, that would be enough. Your actual corrected time is 11.915@117.5 WOW. My car at this DA may hit 12.1 or so
The closest weather results for 03/31/2007 at 09:59 am
Time recorded 9:55 AM
Temperature °F 48.2
Dew Point °F 19.4
Altimeter Setting 30.27 Inches Mercury
Absolute Pressure: 30.19 Inches
Density Altitude: -959 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.892 (sec) @ 117.72.22 (MPH)
Corrected ET to Sea Level:
12.012 (sec) @ 116.506 (MPH)
The closest weather results for 03/31/2007 at 09:07 am
Time recorded 9:15 AM
Temperature °F 46.4
Dew Point °F 21.2
Altimeter Setting 30.25 Inches Mercury
Absolute Pressure: 30.17 Inches
Density Altitude: -1054.7 feet
Track Elelvation: 86 feet
UnCorrected ET:
11.850 (sec) @ 118.17 (MPH)
Corrected ET to Sea Level:
11.981 (sec) @ 116.83 (MPH)
This is where the correction table the NHRA table is derived RFLOW
Standard Atmospheric Conditions Altitude
(feet) Pressure
(in. Hg) Temp.
(F°) Density
(%)
sealevel 29.92 59.0 100
2,000 27.82 51.9 94.3
4,000 25.84 44.7 88.8
6,000 23.98 37.6 83.6
8,000 22.22 30.5 78.6
10,000 20.57 23.3 73.8
12,000 19.02 16.2 69.3
14,000 17.57 9.1 65.0
16,000 16.21 1.9 60.9
You need to be more careful about checking your facts -
I ran 11.9's all day long at Atco with a BEST DA of positve 778 feet. And it wasn't on 1.6 60' times, nor did I remove weight. So you are dead wrong there. (Can you admit that much?)
http://www.dragtimes.com/2005-Merced...ecs-10571.html
But I guess if your calculator tells me that it was not possible for me to run 11.901, 11.904 etc. with a DA of plus 778, I will call the Atco track and tell them that they need to check their equipment.
Key here is I ACTUALLY ran those runs. So it isn't what a calculator says I should have run - but what I ran.
I do not recall the DA at E-town that day (3/31), but it was definitely NOT minus 1000 ft. I remember hearing that it was plus 200 ft., but I have e-mails out to two of my friends that were at the Corvette Challenge that day for an answer.
If I come back and tell you that they have confirmed that it was plus 200 ft., will you start to realize that your calculator, and/or your method of collecting data from places other than the track, yield incorrect results? Or are you going to continue to insist that I am wrong?
EDIT - Out of curiosity, what do your off-track sources tell you the weather was when I made my runs at Atco? How far off of 778 ft. is it? Wouldn't that be a fair way of comparing the extent of the accuracy/inaccuracy of your date-collection methods?
Last edited by enzom; 09-09-2007 at 10:37 AM.
#125
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Enzom, why are you and Venom not on the MIR track rental list? You guys are close enuff that you should sign up. Sleepy and a bunch of other NY'ers are coming down. You guys should try to make it down, it should be a blast.
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
Juicee, keep the faith my brother. I can't say that I agree with you but you have stuck to your guns. You guys are way over my head and I'm not even going to try and pretend I know what I'm talking about but I do have a question or two. DA makes corrections based on weather correct? Do you think all cars are affected by the weather the same way?
I don't go see my mother-in-law down the shore because the 1.5 hour trip makes me nuts. If I take this trip just to race, I am done for. You guys understand, no?