juicee63

I have contacted the SAE and submitted the NHRA table for review by the SAE.

I have asked whether the adjustment factor is derived from Pressure altitude or Geometric Altitude

I also asked what the accuracy was for the Density altitude calculation and how reliable it would be in predicting 1/4 mile runs at the SAE standard Pressure of ZERO .


I know after reviewing all my slips from Los Angeles County Raceway(Palmdale) listed at 2700 feet, the altitude correction is not as accurate as Da calculation.

This predicted my best run at sea level would be a 12.68@108, My trap speed is always 109-113.5, and the ET has already been bested by 7/100ths.

Remember this is predicting a run at STANDARD PRESSURE ZERO FEET. My best time was at appx 1000 ft above sea level based on Pressure Altitude Calculation. when using DA, a 12.36@115 could be obtained at ZERO feet. Since I have yet to run at zero feet I can only say at this point neither method is exact but I speculate the NHRA table is derived in the EXACT SAME MANNER as the DA calculation

I will report back what SAE determines and any insight they can lend to this debate

juicee63

Nope I am not like you.

I want solid , reliable data that will allow me to choose the most accurate dial in.

I want a DRIVERS race.

A 12.4 time @ 114 at NED vs a 12.4 @ 114 at Palmdale?

LOL the NED car would be SLAUGHTERED, no contest, this is why we correct the slip run at ALTITUDE.

Your arguments for not correcting are fool hardy

Ted Baldwin

..........When Micheal Johnson and Carl Lewis broke the world records in the 100meters and 200 meter races, did the IOC use a calculator or a stopwatch to figure out if their times were indeed the fastest before awarding them the records?

..........When osafa powel became the worlds latest fastes man, how was that determined? With a calculator?

.......Or do you think temp and altitude only affects cars?

Ted

enzom

This is getting twisted around. If you are talking about applying DA factors to figure out your own dial-in for bracket-racing at track A while you're running at track A, that's one thing. You have data from track A and know that with a DA of 700 ft. and average track prep - you can run X. You can therefore ESTIMATE how your car might run with the same track prep, same wind, etc. at a DA of 2000.

But what you are advocating is collecting data from an airport miles away from a track to try to tell someone precisely what their times would have been had they magically showed up at a sea level track, with the same track prep, under different weather conditions.

They are two completely different things. It is the second thing that people have an issue with. Let's keep the issue in focus.

Anyway - Juicee - as hard as you are trying, and I give you tons and tons of credit - you are not going to convince any of us that believe otherwise that "correcting" someone's time using weather data taken from miles away is an accurate way to standardize times at different tracks. Saying "I ran a 12.8 @ 114 with a DA of 2800 ft (measured AT THE TRACK) on an 80 degree day (measured AT THE TRACK)" tells us all that the car is capable of much more. That says enough. But saying "I ran a corrected 12.223 @ 118.77, which ranks me 2nd" just gives it too much credibility, IMO.

By the same token, it is obvious that you are not going to accept the fact that weather data taken from miles away at different time can never ever be identical to replicate actual conditions at the track - which makes the calculation inherently and necessarily flawed. Garbage in; garbage out.

So, at this point, there is nothing further to discuss.

Get your AZZ to a decent track with decent weather and get an actual timeslip that represents what your car does run in ideal conditions. I know you will do that as soon as it cools down.

edit - AND I AM PULLING FOR YOU

rflow306

Juicee for the last time you are not correcting to altitude you are correcting to Density Altitude. If you want to keep correcting that is fine by me but don't give incorrect information.Definition of altitude: Altitude is the elevation of an object from a known level or datum (plural: data). Common data are mean sea level and the surface of the WGS-84 geoid


Density altitude is not altitude it is a prediction based on readings that are constantly changing. You could have a million dollars in weather equipment and the correction would still not be fact, why because it is nothing but speculation .What if I were at sea level? What If I were at sea level in 90 degree weather, what if I were at sea level in 50 degree weather.

My suggestion to you and it will be my last is forget about the what if and live in the what is. Forget about the guess work and run your car at a sea level track plain and simple.

JAYCL600

just admit it juicee the E55 is faster

teasin you man, had to break the ice

juicee63

The correction is solely to speculate dial and handicap matchup with cars running at sea level or even cars running at Altitude on a good air day vs a bad air day.

I get it , and you and Rflow , keep saying the same things as do I.

I will attempt to change the language, and not use "I ran " or even "will run"

This is simply to predict by using as RFLOW points out ALL AVAILABLE DATA,

And yes Enzom I use it to pick a dial at a specific reading on a DA meter.

I do believe the NHRA table is derived from a known "pressure altitude reading" but it matters not as it seems you guys are concerned more about perception of the predicted run as if it actually happened, LOL. Had I been doing this I would have just posted the corrected run and gave no mention of the actual times :-).

We have great data on the 63, it is a very very very consistant car so it will be easy as you can seee by recent runs by rookies to get an experienced driver in good air to dip down a bit further.

your ACTUAL stock times are likely as fast as a stock 55 will EVER GO , for this I give you respect and of course will listen to any suggestions you have, you too RFLOW as you are an intelligent and thoughtful.

Jay, your my teacher, you got me hooked and I just wanna get the max out of my car. Man I am soooooo excited for the 10 lb battery and the CCW's..

juicee63

You keep bringing up runners,

I have pointed out to you 100 times

THE IOC does take into account , ALTITUDE, and ATMOSPHERE.

world records are dotted with asterik after asterik noting condition that aided the world record times.

There are thousands of studies on the effects of atmosphere on athletes, so your example simple solidifies my position.

The only valid points in this thread are

1. DA correction is not 100% accurate, it is dependant on the accuracy of its INPUTS.
2.Listing corrected times as if you ran or are going to run them is not acceptable

juicee63

Thanks man...

juicee63

http://forums.corvetteforum.com/poll...pollid=1503408

looks like they are getting smarter over there!!

MB_Forever

Although data collected from an airport 5 miles away are not identical to data collected from the track, it is pretty darn close. In fact, I think data collected from the track would benefit Juicee's time, not hurt it. So far, the only real data we have is the ones that Juicee provided us from LACR compared to Sacramento, and this data shows Juicee's calculator to be very accurate.

For example, Juicee's calculator told us that his runs @ LACR (13.3 to 13.7 seconds) would be 12.5 to 12.8 seconds at sea level track. And that is exactly what he ran at Sacramento. This is hard and concrete evidence on how accurate the calculator essentially is.

Juicee, I think the best way to actually prove whether the calculator is wrong or not is to run a few runs in bad DA (at LACR) right before you go to Speedworld, then correct these times. And then after you run at Speedworld, compare the corrected LACR runs to actual Speedworld runs and you will get an idea of how accurate the calculator really is.

This is very interesting......

Bluemax

I finally had the Division Seven director from the NHRA on the phone about some rule changes for S\C. And asked him for the correction table for all door car classes and here it is http://nhra.com/tech_specs/altitude.html. Hope this clears up some of the questions about Correcting times.

Ted Baldwin

.........of course atmospheric conditions affect athletes even more than it does cars. Despite this, there is no single calculated time listed athletes. Is the IOC just stupid? Here is a list of the fastest times ever run in the 100 meters dash. Notice that these times were all run by different people at different times and different place and different DA's. Notice that The current world record is 9.85secs and the previous one was 9.87secs. Both races run by different people at different places an different DA's.

..............Is it your argument that the new world record of 9.85secs is calculated and not an actual time taken directly from the clock? With such a small marging between 9.87 and 9.85, should the IOC use DA info to calculate who the world record actually belongs to?

http://www.factmonster.com/ipka/A0106405.html

...........No, the problem is not solely the accuracy of the input data. The point is that the calculated data at best represents potential, while the actual timeslip represents achievement. You see, the rest of the world rewards achievement while recognizing potential. The world's tallest man is the man who actually measures the tallest with a ruler, not the one with the potential to grow the tallest.

.....The guy with the biggest ***** is actually the one who's ***** is the largest, not the guy who claimed his ***** shrunk because of a cold shower and wants to use a calculator to determine how big his ***** is by factoring-in the temp and altitude of the shower stall.

Ted

rflow306

Ted you are wasting your time, Juiecee has put so much passion and hard work in his correction method that it has become a sort of fanaticism which clearly has had a profound effect on his better judgement.

Jrocket

Please leave me out of these arguements!

rflow306

You are from the west coast which is correction central, so you must be the second guy.

Jrocket

So true.Ya caught me with my pants down on that one,no pun intended of course!

juicee63

Ted your input on this is entertaining.

You use analogy that in non analagous, you state the obvious , none of which is applicable to this thread.

and RFLOW, Density Altitude IS ALTITUDE LOL... Comon man read read read , how do you think SEA LEVEL IS CALCULATED.

I think MBFOREVER is spot on and I challenge ALL OF you to show me examples of the calculators inaccuracy. I only have examples of its USEFULNESS.

Funny thing here is nobody on the thread claimed they ran the "adjusted" time. Car would run X at Y altitude is all that is being stated, we could go the other way as well. You folks could take your Negative DA runs and calculate them to a 5500 ft DA so you would have an idea of what your car may run at ALTITUDE.

Is there ZERO statistical and analytical backround in this forum? At the very least in order to compare we MUST CORRECT ALL THE TIMES TO THE SAME STANDARD AIR PRESSURE.
You guys running nos , LOL, no need to even talk about this.

I have spoken to the person at SAE who crafted the equation for altitude and the correction factor is derived from SAE pressure, THE DENSITY OF A COLUMN OF AIR AT A KNOWN ALTITUDE.

all we are doing is a DA calc and aligning it to the closest KNOW ALTITUDE for that air pressure reading.

everything from 1200-5500 IS VERY VERY VERY ACCURATE.

The more I dive in the more I know you guys are not being objective, especially Ted who has added nothing at all to the discussion. Open your minds folks , drink the cool aid, just because you failed to have a concise and complete data pool with the 55 , do not attack the 63 for establishing a baseline.

I think I have predicted the ability of the 63 with incredible accuracy

I have helped 3 members(soon a 4th) here get to 12.4 when they assumed 12.7 was all they could achieve, I gave em everything I had learned and guess what? The little sixty threes did it. So now I know this fall we WILL SEE a 12.2-12.3 run with a 115-117 trap, I may even do it in the CLS at SACRAMENTO, but that would ONLY HAPPEN AFTER REDUCING weight a tad......I know because I correct after I run, had I listened to you guys on this I would have sold my car after the first 14.7 run at Palmdale. You folks should be thankful for your negative air density rather than attacking folks with bad air that correct for comparison. I know what I would run at nearly every altitude because I corrected my times. I listed ALL OF MY SLIPS ACTUAL SLIPS and simply noted the DA in comments. I feel this is helpful to even people that hate correction

Jrocket

From the top of the water?

juicee63

http://www.iaaf.org/statistics/index.html

Since you LOVE RUNNING examples and like I said you further SOLIDIFY what I am doing by the use of human s

http://scarletknights.com/track-wome.../met07-out.pdf

Patrick Johnson
Australians got very interested in the 100 m Sprint in the week ending Sat 10th May 2003, when Patrick Johnson ran an Australian record of 9.93 secs (with 1.3 m/s wind assistance) on 6th May at Mito, Japan, and followed up on 10th with a 10.05 sec run (-0.3 m/s wind) in coming second to Tim Montgomery at Osaka, Japan.

What will it take for Montgomery to match his world record - and someone like Johnson from Torres-Strait Islander and Irish stock beat it ? See discussion below about wind effects for some clues (Jonas Mureika's wind and altitude correction calculator suggests Johnson's two May efforts were equivalent to corrected times of 10.02 (Mito) and 10.03 (Osaka)), but to really know the answer to who is the faster man you might have to look at 10 m splits for their races...

The Comparing 100 m Sprinting - Wind & Altitude Correction page shows how correction for wind and altitude might affect rankings, and can also be useful in eliminating some of the variability in trends in average top performances.

http://condellpark.com/kd/compare100m.htm


Ted you may actually want to think about what you type, seems your OLYMPIC running tirade only strengthens argument FOR CORRECTING

Table 1 - Wind & Altitude Adjusted Sub 9.90 100m Rankings

Corrected
Time
Name Venue Date Raw
time wind
9.80 Maurice Greene Athêna 1999-06-16 9.79 0.1
9.81 Maurice Greene Sevilla 1999-08-22 9.8 0.2
9.83 Maurice Greene Edmonton 2001-08-05 9.82 -0.2
9.84 Ato Boldon Athêna 1998-06-17 9.86 -0.4
9.85 Maurice Greene Berlin 2000-09-01 9.86 -0.2
9.85 Bruny Surin Sevilla 1999-08-22 9.84 0.2
9.85 Johnson Ben Seoul 1988-09-24 9.79 1.1
9.85 Maurice Greene Sydney 2000-09-23 9.87 -0.3
9.86 Frank Fredericks Lausanne 1996-07-03 9.86 -0.4
9.86 Tim Montgomery Edmonton 2001-08-05 9.85 -0.2
9.87 Ato Boldon Athêna 1999-06-16 9.86 0.1
9.88 Maurice Greene Athêna 1997-08-03 9.86 0.2
9.88 Ato Boldon Kuala Lumpur 1998-09-17 9.88 -0.1
9.89 Tim Montgomery Paris 2002-09-14 9.78 2
9.89 Maurice Greene Osaka 2000-05-13 9.91 -0.4
9.89 Johnson Ben Seoul 1987-08-30 9.83 1
9.89 Donovan Bailey Atlanta 1996-07-27 9.84 0.7
9.89 Donovan Bailey Abbotsford 1997-07-19 10.03 -2.1
9.89 Leroy Burrell Barcelona 1992-08-01 9.97 -1.3
9.89 Calvin Smith Bruxelles 1983-08-26 10.04 -2.2

So, Greene has gone sub-9.90 seven times, followed by Boldon (three),
Montgomery


After correcting for wind-and-alititude:

Maurice Greene's 99 world records would stand. Every other world record had wind assistance that ranks it inferior to the best wind-corrected run of the time.
Burrell's 94 run would have been a "wind-and-altitude" corrected world record.
Fredericks in 96 and Ato Boldon in 98 would also have rated as world records.
Calvin Smith's 3rd Jul 83 altitude wind assisted 9.93 world record would not stand, but his 10.04 into 2.2 m headwind on 25th Aug 83 (at Bruxelles) would rate as a record (corrected to 9.90)
Viktor Bryzgin's 1986 run of 10.03 secs into a 2.5m headwind would have been a world record.
Until 2004, some statisticians had categorized the wind reading for this run as doubtful. But the IAAF records list published Dec 2003 has it as legal. It looks no more or less suspicious than Smith's run
Leroy Burrell's 91, Carl Lewis' 91 and Carl Lewis '88 world records would not stand
Tim Montgomery's 2002 world record would not make the grade.

juicee63

http://forums.corvetteforum.com/show...post1561830959

even the Vette guys are coming around

WOOOHOOOOOOOO we are winning the poll

Ranger does some GREAT DA analysis in his thread, he uses DA just does not correct the time.

So can we all at least agree DA is IMPORTANT to note?
I promise to not say "corrected I ran an 11.997@130" I will simply note the DA

http://forums.corvetteforum.com/show....php?t=1541575

enzom

I swore that I was done with this but that can't be correct, can it?

The DA AT the track from run to run can vary by HUNDREDS of FEET. In two hours of waiting to run, the DA can vary tremendously. If you are going to perform DA adjustments and carry them out to the hundredth as if you are holding an imaginary time slip in your hand, you need to AT A MINIMUM know the DA that you just ran under.

Let someone play with those calculators and tell us what the difference is between two runs with a 700 ft DA difference.

If someone is touting accuracy - as opposed to what a car could have done at 0 DA - then that person needs to be extremely accurate in assembling their data points. Seems pretty obvious to me. Pretty damn close, which it isn't, is not good enough. And I have, by the way, noted DA's and checked the closest weather stations on the web to compare. More often than not, the measurements off the net yielded a lower DA than what was measured at the track.

Second - Juicee used his track calculator to show what his car could have run at SAC. Did he adjust his run from SAC to see if the adjusted figures were equal? Or does DA only affect cars at LACR? That would show us more about how the calc works, no?

Look - again - it is fun to play with a calculator and say "This car could run 12.4 at a decent track with good air". But to run a 13.2 and then call it a "Corrected 12.412" using estimated and incorrect data is very, very different.

We can debate all day long about why one method works and one doesn't, but there can be no debate whatsover that if the data is not accurate, you cannot claim the resulting calculation to be "correct". Just can't.

For some reason, people keep side stepping this important point as if I have never raised it. Seems to me that if someone wants to defend a position, they need to respond to fundamental challenges.

Even in the Corvette Forum, the poll only says that "DA corrections provide a better indication of what a car "could" run at sea level". Big difference between "could" and "accept this time as an accurate assessment of how quickly I would have/did run."

Now get to a decent track or move.

enzom

YES!! I will agree with you that DA is important to note. It absolutely is. It tells us alot about the run. And nobody is saying it is not important.

So run and note your DA's. Heck, you can even apply the static NHRA correction factors. If the NHRA says you can do it, then who can argue That will bring your LACR times down considerably right there.

And get some sleep, will ya?!!!

Juicee - I do hope you realize that in all of this banter, and even if I think you are dense at times , I still respect what you are trying to do and your commitment to racing. Keep it up.

rflow306

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.
Track elevation 3,700 ft. TNT Fridays: 8 to midnight. Super Street Shootout Series Sat. 9 - midnight. ET Brackets on specific dates only.

Contact Information
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.

wolverine

This is definitely an interesting thread. I would agree with everyone who says that DA is important to note. It will give you some idea of what the posted time MIGHT HAVE BEEN under ideal conditions.

Juice asked for an example of how a DA could give an innacurate result, and I gave an indirect example in my earlier post. Let's say you can exactly calculate the DA, from measurements taken close to the air intake of the car, at the precise time the run is done. I would submit that the DA correction factor will give you overly optimistic times on hot days, and pessimistic times on cold days.

The reason for this is everyone knows that you get a better launch on a hot track than cold. On a very hot day, you'll get a better 60' time than you will if it's 40 degrees out. But this isn't taken into account with the DA correction factor. So if you take the best possible time on a hot day with the best 60' time and apply the correction factor, you'll get a theoretical time that can't really be matched. It would be like you gained the benefit of a great traction in the first 60', then had your horsepower increased for the rest of the run. These things would never happen in the real world. The days your engine is making the most hp will be the worst days for a launch, and vice-versa.

So, even with perfect data, the DA correction factor is not completely accurate.