How fast is your car?
How fast is your friends car on the other side of the country?
Many automotive tests also use this factor when giving 1/4 miles stats. This way you could run a car at sea level and have an identical car running at 6000 feet. The car running at 6000 feet will be considerably slower but by using the conversion factor you would see they run the same. Just because someone says they have a car that run's low 13's doesn't mean much against yours unless they are on an equal playing field.
If you really want an accurate conversion, then do your calculations with density altitude. A car running on a high density altitude at sea level will be slower than than same car running on a low density altitude at 3000 feet elevation.
To convert your Quarter Mile ET and MPH to sea level times, multiply applicable factor times your ET or MPH. Altitude above Sea Level (in feet)
First Column is altitude above Sea Level in Feet
Second Column is what you multiply your 1/4 mile ET by
Third Column is what you multiply your MPH by
1200 .9874 1.0129
1300 .9861 1.0143
1400 .9848 1.0157
1500 .9835 1.0171
1600 .9822 1.0185
1700 .9809 1.0199
1800 .9796 1.0213
1900 .9783 1.0227
2000 .9770 1.0241
2100 .9757 1.0255
2200 .9744 1.0269
2300 .9731 1.0283
2400 .9718 1.0297
2500 .9705 1.0311
2600 .9692 1.0325
2700 .9679 1.0339
2800 .9666 1.0353
2900 .9653 1.0367
3000 .9640 1.0381
3100 .9627 1.0395
3200 .9614 1.0409
3300 .9601 1.0423
3400 .9588 1.0437
3500 .9575 1.0451
3600 .9562 1.0465
3700 .9549 1.0479
3800 .9536 1.0493
3900 .9523 1.0507
4000 .9510 1.0521
4100 .9497 1.0535
4200 .9484 1.0549
4300 .9471 1.0563
4400 .9458 1.0577
4500 .9445 1.0591
4600 .9432 1.0605
4700 .9419 1.0619
4800 .9406 1.0633
4900 .9393 1.0647
5000 .9380 1.0661
5100 .9367 1.0675
5200 .9354 1.0689
5300 .9341 1.0703
5400 .9328 1.0717
5500 .9315 1.0731
5600 .9302 1.0745
5700 .9289 1.0759
5800 .9276 1.0773
5900 .9263 1.0787
6000 .9250 1.0801
Now that you see all this I went to the track last friday...will post slips if you want me to and I ran a 15.436 @ 93.4 mph
There was a guy there who was measuring the Density Altitude and it was at exactly 8000 ft above sea level and 84.5 degrees
if you notice on the chart above for every 100 ft above sea level you subtract .0013 from the number you multiply your ET by to get the correction factor for sea level
Now we find out that at 8000 ft. we need to multiply our ET by 0.899 (6000 ft = .9250- (20)(.0013) for 8000 feet
15.436 X 0.899 = 13.87
Now if I remember correctly I said that I ran a 13.89 at sea level on a 55 degree night....
Do you still not believe me???? If so I will post my slips
information came from this site:
http://www.hardtail.com/techtips/altitude.html