NHRA ELEVATION CORRECTION FACTORS
One thing that many folks tend to disregard when comparing the quarter-mile performance of their vehicle against that of another is the conditions in which the track testing was performed. Two major factors are the weather conditions (ie. ambient air temperature, humidity, barometric pressure......) and the elevation at which the runs were made. Both of these can be a major factor in the performance of your vehicle because they directly affect the amount of oxygen present in a given amount of air. Hotter, humid air contains less oxygen per part than does cooler dry air. Additionally, the air at higher elevations also contains less oxygen than air at a lower altitude. Because of this, the NHRA has come up with these mathematical conversion factors to allow you to correct your ET and trap speed to sea level for a more accurate comparison. You're on your own above 5500 ft.
|
To convert your time slip ET and MPH to sea level, multiply applicable factor times your ET or MPH. (Example: You ran a 13.8 @ 100 MPH at 5000' elevation track. The correction factors are .9367 and 1.0661 for 5000'. (13.8 * .9367) = 12.93 , (100 * 1.0661) = 106.61 MPH. So the correct time slip would be 12.93 @ 106.61 MPH.)
|
||
|
Altitude above Sea Level (Feet) |
Elapsed Time Factor (ET) |
Trap Speed Factor (MPH) |
|
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 |