How fast is your car?
How fast is your friends car on the other side of the country?
The NHRA uses a correction factor to compensate for altitude for stock/super
stock classes.
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.
Race City has an altitude of around 3500 feet.
NHRA Altitude corrected index in Calgary is S/ST = 11.27, S/G = 10.24, S/C =
9.20
Comp, Super Gas, Super Comp and Super Street conversion
Convert to Sea Level ET- .9669 MPH - 1.0315 |
Convert to Altitude ET- 1.0342 MPH - .9694 |
Stock, SuperStock conversion
Convert to Sea Level |
Convert to Altitude ET - 1.0444 MPH - .9568 |
Altitude above Sea Level (in feet) | Elapsed Time Factor | MPH Factor |
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 |