I ran a 13.57 my first time at the track. The elevation is 1,400 feet. Does this affect 1/4 mile times? Since my first time out, it has been 75 degree plus days and never have good conditions and have been running 13.6 to 13.7s. Does anyone know of a place to find this out? Thanks!

 

Generally speaking, higher elevation has it's ups and downs. Usually, the higher you go, the cooler the air is...and LS1's love cooler air. Unfortunately, the higher you go, the thinner the air is...which means less oxygen & poorer performance. At 1400 ft, I don't know if you'll notice much of a change in the performance of the car unless it's heavily modified.

 

I know the LS1's love the cooler air. I went to the track a few weekends ago and the temps at the track were registering 106. I was hitting mid to high 14's and as the night cooled a little to the upper 80's the time dropped to 13.9. Last week was in upper 70's and was hitting 13.6. So it makes a big difference with temperature.

 

It's not just absolute altitude, it's density altitude ... the combined impact of temp, pressure and dew point; plus the absolute altitude.

It's not the cooler air that our cars like, it's the richer O2 content of cooler air ... cooler air will yield a lower D/A than warmer air ...

If you were at 1400 feet at 75* your D/A could have been in excess of 2400 feet ... compared to a sea level or 0 D/A, it is probably in the range of 4-5 tenths difference ...

 

I ran my times at 1300ft elevation..but I don't list that, and I don't correct my ETs...

and I don't think I would have done much better close to sea level. Besides..apples to apples, right? How many people around here run at a dragstrip close to sea level? Most everyone has to deal with this. If you're worried about comparing your ET to others on this board...it all evens out.

 

I agree with you, correcting your ETs for you sig is bush ... But if you are comparing you need to take all the factors into consideration, not just elevation ... depending upon time of year D/A at my local track ... 80 foot elevation ... can vary from -300 feet to over 2100 feet.

Do a google search on NHRA altitude correction factor and play around with them, you'll be suprised how much of an impact they make. Then do search on density altitude calculators, go to weatherunderground.com, get the historical weather info and you can find out the D/A when you made your runs and see for yourself the difference in your runs from one date to another ...

Then use the correction factor to level them out .. it's really the only way you can really assess the impact of your mods at the track ...