im racing on a track (airstrip) that is 364 feet above sea level. when does this start to become a factor for 1/4 mile et's ?

Not really until ~ 1000+...Even then I've seen some decent times.

I'm at 7400' everyday at work, and my closest track is 5400'..

What elevation were you at before in the US? If you were close to sea level then at 364 ft you'll see little change. Consider yourself lucky! Even around here they're about 600 ft or so and it's not that bad. Here are some links that'll tell you everything you ever wanted to know (and probably way more lol) about air and density altitude:

http://wahiduddin.net/calc/density_altitude.htm
http://www.aerospaceweb.org/question...e/q0046b.shtml
http://www.coolingzone.com/Guest/New...(Jan%2003).htm

The first one has some online calculators if you look on the left hand side menu.

364' ASL is about the best you can hope for. The tracks I run at are betwen 700 and 900' ASL and you know I do alright

Density altitude is the true measure of how good the atmosphere is for racing on any given day, and it requires some simple calculations to figure out, including atmospheric pressure, temp, dewpoint, and elevation.

Mine is at 165 ft... wouldn't call it a coastal track but almost. If you're under 1000 ft I wouldn't be worried about it hurting your times in any significant way.

The height above sea level that you start to suffer performance problems is 1 foot. Maybe less. lol

But your elevation is fine dude. You shouldn't be more than a tenth slower than the lowest track in the US. But, like Neal said, you have to look at the overall conditions. The air density is very important.

Here's a good calculator that I always use for my logbook:

http://wahiduddin.net/calc/calc_da_rh.htm

If cold enough, you can get a density altitude of way below 500 feet BELOW sea level. This winter in NC, I can get 1200 below sea level DA with only 40 degree weather and 30.0 pressure.

Aaron that's the same link I posted! lol It's a good resource.

Haha Shows you how good I can read. lol

am at like 3 feet above sea level =P

englishtown, raceway park = 60ft. ( I read this off their website)