Density Altitude Calculator

[grazi]

I was playing with the density altitude calculator on dragtimes.com. Maybe some of the drag racing guys can help explain it to me. I ran my car a couple months ago and ran 13.65 @ 100.8 mph with a DA of 1484 --which I dont know if thats good or not--.. I changed the settings to be 32 degree day, 30.00 barometric pressure and 10 % humidity which gave it something like a -1500 DA.. I re calculated my 1/4 time with that DA it made it run almost a 14.0....Wouldnt a lower DA (lower temp, higher BP and lower RH) make the car run faster?
Just trying to absorb some knowldege

[donnj]

13.65 @ 100.8 mph with a DA of 1484
1500 DA made it run almost a 14.0....

???

[grazi]

-1500 (negative fifteen hundred)

[grazi]

-1595 to be exact changed it to a 13.89

[98tadriver]

from what ive read, 1000' of DA change =.13 second

from personal experiences, it seems like every 800-900' is equal to a tenth

assuming everything on the car is the same and you drove it exactly the same as last time, you'd be looking at .3 to .35 sec reduction in ET

[sweetbmxrider]

You goofed somewhere. Density Altitude basically means where in elevation is the car racing at compared to sea level. So if the track is 100ft above sea level but the da is +1000 feet, its like you are racing on a large hill. If the da is -1500, its like you are in a submarine. Negative da = faster et's and mph's