Just went to the track yesterday and ran a 15.0@91mph. Last time I was there I ran a best of 15.4, with mostly 15.5's @ 85mph. Could this improvement be beacause it was 54 outside? Last time i was at the track it was 80. Only thing I did to the car was take out all the a/c parts, and they werent too heavy.
-later

85 trans am
bone stock LB9
K&N
airfoil
flowmaster muffler

 

85,

From my recollection, the ideal conditions for an internal combustion engine to make power are at 57°F, 35-45% RH, and at sea level or lower (a high barometer of 30.00" Hg or better).

The colder air is more dense, but is not so cold that it doesn't allow good fuel atomization. The moderate relative humidity is low enough not to displace air or fuel molecules in the intake charge, but enough to help combustion chamber cooling and efficient combustion and heat transfer of the combustion gasses. The lower altitude/higher barometer increases air density further, allowing better cylinder charging.

Unfortunately, as temperatures decrease to the point where the engines like it, the tires begin to complain by losing some traction due to hardening of the rubber compounds.

If you were running on a still-warm track with hot tires and a nice, cool engine and air temperature, a half-second drop in ET is not only realistic, but should be expected. The best runs are usually made in the early evenings because of these same factors. Nice way to end the season, dude.

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Later,
Vader
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"Make Me Bad"
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