Re: Weather Conditions ET effect.

[bwallace]

I was wondering how the weather effects other TR's at the track. I went out last friday and made 3 passes and was at least a half a second slower that usual. The temp was in the mid 80's with 90% humidity. My best time in my TR is 13.30 60 degree temp and low humidity. Friday 13.86.

 

[JoyOf6]

Keep detailed records of weather conditions along with ET slip data, and and evaluate how the combo behaves. I happen to use a weather station that spits out barometer, temperature, humidity, etc., and it calculates density altitude from these parameters. Then compare runs and see how they vary with density altitude (or whatever specific measurements you can make), taking into account any differences in 60', traction, wind, sign of the zodiac, etc. in these comparisons.

I think my data come out to about 0.05-0.07 sec per 1000' d.a. for a 9-sec car... been broken all year so it's not fresh in my mind. I would imagine proportionally (?) lesser and greater effects on ET would be observed with faster and slower cars, respectively.

Art

 

[turbofrank]

high humidity=slower et
low barometer <30. =slower et
high temp >90 =slower et

 

[bwallace]

Thanks for the information!!! I was really wondering if a .5 second drop in ET was unusual? Once cooler dryer weather comes around I will see what happens.

 

[don86T]

Bwallace,

If you were at Capitol Friday 8/8 the biggest problem was the track. My 60' times were almost .2 off and my 1/4 ET was about .3 slower than 2 weeks before.

I hope I can pick up a few tenths when the weather cools

Don