Has anybody calculated ET's compared to track temp?

[06vistabluegt]

I've been logging my runs down the track for a couple years now hoping to be able to predict my ET's if for some reason I didn't get a time trial or weather made a big change between time trials and elims. My data seemed to not show a big difference in et based on DA. I did see a difference if a major swing in DA happened but not the a huge difference. I thought humidity was really affecting times but I didn't see that in my data either. This year I decided to start tracking track temp as well. So far it seems the biggest thing to affect my ET's is track temp. The lower the faster. I've had runs at 3000' be as much as .2 different. Track temp seemed to be the big difference.
Anyone else seeing this as well?

 

[Diabolical!]

I've never done the calculations, but it's hardly worth it for me to even go to the track this time of year. With temperatures in the upper 90's and humidity near 100%, only my first run of the night is worth driving to the track for, and even that is a few tenths slower than my winter runs. Gulf coast summers suck for drag racing.

 

[06vistabluegt]

I've never done the calculations, but it's hardly worth it for me to even go to the track this time of year. With temperatures in the upper 90's and humidity near 100%, only my first run of the night is worth driving to the track for, and even that is a few tenths slower than my winter runs. Gulf coast summers suck for drag racing.

I'm a bracket racer so my only concern with times is consistency along with staying within class rules. I ran this past Friday night for the first time this season. I usually race on SAturdays and race during the hottest part of the day. Times trials start at 7pm and elims start at 11pm. My First time trial I ran a 13.19 with the track temp at 115. By the end of the night the track temp had fallen to 80. My times dropped to 13.13 (3 of them in a row) but DA stayed around 2700, never varying more than 100ft between runs.
Just thought this was interesting.

 

[Born To Run]

Logging,weather vs performance

I've been logging my runs down the track for a couple years now hoping to be able to predict my ET's if for some reason I didn't get a time trial or weather made a big change between time trials and elims. My data seemed to not show a big difference in et based on DA. I did see a difference if a major swing in DA happened but not the a huge difference. I thought humidity was really affecting times but I didn't see that in my data either. This year I decided to start tracking track temp as well. So far it seems the biggest thing to affect my ET's is track temp. The lower the faster. I've had runs at 3000' be as much as .2 different. Track temp seemed to be the big difference.
Anyone else seeing this as well?

I log the weather after every pass & it is vital to do so if racing any kind of bracket or handicapped style of racing.I race in the NMRA & almost everyone logs weather.I log temp,hum,bar,DA corrected & gpp(grains per pound)wind speed & direction,sunny,partly sunny,overcast,dark etc.I also log front & rear tire pressure & ballast loaded.
At my home track last weekend i only had 1 qualifier on Sunday & i predicted my et to be 11.25 based on weather data from previous logs,my first & only qualifier i ran 11.255.
Track temp should be measured if you are having traction issues in the 1st 60',but if your 60's are all the same don't log it or fight it.
I am supercharged & the weather effects FI more so than NA cars.
Track temp has no bearing on the performance of the engine or et,unless the track temp exceeds 115 then VHT & rosin do not adhere to surface,but make matters worse,the best track temp for prep is 95-105F,after 115 F dragging the track is the best you can hope for is to cover up the bald spots of concrete shinning through on the starting line.
So if the track temp is lower then the ambient temp is lower & usually DA moves lower & wind dies out,resulting in a quicker et.This will occur when the sun sets beyond dusk.
Buy yourself a Kestral weather station & start logging & you will be able to predict the effects & et of your race.Most of my NMRA races are won or lost on 1/100th of a second,over or under are dials.
Good luck.

 

[SRTthis]

we measure track temp but we do it to see what kind of power we can throw to it and how tight to keep the front end.

 

[Mishri]

weather plays a significant role in my ETs. I've seen up to .5 difference. one of the biggest factors is barometric pressure. humidity, not so much, but extremes can make a .1 maybe even .2 difference between 10% to 99%. and air temp does too.. usually im looking at 60-100 degrees at the track.