Ok hope get out what im trying to ask.Is there a rule of thumb or formula for doing your dial ins when the weather changes at the track.Example last nite we ran a 13.941.Temp was 85.1 humidity was 25% dewpoint was 45.3 B press was 30.16 Next run was a 14.255. Temp dropped back to 81.2. humidity was 29.% dewpoint was 45.9 .B pressure was 30.13.> I was calling the wife getting the info for the weather from the track site before we would run< So in less than 90 min of time the humidty changed 4%,temp.3.9 Dewpoint 0.6 BP .3........... We run a 93 TA Stock no tune street tires CAI 160 therm. 60 FT times were 2,120,2.197 Differnce of.077.1/4 times diff of 0.314..Im just finding that dialing in on these cars is alot different than the CARBED Cars .Oh ya would the track temp play into this temp of the pavement < Always thought that was for the air pressure in slicks.

 

Anyone?

 

Are you just testing or bracket racing?

 

Bracket raceing

 

I would not depend on the tracks website or the track for weather info. You can got a weather machine that will give you the DA as well.

Are you on street tires?

Is this street night or money night?

Is your car auto or manual?

Those times seem quite different. Its hard to dial in a car with that much difference in et from run to run.

Get a pair of drag radials
hopefully you have an auto
get your own weather measurments
keep a log book, write down each run and info about each run.
Do Not run your AC
Get your lights down in the .000-.060 range.

also imo I would not do burnouts with street tires or drag radials for bracket racing. I found my car was much more consistant without doing burnouts. The only thing I would do is avoid the water and just kinda stomp it not hitting the brake or anything and sometimes the tire might turn over a little but it just throws of any trash that might be on them. If I did a burnout it would cause traction problems as the night went on because they would get gooey and every rock would stick to them.

also if you are cutting consistant lights now in the .150 range try this:
Always stage your car the same. Shallow as possible. light the first stage light then set your launch RPM (wait for the other car to light there first light too before setting RPM) then inch up until you barely light the second stage light.
Your launch RPM is going to change your vehicle reaction time depending on what RPM you launch at. Try differnt RPMs until you get your RT where you wnat it. Generally the higher the launch RPM the faster the RT until a certain point. There are other things that play a role in VRT as well such as front tire height and tire pressures and engine power and vehicle wieght. So if higher RPM doesn't work you may have to look at other things.

Good luck.

 

As mentioned above, the weather can play a difference, but 7 hundredths difference in your 60 foots between runs is not from the weather. Making consistent passes (stage and shift rpm, engine temp, and hooking) is the first thing to concentrate on. Then start looking at weather. I've bracket raced for 15 years without using a weather station and done fine, but added a weather station to my track tools last year, and it's good to use when you "think" the weather is changing, as it gives a second opinion. I use a Kestral, but there are plenty of good weather stations out there.

Derek

 

Money nite .And we just started about 9 weeks ago keeping everthing logged.And we have a 700R4.This was a first for this car the 13.941.98% of the time were 14.25 to 14.35.Had a few 14.00 runs.The biggest thing i seen that nite was the weather change.She might of just got one heck of a launch/hook on the street tires.Going to get a weather setup for sure.Ok thanks everyone.Looks like DR are next on the shopping list.