Log book question
be carful with those run predictors. I have seen guys use them but not for very long. it may get you close every once in a while, but more times than not will leave you hanging if you use it to dial your car. the best tool is a big log book full of runs with a car that has been set up and not touched. study it and you will learn your car like the back of your hand.
this is just how I do it.
I'm about to run first round and need to dial the car. I just went a 6.78 on my practice run. looking back over my log book I see that my car almost always speeds up 2 numbers after my first pass of the day, because now all fluids and the drivetrain are up to temp. to account for this I need to put a 6.76 on the car.
I also look at my weather station and take note that the density altitude is 1278ft. at this point I look back through my log book and find runs I have made with a similar DA. I find 3 runs and the ET's were 6.772, 6.767, and 6.759. I use these runs to confirm that a 6.76 is the best dial in.
I cut a good light and have the guy in the other lane covered by a mile at the finish line. I drag the brakes just before the finish line and run a 6.812. Now how do I know if I was gonna run my 6.76 dial in or not? well, I take the ET slip look at my 60 ft and 330ft times. I now go to my log book and look at runs with similar 60 ft and 330ft times where I made a full pass, and check to see what ET the car ran on those passes. i find 4 passes that are close, and the full track times were 6.771, 6.766, 6.763, and 6.770. I can see that the car was on track to run the dial in or just a few thousandths over. to double confirm that you could take your current 330ft time and subtract your current 60ft time from it to come up with how long it took you to get from 60ft to 330ft. now do the same with those 4 similar runs in the log book, and see how close the numbers from the old runs are to you current one. the same can also be done for 330ft to 660ft. say on those 4 old runs you have subtracted the 330ft time from the 660ft time. now you add them up and divide that number by 4 to find the average for those 4 runs. say you're average came up to be 2.598 seconds. take that number and add it to the 330ft time on the run where you were on the brakes. say that 330ft time was 4.170. well 4.170 plus 2.598 is 6.768. so looks like you were on track to run your dial in. take that info and use it to dial for the next round.
long winded I know, and kind of off track with the original question. however, I wish when I first started bracket racing that some long winded clown would have posted something like this for me to read. hope it helps somebody. I'm going to bed, lol.