[Pampered-Z]

First off, both runs are fairly close and the ET to MPH seem on par.

Could be a bunch of factors? What does the car weight and what gears do you have? what RPM did you shift at each time. What gear are you in and what RPM are you at when you cross the finish line?

How close together (in time waited) between runs were the two. Hot tranny
and convertor could slip or just not shift as crisp. Hot vrs cold engine could effect you top end (speed = horse power) more then you 60' (launch traction + torque). Shift a few hun RPM to low or over the torque curve could effect your run as well.

What you really want to do it keep launching the same way, shifting at the same RPM and see what happens. Next time near the end of the day do a few 'hot laps' after the race drive right back to the starting line and run again and see how the car reacts!

Also, you have good 60' times But you need to always stage the same and then you can use it as a gauge as to how hard the car is leaving the line.
There is some margin of movement when you stage so remember that how deep or shallow you stage will allow you to or not to,, "get a running start" at breaking the starting line beam.

Shallow stage, you get a running start, but you made the track in effect longer but you begin the get the 3600 lbs?? of car moving before you break the beam.

Deep stage and you do the opposite, your closer to the finish (and 60' trap) but you have less distance to excelerate in.