Can someone please help me undertsand the dip in the following logs.

So I went to Cecil last night and got some log data. Car was doing good 10.88 every run and I wish I was bracket racing. The goal of the night was to get data and test the one piece drive shaft. I have attached two logs and would like to understand why the torque is dropping between 1-2-3 and 4-5 shifts. The drop does not occur during the 3-4 shift. I feel like I'm looking a gift horse in the mouth as I got 131 Mph each pass and it was screaming for a stock car. I tried to correlate data but was left scratching my head and the only thing I can think of is wheel slip during the shifts. Anyone have any thoughts or insight into this?

Attachment 104048
Attachment 104049
Attachment 104050

Did a search on the forums and didn't find anything relevant.