clutch and 2 speed is very important.
example, on same track no engine adjustments, just clutch and 2 speed, saturday i struggled to make run time in 18 laps. sunday morning struggled. changed clutch settings a little, and earlier 2 speed engagment, and i made 5 mmins easily enough, but more importantly, for 19 laps this time.
Drag, condition of bearings, and maintaining the correct split, all go towards seconds of runtime. sometimes that is what counts. you miss finninshing a qualifier by 2 or 3 apexes, and these seconds then count.