Bob: Remember that you can join during qualify, that usually takes place roughly between 8,10pm and 8,15pm. Unfortunatly it is not possible to set the server to allow people logging in during warmup
How many laps would one guess a stint is? ....Umm, on a dry track.
Let's see, I'll assume an average pace of the fastest guy at... 1:09,500, or 69,5 secconds. Furthermore I'll assume 70 seconds lost in pits. 67 minutes = 4020 seconds, and if we subtract pitstops we are left with 3950 seconds. If we divide this by 1:09,500 (69,5 seconds) we get 56,83, iow 57 laps (as it indicates 67 minutes will be up when the leader is 83% done with his 57th lap.) If we are to have 58 laps, the average lap time of winner must be better than 1.09,300 (3950/57=69,3 sec), still assuming 70 seconds is lost in pits.
Conclusion: I am 80% sure it will be 57 laps in the dry, but with a flawless race some of the big 4 might make it 58 for those not lapped
EDIT: A stint u said, not a race, in that case 19 laps for most.