Been discussing doing Daytona 24 hours, also in the C7
Not sure if I fancy waking up at 3am for a graveyard shift though!
Looking back at last year's I was surprisingly nervy in our 24hrs. We were in the 4th server (so high in the rankings) and I'd not done an awful lot of running for 5 or 6 years (a handful of iRacing races but nothing much). I did runs on practice servers and a few in the warmup before the race itself, but when it came to it I found I had the graphics turned up too high and when there were 3 or more cars directly in front of you the FPS dropped to around 40, which made it quite choppy (read scary) trying to negotiate through the traffic.
After sleep I found the 1am stint much more comfortable - I guess the natural tiredness helped relax me and I felt back to my old self, not really thinking and just driving on autopilot (which thankfully I've always been able to do). This was the 3rd or 4th 24hr race we'd done and more often than not I get a graveyard stint - it's usually quite relaxed, at that point aiming to get it through the night as much as anything, as the pace tends to come naturally at that point.
The hardest bit is getting your body as ready as possible by going to sleep earlier and earlier so you're not dead on your feet when you wake up. Le Mans is particularly bad for this - the first year we did it at Le Mans (NR2003 GTP mod) there were at least 2 accidents where people thought they were on a different straight and missed the corner, destroying the car when it creamed into the (solid) tyre barriers at nearly full speed, simply because the Mulsanne straights look similar and they got confused through tiredness. Obviously that's not going to happen at Daytona, but it shows the silly mistakes you can make if you don't try to do things properly!