I'm slowly making progress with the C-Spec. The greatest issue I have at the moment is turning in late. I'm aware that I need to work more on turn in markers, but I find they are the hardest markers to define. I really must spend time at the start of my next testing session to firm up the markers I have spotted, and find clear markers where I have none.
Still, a 1.54.4 time isn't bad. I think the fastest drivers will be around 1.52.5 - at least with default weather. We won't know the actual weather used in the first week until it starts. After that, unless iRacing have changed something, we'll know the weather in advance for every single race week.
Another test session before the week starts, then it's back to the Skip Barber for races at Lime Rock Park, a track I've had success at for the last few seasons.