at what point do you shift how you study for CARS?

I've been practicing CARS by doing 3-4 passages everyday (for about 8 days now) without a time limit or a focus on the aspect of how quick I could do it since I'm trying to first understand the type of questions and how to navigate passages etc.

My question is, when do I start shifting my focus on finishing on time? How do I "effectively" gauge my ability to understand passages so I can safely move on to actual applications? My performance thus is pretty unpredictable but my overall accuracy is 73% (for a total of 234 questions).