The Engine Speed figure depends on what they used to set the RPM of the Rollers against. Has the car got an accurate Tacho?

The peak RPM figure of 8450 is VERY concerning, but a discrepancy there explains why the graph isnt as expected.

The mention of 5k, where did that come from? Are you saying that he thinks that the car didn't exceed 5k on that run? That's unlikely. A run would normally only end if.....

1. The Rev Limit is reached
2. The car stops making power
4. The operator aborts the run (if he hears Det or if the car is unstable on the rollers etc)
3. It self-destructs

However, the lines crossing depends TOTALLY on the configuration of the Graph. They will only cross if the Axis' are equal.

Post the graph so we can make some sense of it.