I would be interested to see what the standard curves show, in my thinking, there is no point in taking the car to 6500rpm, if peak power is alot lower.
My old Zafira GSi was 270bhp and would rev to just shy of 6800rpm, but peak power was 5500rpm. So I never took it any higher.
The point was proven at Santa pod, first run taking it to about 6400rpm provided a 15.6 second run.
On the several runs after, and going to a max of 5400rpm, the best time for me was 14.78 seconds. I felt weird as i I was changing too early but it obviously worked, and the inlet temps were not as high.