but there's no free lunches ... don't forget there's a significant cost for lost acceleration while hanging on to excessive revs (say, over 8,000) where engine power is drooping. It's a balancing act based on the total energy (power x time) you generate over the full rev range and all gears, not simply the higher the revs just after you change.
the magic rpm point in each gear can be calculated to deliver max energy/acceleration. this video clip clearly indicates it won't be as high as 8,500 - since the rev limiter is cutting power completely
