I think your dyno run was clipped off at the low end and high end. I found another 6S dyno plot that is clean from 2500 to 6400, and is much like Mazda's advertised power curve:Further analysis. Our torque curve is relatively flat from 4500 to 5200 - meaning this is the range where the car pulls hardest. If we look at this 700rpm sweet spot range:
With 25.5" tires:
Sweet spot torque:
From the video, you can see the car accelerates well up to about 100mph. I am shifting from 4th to 5th at around 100, just as the toque curve is dropping off. But when I get to 5th, I am well below the sweet spot of the torque curve and the car falls flat - damn 0.733 5th gear!!
I used that torque curve as an input to my "shift points" Excel program, as well as the gear ratios, and the tire diameter. The result is the torque at the front axle vs speed for each gear.
I created jpeg picture files ( on smugmug ) of the plots from Excel, but I can't make a picture here. ---- Any ideas?
The bottom line is it's best to stay in the lowest gear possible, and when I ran a 6 speed (common in Oz), you have more axle torque in 3rd, 4th, and 5th. They hit 6400 sooner in each of those gears: 3rd is 82 vs 90, 4th 104 vs 120, 5th is 127 vs 155, and 6th is like a continuation of 5th, hitting 6400 at 142.
More later ...