I can not imagine you did not find this out in a dream. 
Not quite, it was rather like one of those situations when lots of apparently unrelated informations suddenly start to make sense together when you stumble at the missing piece
Only one distinction missing: speed difference between ACURA power gear and Indy power gear.
This distinction was, in a way, already pointed out - by you
Many years ago you wrote, and a few years later I read, a "Tips for Newbies" article in which the powergears of Indy and Acura were called "flexible", in opposition to the GTO and Vette ones. That is the fundamental distinction: "rigid" (or boring
) powergear, the most common kind, works exactly the same for all cars that have it - to reach it you have to be at/above 225mph and the car must not have enough engine power to keep accelerating on its own by then. Flexible powergear, on the other hand, can be reached below the flat track top speed, and the minimum launch speed depends on the balance of forces acting on the car (including engine power, gear ratios, aero drag, steepness of slope, etc.). The launch speed for flexible powergear can potentially be much lower than 225mph, a fact that is evident on any Acura/Indy lap... The speed of the car when in PG is the speed of the car at maximum rpm in the (final) gear, so that's why Acura and Indy are different. If Acura had a value for mass that would give it rigid PG, however, it would never reach it, as the top speed is below 225mph (that is exactly the case for Audi, by the way). I like "rigid" and "flexible" terminology, guess I'll stick with it
So the drag really has nothing to do with it, and my kart has a very special unreachable powergear...
Drag does not affect the kind of powergear indeed, but it if the powergear is flexible it changes the minimum speed (higher drag leads to easier-to-reach powergear). You mentioned to be using mass=15 and drag=19. 15 is a flex-PG value (same as Indy), and 19 is quite low, so the minimum speed might be well above 156mph (have you tested going through a loop, though?
)
By the way, I'm probably sounding spoiled now, but it appears you where so exited about the second set of dimensions that you didn't mention were the car-to-car set is located.
Oh my bad, maybe I shouldn't have gone so far in skimming detail on that post
The range of interest is 0EEh - 0F3h, and values are in the usual x-y-z pattern. I will (try to) start writing some of this stuff (and more) to the Wiki now, so stay tuned
