SportWagon
Why start with the Nurburgring?
Wouldn't you earn nearly the same amount of points in less time using a shorter track?
Hmm. You seem to say that the subclasses of cars are somewhat track-specific? Is that correct?
It looks like you are starting ponder some of the deeper mysteries of B-spec, so specific language is helpful to describe the points which have been classified. Keep track of Track Vs Floating points, they behave very differently. Floating Battle Points alway seem associated with (floating) Machine Points - they seem to have the same classes and requirements. These classes seem to behave in the way your illustration describes, but the classes have never been defined.
The JP author describes the sub-class as A1, A2, B1,...,D2. I have found no evidence that these sub-classes are useful to describe anything other than the specific tunings for the cars used on Nurburgring. These classes seem to be strongly related to A-spec points, but no direct link has been found.
Track Points behave very differently than Floating points (track classes are defined as A, B, C, and D). A car can be tuned between classes (i.e. Miata A to Miata B), but the car can only collect points from one class at a time. Track points are not very tune specific. A reasonable guess will provide a fairly accurate estimate of which class a car will qualify for. Any car that collects any Track points should be able to collect all Track points for it's class.
An accurate measure of which Track points a car quailified for would be to clear points from 4 tracks using the JP cars, but leave one set of points on each track to test cars and various tunings. This seems like it would require an unreasonble amount of testing. I have suggested in the past that someone might make a chart of the likely opposition for Family Cups at any given level. Testing on these cars would then provide a comparison for any car and tuning entered in a Family Cup at level 0.
Do the ring first because the points are earned quickly - 30 to 40 races for 7000 points compared to 228 races (plus repeats) for 3000 points. Once you are sure no more points can be earned at Nurburgring, then only 4 tunings are required (A, B, C, D). It helps to be very organized so no tracks get missed.
Miata C and RSC A are very specific to the Ring (and a few other tracks). The other tunings seem to earn points anywhere. The Lupo earns points slowly. The Dodge RAM on the Ring at level +10 found floating points I didn't know were missing on my clean-up game.
Another random note on your chart. (I'll use B and C as reference points, but they don't describe floating point classes). I suspect Car X would quickly earn all points directly above it's class, and draw more slowly from the points under the B than under the C. I have made some observations which suggests that I could earn these points more quickly by tuning the car with ballast weight or downforce, sometimes tires.