As for my experience, the adjust-parameters are corner speeds, while the ratio parameters are top speeds. Be careful to change those values in slow steps until they fit your need. One thing I did for all tracks was to narrow the adjust parameters. The gap between "worst" 0.80 (= 80%) to "best" 1.20 (120 %) is too high, because "best" would be 50% faster than "worst" with these settings.
I once set best adjust to 10.0 instead of 1.0 and had nearly the complete field crash into the first corner at Watkins Glen, because AI indeed tried to go at 1000 % through this corner. It looked funny, but was highly unrealistic of course
. Cheers, rainer