I guess overall to explain the racing gobos speed. the NPC racers are running on the same script as the player's. It is very possible to have your gobo have the exact same stats or better than any given gobo. The speed in a race is affected by the age( really only a factor if they're over 25), they're hunger, their mood, and their opinion on racing and the type of race. Some may just hate racing in general, some may hate the specific type of racing. Feeding a gobble is a good tell for what they like and dislike because they will actually tell you after you feed it the first time BUT that is also dependent on the personality of the gobo there are four personality traits that affect the opinions of gobo, and there are four personality traits that affect their mood and how they do in any given mood.
Some personalities may be erratic they may shift what they like or dislike randomly each day they may change slowly over time. Some personalities only affect their mood and not their opinions so you could have a bad gobble that may get better over time or may randomly get better or you could have a good gobble that randomly gets worse or will slowly get worse.
Overall it's a case of experimenting seeing what you get and keeping track of what you think does what.
I will give this hint, it is far more likely to get a personality combo that doesn't affect their opinions, and will only affect their mood and there is a personality combo that effectively no matter the mood it will be like they're in a good mood and do as well as they would in a good mood and there's also the opposite where there's a combo where they will just do bad no matter what mood they're in there are eight personality traits in total. 4 that effect mood and 4 that effect their opinions.