Bracket racing was created for this very reason so cars of unequal performance could compete against each other. Otherwise the guy with the most money is going to win 99% of the time. If that's you go for it, but just remember there is always going to be someone faster than you.
Just for the record though if you haven't gone bracket racing maybe you should give it a try. It's not as easy as it sounds and you have to race both ends of the track. There are a lot of good racers out there, and it takes more skill and talent than you imagine.