I have self funded my motorcycle racing for over 20 years. I have some rules before going racing and for the race effort also. These rules have allowed me to race for 20 years and still pay off my mortgage early.
1) All bills get paid first, this is non racing bills, mortgage, utilities, insurance, you name it it gets paid, even credit cards get paid in full before a race weekend. I pay them off every month, but don't let them sit till after a race weekend if I have them before.
2) Savings are funded for emergencies, racing is dangerous, you can break your clavicle, not one, but both to even it out (10 years apart). I also put away cash for retirement.
3) I don't buy stuff I don't need. I am closing in on 50, and have only had one new car, it was the most expensive car I have paid for, a 98 neon ACR (never made it to the track). I drove it for 250,000 miles. I paid cash, $12.700. I saved for a long time to get there. My next car was a 2.5 year old CRV, the only reason the neon went and the CRV arrived was that at the time was the CRV, at 12K was a steal, used value was 18K. Cash again, I will drive it until it at least hits 150K, then again, if it is still working I will keep driving it, it might make 250 like the neon. The only car payment I ever had was back in 1989 (used 87 Dodge Daytona) when I was getting sucked dry by college tuition.
Racing rules
Don't buy stuff you don't need with your race budget. My bike, a 2000 SV 650, bought as salvage in 2001 still has the original chain and sprockets. Most change the chain and sprockets to a 520 from a 525 right away. The bike came from Suzuki with the correct gearing for Loudon, so why change it, for maybe 3/10 of a second?. Spend the money on track time ,the bike is still faster than I am as it is. When the chain and sprockets wear out, I will replace them with a 520. For the first 2 or three years, I ran the stock exhaust and a set of clubman handle bars (35 bucks vs 150 for clip ons). Money was tight then, and what funds I had were used on the things necessary for the track. Spending money stuff you don't need, then not having money for track time sucks. Ask my friend, just cant get him to understand, but he does it all the time.Maintenance also comes before cool stuff/paint/performance upgrades.
Race what you can afford, I run the light weight class, tires are cheaper and last longer. The lightweight class is faster than the middle weight classes were when I started racing in the early 90s. Racing light weight allows me to race more.
I camp at the track and bring most of my meals, that saves a lot of cash, 200+ for a couple nights lodging, (non leaf peeper weekends in NH) plus meals. That will cover an all day Thursday test and tune, the gas used on the track and to and from the track.
Don't buy exotic fuel if you don't need it. Suzuki say 87 octane (maybe 89) and my motor is stock, so I use 93 pump gas, splurging here. My friend likes running the expensive stuff in the 5 gallon cans at the track, another waste of cash as his engine is stock also.
PS: Not having kids does helped also. Not sure how people with kids do it.
Just a few thoughts, could keep rambling, with more gammer mistakes, but I think you all get my points. If you don't bills to live first, savings, don't spend what you don't need to, in life and racing.
PPS: If some one wants to fund my racing I am open to it.