Absolutely keep the car you have.
Good Job on the Lack of Debt
And I want to commend you on having no debt. That is awesome. So many Americans at your age are stupidly burying themselves in debt. It is an epidemic in this country. It leads to so many complaining about how hard it is to get ahead, to make it, and then they start looking at and blaming "the system" rather than themselves and their own choices. It must be somebody else's fault, right?
My Advice Is Different
I'll go against the grain here, though, and say saving for the future at your age is so much more important than going into decades of debt for a house, especially in your early 20s. Maybe do both, but if you are not even married yet, guess what? Your needs/wants for a house are going to change when you do.
A Hypothetical Example
If you are 22 (had to guess), and have $10,000 invested already in, say, VFIAX (or pick your own low expense - .04% - passive index fund), and get a 10% return, investing just 500 bucks a month, that will be $6,124,793 when you are 67.
$6,124,793
Is 10% too optimistic? Fine. I wont argue. Use your own numbers. Maybe plug in 8%. You still end up with almost $3 million, $2,998, 907, and this assumes you never put in more than $500 a month, which is an unlikely assumption. But you have to start early, which means today, not putting it off until you are older. Wait until you are 35, because, hey, I have to buy a house, and I have time, and that same 500 bucks a month invested barely cracks a million at age 67.
www.ramseysolutions.com
A Real World, Non-Hypothetical Example
My eldest son is 24, and he listened to me from a young age (can you believe that? Actually heeded his old man's advice?), and he already at 24 years of age has a net worth in six figures. He did not buy a house yet. He rents.
Conclusion
So, there is my advice. I hope you take it. I realize it goes against what everybody else in the world is telling you ("Go by a house!" "You have to buy a house!" says the crowd), but it is just math. Because it is just math, there is no reason why any American cannot be a millionaire or multimillionaire if somebody just explains this to them when they are your age. Now somebody has explained it to you, and you are your age. Next year, you won't be. And with each succeeding year the same goal becomes more difficult. Starting early is important. Don't be those folks with the big house, a refinanced mortgage, and no wealth when you are in your late 50s and wondering if it is time to start investing for retirement. You are smart and wise, as your lack of debt shows. Take the next step. Run the numbers for yourself and get started right away. Time is your friend when you are in your early twenties. Later, time is an avenger, and it runs out sooner than you think.
Oh, About that Car
So back on topic, if you love your car, run it at the track. Who cares if others have a 5 liter? Just do HPDE for now. Get some stickier tires for the track than PS4S, which are my winter street tires (Georgia winter, lol), but you'll take seconds off your lap time with a stickier set of tires. If you decide you want to compete, follow the advice of others above and take a very careful look at the rule book and in what class can be competitive with the engine in your car, and then modify only what is allowed in those rules.
Good Job on the Lack of Debt
And I want to commend you on having no debt. That is awesome. So many Americans at your age are stupidly burying themselves in debt. It is an epidemic in this country. It leads to so many complaining about how hard it is to get ahead, to make it, and then they start looking at and blaming "the system" rather than themselves and their own choices. It must be somebody else's fault, right?
My Advice Is Different
I'll go against the grain here, though, and say saving for the future at your age is so much more important than going into decades of debt for a house, especially in your early 20s. Maybe do both, but if you are not even married yet, guess what? Your needs/wants for a house are going to change when you do.
A Hypothetical Example
If you are 22 (had to guess), and have $10,000 invested already in, say, VFIAX (or pick your own low expense - .04% - passive index fund), and get a 10% return, investing just 500 bucks a month, that will be $6,124,793 when you are 67.
$6,124,793
Is 10% too optimistic? Fine. I wont argue. Use your own numbers. Maybe plug in 8%. You still end up with almost $3 million, $2,998, 907, and this assumes you never put in more than $500 a month, which is an unlikely assumption. But you have to start early, which means today, not putting it off until you are older. Wait until you are 35, because, hey, I have to buy a house, and I have time, and that same 500 bucks a month invested barely cracks a million at age 67.

Investment Calculator
With our investment calculator, you can find out how much you can expect to have in your retirement portfolio over time.
A Real World, Non-Hypothetical Example
My eldest son is 24, and he listened to me from a young age (can you believe that? Actually heeded his old man's advice?), and he already at 24 years of age has a net worth in six figures. He did not buy a house yet. He rents.
Conclusion
So, there is my advice. I hope you take it. I realize it goes against what everybody else in the world is telling you ("Go by a house!" "You have to buy a house!" says the crowd), but it is just math. Because it is just math, there is no reason why any American cannot be a millionaire or multimillionaire if somebody just explains this to them when they are your age. Now somebody has explained it to you, and you are your age. Next year, you won't be. And with each succeeding year the same goal becomes more difficult. Starting early is important. Don't be those folks with the big house, a refinanced mortgage, and no wealth when you are in your late 50s and wondering if it is time to start investing for retirement. You are smart and wise, as your lack of debt shows. Take the next step. Run the numbers for yourself and get started right away. Time is your friend when you are in your early twenties. Later, time is an avenger, and it runs out sooner than you think.
Oh, About that Car
So back on topic, if you love your car, run it at the track. Who cares if others have a 5 liter? Just do HPDE for now. Get some stickier tires for the track than PS4S, which are my winter street tires (Georgia winter, lol), but you'll take seconds off your lap time with a stickier set of tires. If you decide you want to compete, follow the advice of others above and take a very careful look at the rule book and in what class can be competitive with the engine in your car, and then modify only what is allowed in those rules.
