The problem will be that the days of a part-time champion driver are long gone..
You would need and want to give 110% to the race car driving, and not want to have to worry or bother about "business headaches" and problems, unless you are going to just to it as a part time hobby.
At 23 years old, I would ditch the businesses in a heart beat and focus on the racing.
In 8 or 10 years a race-shop being run by an ex-champion will be far easier to grow and promote, than a current race shop being run by an also-ran mid-field contestant
