Had to jump on to my desktop and log in to hn to say thanks for this comment! Its (very subjectively) one of the coolest comments I've ever read on this site. I've often fantasized about doing something very similar. Spending tons of time in DiRT or Assetto Corsa and trying to use that in the real world. I've never actually succeeded but I feel like you've saved me from wondering "what if" too much. I'm still deeply jealous and seriously impressed by what you've done. Congrats!
Look into autocross, if you haven't before. It's probably the most accessible way to get a taste of time-trial racing in real life, and events are held all over the place -- basically anywhere there's a community and a free, empty parking lot. You just need a car (any car as long as it runs and is safe), a helmet (probably the most annoying part), and usually less than $100 for admission.
Had to jump on to my desktop and log in to hn to say thanks for this comment!... impressed by what you've done
Ha thanks, I have to say when I reflect on the experience it was about 10% "me" and 90% "others and the team". After towing the car home on faith that I would figure out the rest (my car maintenance experience was roughly changing tires and checking oil), I reconnected with a mentor who had decades of stage rally experience.
He ultimately invested tons of his time and effort into short-cutting me through many lessons and gotchas, even helping me rebuild the motor when it blew up before my 1st scheduled event. After awhile I called our rally team "God's Grace Rally Team" because the way it so quickly came together and succeeded so well in light of the many overcome issues was really a spiritual experience.
But yes, it can be done. Take that step of faith... reach out and ask for help too!