If I could offer some advice, begin running before you finalize a design. Refine it as you go adding and taking away until you get what you want. My track ended up somewhat different than I envisioned at the beginning. It will evolve into what you need or want.
Couple of other things. A...
Hey Fireball. You're off to a great start. Planning a layout is always a good first step.
Had my own back yard grass track running a Stadium Truck series for three years (2019-2021). Layout below that eventually grew to 48in wide FR straight and turns 3&4. 54in RR straight and 60in wide at...