Well, there's maintenance and then there's working on shit over and over again. If you're rebuilding motors, redoing suspension, and yanking transmissions every other day forget it.
during race season I consistently spend 40ish hours a week wrenching on average. Some weeks less some weeks more.
Im always adjusting and changing stuff to get faster. I move lead and scale the car weekly
Normal week, work job 7:30-5. Home at 5:30, in garage from 6-12. M-Thur
Monday is reset shit back to base line settings, nut and bolt, inspect everything
Tuesday is decide make changes, scale, adjust, scale, etc..fix what was found inspecting on monday.
Wed is usually clean air filter, fuel filter, change fluids, grease everything, check Toe, caster, camber, etc..
Thursday is tire prep night, pressure wash, clean, sipe, groove, grind, mount decide on backspacing etc..Plus load truck and trailer
Friday leave work a little early, home at 4, load car, feed dogs, Get to the track at 5pm friday, usually home at 3 am sat.
Up at 8am sat work on car until 1pm, leave for the track at 2, get home at 3am.
Up Sunday at 9am for wash day and reorganize the trailer.
Thats April through Sept. There are race nights that we get home earlier but there are also nights we get home at daylight.
It gets much more difficult/hectic if you get torn up on Friday or Saturday.
I was running low on spare parts late in the year and the race shop wasnt open on Saturday. I was fighting for points and stopped racing on Fridays.
I refuse to have DNF's because im lazy during the week. Mechanicals happen, shit breaks unexpectedly, flats, etc..I can deal with that, its just part of it.
I love it but with all that being said, i can see getting totally burned out very soon.