In my create-a-team GT team I stopped spending after race four in the first season. I had changed the budget to give the max amount to next year’s car, so I was still losing a lot of money, but I had told the boss I expected to finish 10th meaning there was no pressure, and when I finished 9th everyone was happy.
In season two I still haven’t built any buildings and the car is better, but still comfortably the worst on the grid. Only gaming the hybrid recovery systems, (not an option on open wheelers), is giving me results.
I did pretty much the same in my open wheel game where I took over ZRT, which I think are the second worst team available, except there I did go into the red to buy the factory upgrade to get to 20 staff.
There are some clever options you can combine to really help with results, (that aren’t as obviously over-powered as the GT hybrid systems).
Firstly, you can sign a pair of pay drivers who have high marketability and just rake in the cash regardless of where you finish. The drivers won’t be great, but if they’re both paying you 250,000 a race to drive for you and both are bringing in sponsors also, then you can build up an excellent infrastructure and then switch to actually talented drivers a season or two later.
Another direction, (the one I took with ZRT open wheel racing), was to embrace the very high “smoothness” rating of my lead driver and pair him with a race mechanic whose first unlock was to make soft tyres last much longer. When refueling was banned in season two I could use practice to get 10% performance increase on soft tyres, then combine my driver’s natural ability with his mechanic’s unlock and I could sometimes almost run the entire race without a pitstop and still have ~28% tyre life left at the end. If the race is 30 laps then avoiding stopping just made your car maybe a second a lap faster.
Because refueling was banned there was no point where anyone else was running a much lighter fuel load, so they couldn’t sneak that time back on me.
Also, if you are going to pit, think about doing it significantly out of sequence. I had success with a driver that couldn’t overtake by pitting him super early. This meant he came back out of the pits into totally clear air with no cars around so he could go as fast as his potential allowed (seconds faster than in traffic), and by the time he was closing up on the field they were starting to do their pitstops, so he just cruised by without having to overtake anyone on the track.