Earlier quoted context omitted.
To phrase it maybe a little more provocatively: how would you accomplish the precise timing necessary to achieve spherical implosion? This was possible with analog electronics in 1945. Surely in 2026 we can also build analog piezoelectric fuel injection systems.
To play devil's advocate, this starts to get into the territory of, how do you define a computer? If the analog circuitry is using sensors and passive components to inject fuel at spark at just the right time under varying conditions, "computing" them, one might say... Maybe "no integrated circuits" might be a finer line.
To be clear, I don't think making elaborate analog ICs would be really "cheating" so long as they don't put a generic von Neumann machine on it.
EDIT: to be more clear, what I'd be trying to achieve with a rule change like this is making "computation" a somewhat larger investment in time and difficulty. By and large, at least in my opinion, profligate, non-essential computation has enabled many of the things that have made the sport less interesting. It's also made cars suck a lot. This would impose kind of a tax on those things.