I had some fun a few years ago developing a replacement circuit for Ferrari 308/Mondial ignition ECUs, and then subsequently the ones for the 328/Mondial 3.2/Testarossa cars. It was interesting to see how crude but still effective the original circuits from the 1980's were, but also how much polish I could give to it while retaining form/fit/function compatibility, using an ARM Cortex-M0 and other modern ICs available to me.

One of the biggest updates I was able to do was to add a much more rugged power supply. The original boxes get fried easily by dirty jump starters, pulling the alternator while running, etc. It was pretty easy with the components available now to make a new circuit that protects from all that.

The most interesting thing to me was that when I went to a more modern ignition map rather than the crude 8 stepped curve they had originally implemented, while testing showed it produced more power and better emissions, people beta testing for me reported it felt 'too smooth, less fun'. So I went back to the original crude steps <shrug>.

Anyway, it was an engaging project that taught me a lot about engine ignition, and I've now sold about 100 boxes and helped keep these old classics on the road.