Originally Posted by
FABombjoy
I'm sure there are a lot of ways to go about this, I just picked one that made sense at the time.
I still have the advance mechanism intact. In a crank+cam signal setup you don't have to clobber the mechanical advance.
Because the advance weights are still there, if the tooth is mounted to the shaft, it's expected position relative to the crank wheel might change.
Normally the tooth is only read at startup and it probably would always appear in a fixed position. But if you ever have a crank sync error, depending on your RPM a small tooth might miss the sampling window. It was easier to make a half-moon shape and set Megasquirt to look for cam tooth right in the middle of the range.
Probably in an OEM computer situation, a full predictable half-moon would net you a faster full sync?