I understand that many teams already use some form of optical rotary encoders so the market might not be as large...
but a gear tooth sensor setup with custom mounts for each type of COTS gearbox/transmission (IFI or AM).
Having good
sealed sensors and having them integrate seamlessly into the housings for either gearbox would be worth many times more than that of the kit gear tooth sensor ($5)
say... even $25-40 each (with sensor).... granted this is something that could be done with plastic injection molding.... but then one faces many of the same issues in higher
manufacturing costs discussed by Paul Copioli about the casting
-Bill