Just an idea...instead of all race cars requiring a rev counter.(tacho)..each Club could have it's own kit.
The tool in picture 1 is a contact/non contact type.
Used as a non contact(Laser Beam) this will "read" all normal car engines whatever the ignition type. ie: conventional plug lead or coil on plug types as it "reads" of off a reflective tape (supplied) which is stuck to the crank pulley.
Bike engines would need to have an original type of tacho which I'm informed are available from bike breaker at a reasonable cost.
Cost is around £94.00 (Jack Sealey)
© Ted Shillitto Photography