80 mm Tachos (RCA50 ***)
Farringdon tachometers (rev. counters) use Swatch designed stepper motors to give accurate, typically + or - 1%, readings from a variety of sources including the negative side of the ignition coil and sensors picking up targets on the flywheel or camshaft*. The stepper motors are controlled by a microprocessor which allows the tachos to copy period chronometric action and to control the tell-tale hand in different ways.
A new Filter* design has proved successful in taming the most powerful of new ignition systems for historic cars and providing steady accurate readings from the negative side of the coil.
From August 1919, tachos will be fitted with eight way M8 connectors on the rear of the enclosure and supplied with a cable and matching over-moulded connector and will have the new filter fitted inside the tacho case.
Shift Lights will no longer be supplied with every tacho but will be available to order separately. The new type has a threaded metal body held in place with a nut behind the dash.
*Call Farringdon for information on sensors and the new Filter box.
100 mm Tachos RCA51 ***
120 mm Tachos (RCA52 ***)
Above left is a replica tachometer fitted to an Aston Martin DBR1 and other cars of the period. Centre is a replica of a Jaguar D Type tacho. In period, these were fitted to some light-weight E types used in competition as the production electric version did not have a tell-tale needle. On the right is a Farringdon version of a 120 mm tacho.