When did Ferrari first put a trigger wheel on the crankshaft harmonic balance wheel? Would that balance wheel fit on a 308 crankshaft?
I think that the 1981 308 GTBi was the first Ferrari road car which used a trigger wheel on the flywheel to check the engine speed and position, and a phase wheel to sense the cam phase (TDC). That happened with the introduction of the Magneti Marelli Digiplex MED801A, a successor of the last Dinoplex (AEC104B) ignition (actually it was the successor of the Magneti Marelli SAE 701A but this one is so rare that probably no one knows about it). The Digiplex ignition system was the first microcontroller enabled ignition by Marelli which managed the ignition timing based on the speed and load of the engine and timing tables stored in an on board EPROM. It still required a distributors to distribute the spark to each cylinder. To relate to your other post, this setup is different to the fully electronic EDIS ignition, which does not detect the cam phase/TDC and thus fires a spark in the ignition and in the exhaust cycle (this is why its called "wasted spark" system). Unfortunately the trigger wheels are not compatible to each other.
Adrian, I have an 82 308 and started looking in to converting the ignition to COP with SMFI and a Motec to manage. Will I need an additional trigger wheel to complete the job? Thanks Tommy A
Tommy, i haven't installed a MOTEC setup yet. It should work, as the MOTEC seems to be able to work with a phase and a trigger wheel setup, but you want to ask the manufacturer to be sure.
Adrian, Your early trigger wheel functionality history cleared up that adaption- thanks. So far, welding 3 studs on 308 2v (carb) crank harmonic balance and clamp on ALT brace mod for sensor looks most tidy. Now searching threads for pics of sanitary installation of (EDIS-8's) 2 coils & spark plug wires routing- hate bird's nest look.
