Yet Another Tach Question

[280EZRider]

I have concluded, possibly inaccurately, that the tach used on a 300D Turbo is electronic. Therefore, the infamous tach-amp, that never seems to work properly, takes the place of the signal generated from the distributor to the electronic-ignition box of a gasoline engine. The question then is: Would a tach from a 300D (5 cylinder) work on a 6 cylinder gasoline engine if wired to the distributor-to-electronic-ignition box?

[Tomguy]

Only if you don't mind seeing your RPMs as higher than they actually are.

If you could modify it to work, you're talking an engine that fires 5 times every 2 revolutions vs one that fires 6 times every 2 revolutions. That's 2.5 firings per rev vs 3. If you're doing 3000RPMs, the gauge will read 3600RPMs. 5000? 6800. Not a good way to judge RPMs...

[280EZRider]

This is a good point. Thanks!