3 Wire tach in 240Z

[greenmachine]

I have a 1971 240Z, stock and original L24 with 1983 280ZX dizzy, E12-80 module, and MSD Blaster 2 coil, and no ballast resstor. I am installing a later model 3 wire tach. Do I need resistor inline with the wire from the coil? If so, what ohm/amperage is needed?

I appreciate any and all advice!

[5thhorsemann]

I have a 4 wire early tach, wanna trade?

[zKars]

The inline resistor on the 75-78 280z's between the trigger terminal on the 3 wire tach and the (-) side of the coil is a 2200 ohm resistor (2.2K). 1/2 watt size should be plenty. I am using that resistor with my E12-80 module and that same tach and it works fine.

Edited April 2, 2012 by zKars

[greenmachine]

From what I have heard that tach will not work with the ZX ignition. Thanks anyway!

[greenmachine]

Thanks! Glad to hear it works with your setup.