Modify 80 Tacho from 6Cyl to 8 Cyl

[djroberts]

Does any one know how to do this? I have recently converted an 80 from 1fz to ls2 and the tacho doesn't show rpm. I understand it can be done with a potentiometer but i am at a loss as to where i should start.

Thanks, d

[davewanna]

Unfortunately it is more complicated than that. Different number of pulses per revolution, so even if it makes the tacho move, it will not read correctly. A lot of V8's share the same tacho pulse rate with 4cyl engines, not that it will help you in this case. You will need to change the pulse frequency with something like this... http://www.jaycar.com.au/productView.asp?ID=KC5378" onclick="window.open(this.href);return false;
And even then the pulse output of this kit may not be right to drive your tacho. It will probably need a custom piece of electronics, I am currently building one for my V6 powered Bundera.

[Shadow]

you can change the tacho output from the LS1 computer to suit different tacho's. need someone who can program the LS2 ecu, then it should be simple.