SupraJerry;1554515 said:i'd like to know too.
after all, the 'expers' all say that OEM tachs are not accurate.
i guess that the sarcastic replies are from people who don't know.
IJ.;1554691 said:
To answer the original question I'm assuming you have an 86.5 with a GTE swap?
If so you'll need either a GTE Tach or do a resistor mod to the 86.5 NA Tach to make it play nice with the Turbo ignition.
89nasupra;1554736 said:If you changed the harness and ECU you will have to change the tach to a turbo tach or change some resistors on your current tach.
Caveats:
the NA tach does not work with the turbo engine->the difference is in the ignition systems (distributor vs. CPS and coil pack). In order to make the NA tach work with the turbo engine you have to change some resistances in the tach PCB itself. I figured out the rewire for the NA tach, see it here.
http://www.supramania.com/forums/showthread.php?113579-Non-Turbo-to-Turbo-(NA-T)-FAQ