Tach out put
 

If I remove the stock cumputer and install a Microtech, Can the stock tach give me a correct reading from the microtech tach output?

if you have a LT the tach output comes from the factory output off the coils,
if you have a LTX the output is form the ecu, it is a standard square wave output,
so yes your factory tach will still work.,

Dale

"correct reading" is a loose term. My stock tack is usually off +-400 rpm

you need to calibrate the tach then

How to Calibrate the Tach
 

How do you calibrate the tach? Does it use a resitor or is there an adjustment screw in the tach

Thanks to RETED for this snippet of info:


Not a problem for an FC...

There is a "calibration" screw on the FC circuit board that you can adjust so the revs should match. We normally calibrate the instrument cluster with a simple stand-alone uP to handle such adjustments. You probably can do this by looking at the RPM display off your Microtech and adjust the needle until the RPM's correspond correctly. I can't confirm if this works on an FD3S intrument cluster...

"stand-alone uP". What and where can I find one of those? Back In the day, my S-AFC exhibited the off readings too. I Imagine the LT8 will posses the same variance.