Calibrating 911 Carrera VDO Speedometer and Tachometer, How do you do it?
 

Help!

Has anyone ever calibrated their own speedometer or tachometer, I have the background in electronics but I don't have a procedure. I know, some may say just send it to a shop but I'm curious on how to do it, but just in case who in California can do it and for how much? Both are the electronic type VDO's, I suppose that if you gradually supply current at different intervals and compare a reading to a standard reference point this is how it might be done....help! Don't let me guess, anyone with a procedure would greatly appreciated.

Best Regards,

Alex

The 911 tachometer gets 3 ~12v pulses every revolution. I don't know if there is a means to calibrate it. See my post in this thread for a little more info. Tachometer pulses per Rev??
-Chris

a few guys have done the speedo. try my screen name and speedo in search.

Here is a way you can calibrate an electronic speedo without opening it.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=359385&prmenbr=361

Or, take it to a shop like Hollywood speedo, they put your car on a dyno, and calibrate your speedo to be dead nuts on.

Thanks everyone, this information is greatly appreciated.

Best Regards,

Alex