manic
15th January 2017, 08:07 PM
I finally got round to calibrating the tachometer on the tdi today. There is no switch combination that will read the RPM from the alternator signal correctly. It needs to be fine tuned using the gauges adjustment screw. I used the setting that got it closest to 750rpm at idle for starters.
To figure out my actual idle RPM I stuck a strip of yellow electrical tape on the crank pulley and filmed it at 100 FPS on a gopro.
I used PotPlayer a free video player that supports frame by frame playback and shows frame count. Use the tab key to show frame info. F key to advance, D key to go back a frame.
Count rotations in 500 frames (5 seconds) * 12 = actual RPM.
My guage was around 200rpm off. Now adjusted and accurate.
One way to do it if you can't think of another.
To figure out my actual idle RPM I stuck a strip of yellow electrical tape on the crank pulley and filmed it at 100 FPS on a gopro.
I used PotPlayer a free video player that supports frame by frame playback and shows frame count. Use the tab key to show frame info. F key to advance, D key to go back a frame.
Count rotations in 500 frames (5 seconds) * 12 = actual RPM.
My guage was around 200rpm off. Now adjusted and accurate.
One way to do it if you can't think of another.