How to calibrate Rev-counter on GTV6?
How can I re-calibrate my Rev-counter? It works, but shows much higher revs than real.
'84 Red GTV6 3.0
Ok, I found the adjuster and it's not the one marked in the previous picture.
Using a program, I got a 300Hz (to match 6.000rpm) square signal out of my speakers, but only 0.5 Volts amplitude (should be 6-12V). I plugged the negative pole o it to the ground on the tach and the positive to the center bolt (marked with a red arrow in the pic.). I also fed the Tachometer with 9V DC (- to the upper bolt and + to the lower bolt).
I got no response on the Tacho , but I don't know if I plugged something wrong or if the square signal is just to weak.
Using a program, I got a 300Hz (to match 6.000rpm) square signal out of my speakers, but only 0.5 Volts amplitude (should be 6-12V). I plugged the negative pole o it to the ground on the tach and the positive to the center bolt (marked with a red arrow in the pic.). I also fed the Tachometer with 9V DC (- to the upper bolt and + to the lower bolt).
I got no response on the Tacho , but I don't know if I plugged something wrong or if the square signal is just to weak.
'84 Red GTV6 3.0
Hey Jose,
Did you come up with a solution for this?
I'm trying to work out what signal type a GTV6 tacho needs - 12v square wave, signal to ground or voltage spike
I also need to know what signal the tacho output of the Bosch Motronic M1.7 computer on a 24v is.
Pretty soon I'll need to get these two to talk to each other and I'll need to recalibrate my tacho to match.
Did you come up with a solution for this?
I'm trying to work out what signal type a GTV6 tacho needs - 12v square wave, signal to ground or voltage spike
I also need to know what signal the tacho output of the Bosch Motronic M1.7 computer on a 24v is.
Pretty soon I'll need to get these two to talk to each other and I'll need to recalibrate my tacho to match.
Sorry for the delay.
At first, I fed the tacho with 12V DC and got the 50Hz signal from the output of the transformer of my computer's speakers , but as then I could only adjust it at one ponit (1000rpm, or 1200rpm if 60Hz) it's not very accurate.
Then I could have access to an oscilloscope and a signals generator, so I could feed the tacho with sinusoidal signals 9-12V AC and 50-300Hz, and adjusted it to the highest. If you adjust it on the lowest then the error is very important when you reach 6000rpm (about 500rpm), and I prefered to have an error about 300rpm on the tacho at idle that vanishes as it goes up.
One more thing: the tacho was quite sensible to poor amplitude signals, that is that it gave different readings when fed with 9-10V both in AC and DC. Must check.
Hope this helps.
At first, I fed the tacho with 12V DC and got the 50Hz signal from the output of the transformer of my computer's speakers , but as then I could only adjust it at one ponit (1000rpm, or 1200rpm if 60Hz) it's not very accurate.
Then I could have access to an oscilloscope and a signals generator, so I could feed the tacho with sinusoidal signals 9-12V AC and 50-300Hz, and adjusted it to the highest. If you adjust it on the lowest then the error is very important when you reach 6000rpm (about 500rpm), and I prefered to have an error about 300rpm on the tacho at idle that vanishes as it goes up.
One more thing: the tacho was quite sensible to poor amplitude signals, that is that it gave different readings when fed with 9-10V both in AC and DC. Must check.
Hope this helps.
'84 Red GTV6 3.0