Author Topic: tachometer cable rpm  (Read 847 times)

mnahon

  • Full Member
  • Silver
  • ****
  • Canada, QC, Montreal
  • Posts: 436
tachometer cable rpm
« on: September 23, 2024, 18:37:27 »
Hi,

I'm wondering if anyone knows whether the tachometer cable spins at engine rpm, or some fraction of that? I'd like to try to set up a bench calibration of the tach similar to what Pawel did for his speedometer.
https://www.sl113.org/forums/index.php?topic=36590

Thanks,
Meyer Nahon
Montreal, Canada
1968 MB 280SL Auto Euro LHD Silver
2021 Tesla Model 3

mnahon

  • Full Member
  • Silver
  • ****
  • Canada, QC, Montreal
  • Posts: 436
Re: tachometer cable rpm
« Reply #1 on: September 29, 2024, 03:01:55 »
I'm going to answer my own question: it looks like the tach cable spins at half engine speed. I tried driving the tach with a couple of different drills whose speed I knew. In both cases, the tach read about twice the rpm of the drill.
Meyer Nahon
Montreal, Canada
1968 MB 280SL Auto Euro LHD Silver
2021 Tesla Model 3