Tachometer calibration
08-16-2016, 11:51 PM
#1
3rd Gear
Thread Starter
Join Date: Dec 2014
Location: Central Tx
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Tachometer calibration
For fun I tested my 89 951 tach's accuracy while I had the cluster out for dash replacement. It was reading about 7250 (for 7k input) so I pulled it out of the cluster and made a small tweak on the upper adjuster.
Pictures show results. The counter displays in khz hence leading decimal.
Formula: RPM X 2 / 60 = CPS
233 cps: 7k
133 cps :4k (camera angle off. very close to 4k actually)
66 cps: 2k
Connections from rear. Left:Signal Center:Ground Right:12v
Pictures show results. The counter displays in khz hence leading decimal.
Formula: RPM X 2 / 60 = CPS
233 cps: 7k
133 cps :4k (camera angle off. very close to 4k actually)
66 cps: 2k
Connections from rear. Left:Signal Center:Ground Right:12v
08-17-2016, 08:24 PM
#3
Very neat!
Just as a word of advice, pull the speedometer and see if the odometer drive gear has been replaced yet. If it hasn't, I would suggest doing it now and save yourself the headache later. If you see the brown gear in the pics here: http://www.klaindustries.net/gearinstr/gear-instr-1.htm you'll want to order a new gear and install it.
One of those "while you're in there" things...
Just as a word of advice, pull the speedometer and see if the odometer drive gear has been replaced yet. If it hasn't, I would suggest doing it now and save yourself the headache later. If you see the brown gear in the pics here: http://www.klaindustries.net/gearinstr/gear-instr-1.htm you'll want to order a new gear and install it.
One of those "while you're in there" things...
