Tacho adjustement
01-25-2016, 06:34 PM
#1
Pro
Thread Starter
Tacho adjustement
Can you adjust the tacho? Mine shows approx. 150 RMP higher than Rogue logger as well as other meter that takes signal from coil. It is pretty annoying when car is idling but makes no difference at higher revs, at least for me. I'll have the instrument cluster removed tomorrow, it would be a good time to tackle this problem. Any suggestions?
01-27-2016, 03:06 PM
#3
Rennlist Member
I've never played with the pots on the tach, but will check them out on my bench simulator and report back. If they don't help, you could always adjust the tachometer with a variation of my speedometer calibrator, if you were up for a project and really wanted an accurate rpm.
http://members.rennlist.com/tom86951...r%20Page1.html
https://rennlist.com/forums/944-turb...dobooster.html
http://members.rennlist.com/tom86951...r%20Page1.html
https://rennlist.com/forums/944-turb...dobooster.html
01-27-2016, 04:48 PM
#4
Pro
Thread Starter
Tom thanks for the links, I've already read these posts some time ago. Awesome work, I wish I have your skills... Anyway, my speedo shows pretty much accurate speed, 3 - 5 km/h different than GPS reading - I consider it accurate enough. Reading your post above I presume that I can use the same PCB to adjust RPM the same way I can adjust speed? Much easier way would be to adjust the pots on the tachometer itself if they are there for this purpose. Let me know if you are able to find something out if you have spare minute.
01-27-2016, 08:42 PM
#5
Rennlist Member
Tom thanks for the links, I've already read these posts some time ago. Awesome work, I wish I have your skills... Anyway, my speedo shows pretty much accurate speed, 3 - 5 km/h different than GPS reading - I consider it accurate enough. Reading your post above I presume that I can use the same PCB to adjust RPM the same way I can adjust speed? Much easier way would be to adjust the pots on the tachometer itself if they are there for this purpose. Let me know if you are able to find something out if you have spare minute.
The tachometer signal is a sharp square 12v pulse, so the Schmitt Trigger chip on that board is probably overkill, but if would serve as a nice signal buffer and clip the 12v signal to something the cpu input can handle, so yeah that hardware would probably work just fine without change, although I'd want to test first. I have a more advanced version now that does away with the arduino and also controls the boost gauge -- search speedobooster -- that PCB is available at OSH Park for free too, though that software is more complex. Happy to help if you decide to build one though.
01-28-2016, 09:40 AM
#6
Pro
Thread Starter
I may actually build one as I'm running out of projects slowly... Car is perfectly restored, everything works as expected, what next??? LOL
Let us know if you were able to adjust tacho through pots.
Let us know if you were able to adjust tacho through pots.
01-28-2016, 10:48 AM
#7
How many hp is that? What's the top speed? 
Will do, I just have fire up my cluster test rig... this thing:
ICS video - YouTube
The tachometer signal is a sharp square 12v pulse, so the Schmitt Trigger chip on that board is probably overkill, but if would serve as a nice signal buffer and clip the 12v signal to something the cpu input can handle, so yeah that hardware would probably work just fine without change, although I'd want to test first. I have a more advanced version now that does away with the arduino and also controls the boost gauge -- search speedobooster -- that PCB is available at OSH Park for free too, though that software is more complex. Happy to help if you decide to build one though.
ICS video - YouTube
The tachometer signal is a sharp square 12v pulse, so the Schmitt Trigger chip on that board is probably overkill, but if would serve as a nice signal buffer and clip the 12v signal to something the cpu input can handle, so yeah that hardware would probably work just fine without change, although I'd want to test first. I have a more advanced version now that does away with the arduino and also controls the boost gauge -- search speedobooster -- that PCB is available at OSH Park for free too, though that software is more complex. Happy to help if you decide to build one though.