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Tic Toc Tach Accuracy

dfrazz

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After repairing my Tic Toc Tach, I wanted to see just how accurate it is so I used and engine tester to see. Anyone surprised?

 
The original Tic-Toc-Tach had resistors and capacitors which had +/- 20% tolerance and old style germanium junction transistors and volt meter (calibrated to read RPM) of the moving coil design and a +/- 10% accuracy......which accounts for the marginal overall accuracy. The new upgrades that use IC chips are much better but subject to the same meter design......JMO......
BOB RENTON
 
Keep in mind...
The OE tic/toc tach is not compatible with any type of electronic ignition system, only works correct with the analog OE ignition system.
The tach may register RPMs but it will not be accurate.

Just my $0.02... :thumbsup:
 
In my experience the Tic Toc Tac in my '70 GTX was actually very close to being correct until hitting the 5,000 RPM mark....then it went on it's own journey. :lol:

Yes....seat of the pants experience side-by-side with another known tachometer. :thumbsup:
 
Contact rt-eng.com and see if their tach conversion module will work. it has a built-in calibration at 1,000 and 4,000 RPM.
 
Keep in mind...
The OE tic/toc tach is not compatible with any type of electronic ignition system, only works correct with the analog OE ignition system.
The tach may register RPMs but it will not be accurate.

Just my $0.02... :thumbsup:
Mine doesn’t like my DC ignition and sweeps high under load. I know I need to upgrade the tach board but forgot who does them? Maybe RTS or @Skatpak
 
Mine doesn’t like my DC ignition and sweeps high under load. I know I need to upgrade the tach board but forgot who does them? Maybe RTS or @Skatpak
Good question..
In my 70RR with electronic ignition I installed a tach from Red Line Guages, basically a VDO inside but with a rescreened front to match the other Mopar guages. The VDO works fine with MSD and Mopar ignitions. Note that Red Line is local to me in SoCal and they do the custom guage works for many of the high end builders like Pure Vision, Julias Restorations. IMHO.. The best guys for guages, if U contact them talk to Shannon. Here is a link to their site.



Just my $0.02... :thumbsup:
 
Good question..
In my 70RR with electronic ignition I installed a tach from Red Line Guages, basically a VDO inside but with a rescreened front to match the other Mopar guages. The VDO works fine with MSD and Mopar ignitions. Note that Red Line is local to me in SoCal and they do the custom guage works for many of the high end builders like Pure Vision, Julias Restorations. IMHO.. The best guys for guages, if U contact them talk to Shannon. Here is a link to their site.

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Just my $0.02... :thumbsup:
Thanks brother
 
Contact rt-eng.com and see if their tach conversion module will work. it has a built-in calibration at 1,000 and 4,000 RPM.
I had my tach repaired by Redline and am running a Mopar electronic ignition. I didn't expect it to be exact, its mostly for the cool factor.
 
Pure Vision Design and Steve Strope are very creative...
Back in 2013 for SEMA they did a 1968 Charger RT project that appeared in Mopar Muscle, Hot Rod, American Muscle Cars magazine. One creative thing that Pure Vision did along with Red Line Guages, they designed a ralley dash and they positioned the tach and speedometer guages centered over the steering column. Next they mounted the fuel and temp guages on the left and the oil pressure and volt meter guages on the right for a balanced, symetrical appearance for the ralley dash. Nice touch but keeping with the Mopar legacy. Below are a couple of pictures.

Just my $0.02... :thumbsup:

chargerready_66_.jpg


SS_CP.png
 
I didn't expect it to be exact, its mostly for the cool factor.
That is the correct attitude for these parts. I don't think they were ever accurate - flukey if they were given the technology of the day. :thumbsup:
 
I had a new board put in the console tac of my 66 that would handle points or electronic ignition. It had a calibration feature which I used to tune it to match my tach on the steering column exactly. It’s a bit of a chore but works as promised.

Only problem is you’re looking down on the tach in the console at a vertical angle which casts the needle on a lower part of the scale and makes it look like it’s reading low. And on the high side of the rpm scale it would make it read higher than my reference tach. I decided that although the working console tach is cool, that I was better off to leave my steering column tach in too.
 
That is the correct attitude for these parts. I don't think they were ever accurate - flukey if they were given the technology of the day. :thumbsup:
I agree.. :)
For my 70RR, I look at the guages frequently but more for their general average readings..
Such as the temp guage, what is its normal temp reading.. Is it climbing?
Same with the oil pressure.. Normal readings.. Is it low or high?
If I wanted more accurate, specifc readings I would install a high grade of aftermarket guages.

Just my $0.02... :thumbsup:
 
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