Jump to content

WhiteV

Recommended Posts

Well, it won't read right.  Will read 50% high due to having 50% more cylinders and thus 50% more sparks per revolution....

There are allegedly ways of recalibrating (google is your friend) but I didn't have much joy with them in spite of trying hard.  You may well be cleverer at electronics than me though - many people are.

I currently have a late saloon one (2500S?) which is the easiest to wire in.  Earlier ones from the PI are also possible but require slightly more wiring effort.  Neither are a cosmetic match (I don't much care fortunately, but you might) and swapping the needle and dial are not very easy either due to different sweep angle and balancing methods.

If you have electronic ignition, this can also cause triggering problems on the earlier 'wire through' types (PI etc) although the later 'wire to' are pretty tolerant.

Not sure if any GT6 had an electric tacho?  Late saloon one is the best bet.

Cheers

Nick

Link to comment
Share on other sites

I've not seen inside an electronic Triumph tacho so I cannot be sure, but the Ford Cortina Mk1 GT unit had a pot inside to adjust the charge pump circuit.
If you have an audio signal generator it would be possible to adjust / modify the unit if it meets the Ford unit design.
The circuit is a simple RC time constant driving a moving coil meter.

There are companies that re-furb / overhaul these units, you could try them.

Simon

Link to comment
Share on other sites

Hi -- thanks for the diagram ---oh by the way i know you guys indicate 4 pot and 6 pot are different --- recently on ebay one was advertised listing both engined cars?
i trust the eventual buyer found it of some use?  --- kind regards

Link to comment
Share on other sites

Note that circuit diagram is for the early type tacho  - the 'wire through' one as used on the PI etc.  The Spitfire1500/Dolomite/2500S/Stag ones with the 'wire to' configuration is mostly an intergrated circuit. I have never seen a circuit diagram for that one (and I have looked) and have never been able to identify the chip properly.

No Triumph tacho I've seen is switchable between 4/6/8 cylinders and as I said earlier, although there are 'guides to alterating/calibration on the net, none of them have worked for me.

Smiths did also make after-market tachos some of which were switcheable between 4/6/8 cyl.

Nick

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...