Electronic Tacho Recalibration

[SteveA]

So in the GT6 accident last year the electronic tacho, from a Triumph 2500s, died and I havn't been able to find another donor six cylinder tacho since. I have heard mention that you can re-calibrate a four cylinder tacho to six cylinder, does anyone have any pointers on how to do this?

My thinking was that it would be much easier to get a donor tacho from a later Spitfire or Dolomite and convert that for my needs.

[PeteClan]

What's the damage to the original?  Could be worth contacting Speed Cables as I've used them in the past to both repair and re-calibrate electronic tachos.

 

Pete Richards

[SteveA]

There is probably a fault somewhere on the circuit board becasue as soon as supply power is put on to it, the needle stikes over to maximum and stays there. I tried changing circuit boards with the other tacho I had, but the fault follows the circuit board. The second tacho is slow to respond and does not show a true reading, even at a steady speed.

[CHRIS211083]

Call chic doig sports cars. He will also know how or if you can convert them over.

 

Chris.

[GT6 Nick]

Both my Herald and GT6 have converted tachometers. A gauge shop here in Oz uses the internals from an aftermarket tachometer, with the Smiths' gauge face and needle. The scales are similar, but not perfect - comparing my Herald's converted tach to an unmolested electronic one showed that the new one reads 6000rpm when the engine's actually doing about 5700. I figure that's close enough.

 

N

[Nick Jones]

Steve,

 

I found my extra one recently (amazing what turns up when you you are clearing up ready to move!).  It's the later 2500S one, voltage sensing.

 

Nick