ramona300
True Classic
The original tacho was 0 to 8000 rpm the same as most of these cheap Chinese tachos. There are no stops on the tacho face, it's a mechanical stop inside. The needle is just a push fit so it's just a matter of holding the bit inside on the stop with a finger and putting the needle on zero. The signal goes to the tacho from the ECU. The ECU gets it's signal from the 36-1 wheel on the crankshaft so there are no mechanical errors like the distributor gets from the gears. It's about as accurate as you can get!I did something similar with a vintage motorcycle. However in that case it was a matter of swapping one mechanical device for another one. But there was one issue with it....
Does using the original Fiat tach gauge face have the correct read out to match the new tach guts? I mean in terms of the numbering and spacing being the same as the new tach's sweep and values? Or to put it in other words, is it accurate now?
In this video the problem with the car's original tacho is obvious. On top of the dash in the middle is a similar 52mm tacho that I have now removed. I also removed the change light. On the tablet I have re-arranged the dials so the tacho is now on the top right and I have made the dial about 120mm diameter. I set the parameters so that as the engine passes 7500 the dial will go red. This will work like the change light and should be visible out of the corner of my eye.