Speedometer upgrade, No more broken cables or angle drives Options

[ClayPerrine]

I found something online that I wanted to try:



I bought one and wired it to my factory 911 speedometer.

I wired it like this:



The white wires are from a 12v DC transformer, used to bench test it. The Positive is on the left, and the negative is on the right. The Autometer module is wired to the same positive and negative lugs, and the purple wire from the Autometer is connected to the speedo input. The other speedo input is jumped to ground.

Running the calibration procedure in a bench test, found here , I was able to get the speedo to read exactly 80 mph, and the odometer was working too.

The next step is to test it in a vehicle.

The heavy wires from the positive and negative go to an old cigarette lighter plug that I will use to test it in my truck, comparing the output with the truck's speedo, and my android app "gps speedometer".

If everything works as I expect, I can remove the speedo cable and angle drive from my car. I will probably plug the speedo output in the gearbox to prevent any gear oil leaks.

I will update this when I run the second test.



I will keep you updated on the results.

[Madswede]

I've outrun the GPS speedo app on my iPhone. (IMG:style_emoticons/default/w00t.gif)

But in reality, that's probably just a software programming issue with the timing of it pinging the satellite(s). I mean, my car is quick, but it shouldn't be THAT noticeable.

[mikesmith]

I've outrun the GPS speedo app on my iPhone. (IMG:style_emoticons/default/w00t.gif)

But in reality, that's probably just a software programming issue with the timing of it pinging the satellite(s). I mean, my car is quick, but it shouldn't be THAT noticeable.

GPS doesn't work like that. The receiver is passive, it doesn't "ping" the satellites, it's just listening to them talk.

The app may have some silly restrictions in it about how high a speed it will display; might be something as simple as UI layout, or some stupid law about encouraging speeding like the one that prevents the roadside "this is your speed" display from showing more than ~15mph over.