electric speedometer?

[como]

The speedo cable in my 85 is going out, and since I've got the whole car torn apart I thought it might be a good time to replace it- although I'd rather replace it with an electronic unit somehow.
I'd like to keep it looking stock, so I figured I'd ask here and see if anyone knows of any sort of retrofit kit where I could use the stock guage.

If not, what are my other options?

[328FTW]

Been thinking the exact same thing I have broken 3 cables in my car so far and can't figure out why I'm beginning to suspect the plastic drive gear is broken and whipping the cable.

[Jackstand Queen]

Hmmm . . . . an electronic speedometer . . . . ?

They are extremely accurate, if it was calibrated correctly and it said you were doing 150 MPH, you'd be doing One Fifty.

Our mechanical piano wire driven speedometers are horribly inaccurate at high speeds. A reading of 160 MPH could actually reflect going 130. The inside of a speedo uses a friction co-efficient dependant gadget, that will give jerky or false readings if its dirty, or the lubrication has dried up.

The electronic speedometer would have to be programable. You could'nt put in a honda, or mazda speedometer and expect it to work. The gear ratios of the differential would change the speedometer reading if the meter reads from the tranny.

A lot of electronic speedometers use a small AC current generator attached to the tranny where the mechanical speedometer usually attaches to.

If you had a working cruise control, it wouldn't work after putting in an electronic speedometer.

[como]

well, I certainly don't have cruise control- nor would I want it (Bought an old car because stuff is simpler )

I kinda figured a retrofit kit would just bolt onto the tranny where the cable came out, generate a little electricity, and then send out a signal- I could use my gps to calibrate it pretty well, but I'd have to find one to install and calibrate first- which is apparently not as easy as I had thought!

[328FTW]

I have a celica cluster with a sender and receiver from my mk1.5 swap I'll take a look at that and see if it is even remotely close

[MR JAS]

Originally Posted by 328FTW

I have a celica cluster with a sender and receiver from my mk1.5 swap I'll take a look at that and see if it is even remotely close

if you can fit it but its the wrong drive ratio i.e. inaccurate
you can buy a kit at jaycar that is made to adjust electric speedos to be accurate again if you change wheel size etc
i think its like $10

[328FTW]

Originally Posted by MR JAS

if you can fit it but its the wrong drive ratio i.e. inaccurate
you can buy a kit at jaycar that is made to adjust electric speedos to be accurate again if you change wheel size etc
i think its like $10

There are some tricks the beams guys use as well that I saw over on the celica forums. Don't know if they work or if the electronic sender is easily adapted. We will see I need a speedo for my warrant as of yesterday.

[como]

If it's as simple as a voltage converter I could adapt it (hobby electronics) to show at least a close to accurate number.
I'd rather just buy a universal adapter type thing to use the stock guage, though. Nothing like this exists?

[Jackstand Queen]

The speedo might work on a pulses per second basis, rather than spinning faster generates more voltage. The current on speedo AC generators is very low.

[traintech86]

i read this thread once before and then when i went cruising and i noticed that the speedo jumps around when i am going slower then 25. i am military so 25 is the required speed on my base and they are a bit anal about it. i hope this electric idea would fix it.

[como]

I want the electric more because I don't want to have to reinstall that **** cable

So nobody knows of an actual retrofit?

[328FTW]

Originally Posted by como

I want the electric more because I don't want to have to reinstall that **** cable

So nobody knows of an actual retrofit?

I'm looking at it but its more complicated than it sounds, your odometer runs off the cable as well and I would like to keep that to.

Edit: I've done my cable like 3 times already its starting to drive me insane.

[Jackstand Queen]

Try finding a new speedo cable the exact needed length. Its around 11 feet long or so. An uncommon size.

Traintech: if your speedo is doing the herky jerky at low speeds, it needs to be pulled, cleaned off, re-lubed and re-installed. Sometimes you have to do this whole procedure more than once to get it cleaned and lubed.

[328FTW]

I lubed my cable and speedo drive several times and still had bouncing which leads me to a broken drive gear since it has only done it since the manual conversion.

[como]

Since she's just about an antique I don't much care for the odometer, but seeing as how its just a spinny thing I'd think someone would have created a bolt on electronic unit- just took 12v on either end and runs a wire between the points to vary the speed of a tiny electric motor that plugs into the back of the speedo, and a sensor on the tranny side.

I mean, matching the speed couldn't be too hard. Anyone know how fast this little thing spins, roughly? I'll look into what it would take to build such a device. (hobby electronics are fun)

[mr2tim]

Old motorcycle trick I used is to lube the cable was to fill a baggy w oil stick the end of the cable in it, tape off the baggy to the cable housing, and hang the baggy from a high point and let the oil flow thru the cable.

The used cable lasted 3 weeks then broke again....

So much for old tricks...

[Jackstand Queen]

An electronic speedo could also run by reading a magnet attached to a drive shaft, or axle.

Has anyone done a deep scan google for aftermarket "universal type" electronic speedos?

[MR JAS]

Originally Posted by 328FTW

I lubed my cable and speedo drive several times and still had bouncing which leads me to a broken drive gear since it has only done it since the manual conversion.

is it still doing that since the gearbox change

[328FTW]

Originally Posted by MR JAS

is it still doing that since the gearbox change

It had the same cable for around 20 years and then when I changed to the manual box suddenly it starts snapping cables like crazy. May be related may not but it normally breaks at the base right near where it screws into the box, cable whip is normal on an open gearbox on corners to a certain extent but not the weird whipping I get, this time I'm pulling the drive gear out of the box and either replacing it with another or looking at making up an electronic sender. For now I'm driving my mums old honda with dual carbs and 20hp YEEEEEAAAAAAAAAA

[mr3]

This may sound stupid, ok really stupid, but what about a bicycle speedometer? They have electronic ones so no need for wires and they are fairly cheap. If you could find some way of mounting it and calibrating it you would be set. I remember people talking about them for their 110cc pocketbikes and they said they were very accurate and the top speed goes up pretty high. Like I said, it was a stupid idea but if you could make it work then you can have a speedometer setup for pretty cheap. One major problem is that they use watch batteries so you'd have to change them every few months or whatever.

They work with a magnet attached to the rotating object then when it passes the sensor it sends the signal to the "gauge" so you can tell your speed.

PS they only cost about $50