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A fellow owner here in the states wants to change his 1991 Si KMH speedometer to a MPH scale.

The speedometer in the Si is not the same as in the Ford cars.


1st possible approach -

It is likely the speedometer, which is electronic and fed with a two wire VSS signal, was sourced from another automobile. Does anyone happen to know what that car would be? Thinking they might have a USA version if the car was imported here

2nd possible approach -

Has anyone had a positive personal experience getting a new gauge face made for a gauge?

I have personally taken North Hollywood Speedometer completely off my list of shops due to a total lack of response several years ago. West Valley Instruments finally completed my project but failed to deliver a matching gauge face, by not following my very clear instructions or examples.




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Last edited by lf-tp2511
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Interesting approach. Thanks. We are just throwing everything at the wall to see what sticks at this point.

i’m assuming you’re referencing an electronic device that alters the VSS signal?

this is not the currently common three wire Hall effect VSS signal, but the earlier 2 wire design that created a sine wave. I’m thinking that might complicate actually finding a correction device for that earlier design?



I'm sure any gauge shop can make a new face for the gauge. It's the same as the speedo in a some Ferrari's. The sending unit is also used in some Ferrari's and Alfa's of the same period. You can try Palo Alto Speedometer. They have an excellent reputation but whenever I've called them, they're backed-up and can't handle my job for months. I've had better luck with North Hollywood, which isn't meant as a glowing recommendation. The work is excellent but takes forever. I tried a shop in New Mexico but it was even worse. I think the name was MoMa Manufacturing.

If you find a sending unit from a US model, it's likely the same as the European version. The speedo face will be different, not the sending unit.

If the car owner just wants the speedo to register in MPH, the easiest way is to use an Autometer GPS sending unit. The connections to the Si gauge are easy and you can calibrate it so KPH becomes MPH.

I know this works because I have an Si speedo in my Pantera. I had North Hollywood Speedometer put the workings from an Si speedo into my OEM Pantera speedo. At first I used an Si sending unit but I switched to the Autometer GPS sender as it's accurate to 3 ft! The part # is 5289 and it's $230 at Summit.

Last edited by davidnunn

I was thinking about what Julian suggested and he's right; you could use a VSS correction device. Dakota Digital used to make one with part # SGi-5e. It was just for VSS signal in - VSS signal out. The new model is an SGi-100BT and has many more functions. I considered one a few years ago, because I wanted to use my Si sending unit (8 pulse) with my EZ Electric power steering (4 pulse). At the time, I did confirm the Si sending unit was compatible. I'm sure other companies make similar devices.

Of course, your friend could also just learn the metric system and leave the Si alone!

Simplest thing to do is get an reprint from Hall with the white letters, Pantera 200mph face and just replace it. It probably is an absolute replacement -except- the odometer and tripometer windows will have to be extended (since the odo is now 6 digits, and the tripometer on the electronic is a different mechanism and the spacing of the digits is wider...). Using a diamond file and widening the windows in the aluminum face is not hard at all. I did this having fun converting a Goose speedo to electronic (see attached video).

Or, get a swap kit from a Ferrari and punch more holes for the idiot lights.

  Of course, only changing the face means that the Odo will still count KM, and there is no practical way to separate the motor for the ODO from the Speedo drive (on Veglia electronic speedometers that this one certainly uses). So then yes, the electronic "speedometer calibrator" David suggests will work fine, even if the working range for the speedo is really small...! A lot of people sell something that should work, seems to be a big market for motorcycles (and will glue directly in and work with Veglia). And can be used to calibrate tire size changes at the same time.

I'd be interested too in getting a custom dial made, I'm sure you could (printed on vinyl (Heiler prints on plastic substrate, or 'Aufkleber' versions as well). I think there is a place in Australia and another in the southern US that may also...My experience with N. Hollywood was as yours, a quote from PA to create a new silkscreen or pad print (whichever) was very pricey...). But it seems that some people will just use electronic print directly.  You would need to start with a scan of the dial you have now, and someone will first create new artwork with 100 at 12:00, work to get the colors right, etc--Lee

(ps, finally for my 'no reason to finish it but Covid pins me at home' Goose speedo, I decided against a later Electronic Veglia (as in the video...its just a few millimeters deeper than the can itself) and when I instead used a generic programmable speedometer (based on a stepper motor for the speedo and LCD display for the Odo that first where the tripometer is...). When I have absolutely nothing to do, I'll probably finish it, then put in on the shelf with my stepper motor Tach...)



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new guts for an old face
Last edited by leea

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