[Mk2] [NA] ANother Speed Converter Problem

[barico]

Hello everyone. I have an Automatic G Limited with a KPH Speedo, 1993 rev2.

I have a speed converter chip I wish to install and need to locate the speed sensor cable running off the gearbox. Now I have read that it should be 3 pin and under the distributor but it doesnt help much because I'm still not sure where it is. Also the people who gave this location all have the manual transmission if that makes a difference.

I found what I thought might be it but dont want to go messing about chopping up wires if its the wrong one.

Also I had an idea. I am cutting the speed sensor in the engine bay, Is there any reason I cant cut the wire (If i can find it) behind the dash instead and fir the converter in there?


I was wondering if this is it?

[iblis]

This doesn't really answer your question, but before you start cutting, are you aware that it's going to screw up your gear changes? The auto box changes gear based on that signal, and that chip is going to adjust the signal by 5/8. Which means if it was changing from 1st to 2nd at 40kmh before, it will change at 40mph after.

[Tiny]

thats why you have to do it at the dash as the Dash display is the end user and the only thing in the dash that uses it if you do it at the speed sensor location as shown in your pic your just asking for problems

[iblis]

The speedo pulse goes from the box to the instrument cluster, and from there to the ECU.

The gear change / power steering switch off / speed restricting is done by the ECU. The only way to stop it affecting the gear change is not to modify the pulse to the ECU. However, that will also prevent it from delimiting.

So if the aim is purely to convert the display on the speedo to be MPH, and not remove the 112.5mph speed restriction, then it is probably doable behind the dash. However, it would be a lot simpler to get a UK spec speedo and transplant it into the JDM instrument cluster (which also will display MPH but not remove the speed restriction).

If you want to keep your gear changes correct and your power steering turning off at the correct time (80kph not 80mph), and you want to remove the speed restriction, you will need a clamping delimiter, such as that from twosrus.co.uk (in fact, those particular delimiters were originally designed to overcome the problem of delimiting an auto JDM car). They cap the reported speed to the ECU instead of altering it 5/8.

[barico]

Thanks for the ideas. It is making me think I should have just got a 110mph face instead. I rarely drive it past 110mph anyway, the g ltd auto doesn't have much go at that speed anyway.