Speedo Fix for Transaxle Transplant

[MD]

Darryl

I haven't and I don't know what others have done. When I was working on this years ago, we used signal generators and CRO's to analyse the original signal character from the Veglia sender and then compare that to the nature of the Jaeger sender and then create a circuit to make the translation. As I said earlier, this did work but not as reliabily I as necessary. What I can say is that pulse nature, pulse rate and voltage values (3) are all different that's why they are incompatible.

[GTVeloce]

MD, Thanks for this info. I have just bought the Dakota unit you mentioned and have been looking through the destruction manual. Do you remember which application number is relevant? This is the last issue remaining for me and I am keen to finish it!
Cheers

[Al Campbell]

The Jaycar kit is essentially designed to change pulse rates for when you've changed tyre sizes or diff ratios and your speedo is now in error because it is getting pulses at the wrong speed. Although it does have a "learning" mode when it tries to work out what sort of transducers it is connected to.

I've bought one, but it's sitting in the workshop waiting for assembly (I got my first speed camera flash in the ALFA last week).

MD do you have any experience with the Jaycar kit and Jaeger sensors?

[MD]

Yep tried this cheap angle for the Jaeger sender to Veglia speedo conversion but it doesn't work ( or I couldn't make it work).
The thing is whether you use the VDO solution or the Dakota one, they both provide for  speed correction as a consequence of having to provide for gearing that different cars have. It is almost impossible to get a commercial speedo in a car to be 100% accurate as simply driving the car on a very hot surface in summer will cause your tyres to be more inflated than standard and provide ever so slightly taller gearing. Soon as you change tyre profiles from the original equipment, it's out of whack. So it is about being near enough good engough. Absolutes are out of the question.

In my own case, my speedo is 4% over reading @ 100 km/h. This means an actual speed of 96 while displaying 100. This is good because it gives me a small margin of safety against speed cameras, particularly if other than myself drives the car and is relying on the displayed speed.

Majority of cars over read to flatter the driver.Some more so than others.

Good luck with it Al. Let's know either way please if you don't mind.

[MD]

GTVeloce (and anyone else contemplating using the Dakota unit)

You can get a lot of information about this issue including circuits here:-

http://alfagtv6.com/phpBB3/viewtopic.php?t=91