Module 4 - Speedo Transducer

Module 6 Build:
<11th April 2006>

To sort out the speedometer i needed to work out the pulse value to enter into the gauge.
To do this i needed to work out the circumference of the wheel then calculate how many times this will go into 1 mile (in inches). Then multiply that by the number of pulses the sensor would read per revolution. Once i have that its just a case of switching on the ignition with the button pressed on the front of the gauge, then pressing the button continually to enter the calculated value.


This has been a real pain. To get the signal there is a feed off the ECU that i needed to connect to the Westfield loom. This then runs into the back of the Tachometer.
After starting the engine there was no reading on the gauge. The Webcon kit provided a 1K Ohm resitor patch that fits to both live and signal cables. This got the gauge showing a value but the value was way to high. It was showing an idle of 3k rpm and a slight blip on the throttle took it to 8k rpm. There is a potentiometer screw on the back of the gauge which allows adjustments and this seemed to work quite well but without an idea of the actual engine speed this adjustment is too dangerous and so i left it alone until i could accurately assess the engine speed.

<23rd April 2006>
Sorted the Tacho problem, due to the wasted spark system the tacho needs to be set to 6 cylinders. I made the switch and it seems to be reading perfectly!