Digi Dash Calibrating

[Spikehaus]

Originally Posted by davidimurray

Have you changed the tyre circumference setting in the dash to calibrate the speed? See - http://www.digitalspeedos.co.uk/RX2n.pdfb page 13 section 4-7. You will need to half or double the value as appropriate (too early on a monday morning for me to work it out ) to get the correct speed reading.

I am working on my speedo calibration at the moment, but would like to check my calculations. I am using an Koso RX2n with an optical sensor, but will refer to the trigger signal as magnets. I have installed a single bolt on the side of the input prop shaft flange plate.

Tyres are 195/50/R15 with a circumference of 1810 mm
LSD Diff is a: 3.62:1 from a Sierra Xr4x4 2.8 V6

So,

1810 mm divide by 3.62 diff turns per 1 full rotation of wheels =500 mm / 1 magnets - Summary Input 2000 mm circumference with 4 Nr Magnets

Am I on the right track with this?

[rich]

What gearbox you using? My koso dash came with a sensor that fitted directly into the type 9 mechanical speedo drive, trip out with the satnav, set up 4mph over and IVA man happy!

[Spikehaus]

Originally Posted by rich

What gearbox you using? My koso dash came with a sensor that fitted directly into the type 9 mechanical speedo drive, trip out with the satnav, set up 4mph over and IVA man happy!

I have a Ford Type 9 Close Ratio Box, it does not have a speedo gear in it, just orginally some form of electronic speedo drive unit that does not work. I have used the optical sensor that came with the unit.