Calibrating speedo

[james3004]

I'm trying to calibrate my etb speedo, it's wired up to the electronic speed sensor in the mt75 box.

Currently it's set at 4000 pulses but appears to read roughly twice as fast as it should!

Does anyone know what the ratio is for the gearbox speed sensor is and how many pulses per rev the sensor does?

[alga]

I've used a Hall sensor type speedo sender from some Ford, probably a Mondeo. The sender gives 8 pulses per revolution, it's mated to the speedo cable port on a Type 9.

The speedometer cables used to be calibrated to 1000 revs per mile or some metric approximations. I just set my speedo to 5000 pulses per km (ie assuming 625 revs per km or 1006 revs per mile), and my speedometer reads well enough, without a significant discrepancy to the phone GPS.

Are you using the gearbox with the final drive that came from the same car?

Hope this helps!

[james3004]

Originally Posted by alga

Are you using the gearbox with the final drive that came from the same car?

Yeah, all from a ford sierra think I will try Setting to 8000 and see what happens