pfc vehicle speed incorrect
 

Hi!
I have a 1992 fd3s with a apexi pfc
On the commander it shows my vehicle speed is about double than what my speedometer is showing. Can anyone help me understand why it is doubleing my speedo and how to fix this? :-)

Best regards Frank :-D

I have the same issue.. When I hit 100km/h+ there is a slight difference between the PFC and my speedo.

When i Am at 100kp/h my commander shows around 200+kp/h

little info that I found.
https://www.rx7club.com/power-fc-for...needed-166439/
There IS a Power FC forum so grab some Coffee,gain some posts and knock yourself out with some threads!!
I don't mean that sarcastically.I Did that when I first got here and Hell,..I am a sponge.
I can't dance but I can wrench an FC..lol!

By the way if you read that thread it mentions FD.

Stock wheels and tire size?

Yes, all original wheel size.
There is something fishy about the speed on my commander... Its dobling my actual speed.. Anyone???
And sometimes my speedometer is jumping up and down like 10-20km/h

This is pretty anoying! Help needed! :)

Frank.
As I mentioned there IS a Power FC forum section.
If you gain posts and put up your question there you may get more definitive answers.
This NEW TECH section is a mixed bag of problems and cars that usually stock,so it is not always the best place to post questions on highly modified cars.

And I was responding to Senna88..he indicated a much smaller differential.

Running bigger wheels & tires. But wouldn't the speedo & PFC still be both wrong in that case?