Speedometer correction with tuner / programmer?

Texas Bronco

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Can a tuner calibrate for changing tire sizes? I'm used to obd1 cars.
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L8apex

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A tuner should definitely be able to. But I'm hoping someone that has Mike Levine's ear on twitter can ask if this feature is available through the cluster?
 

Rick Astley

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Can a tuner calibrate for changing tire sizes? I'm used to obd1 cars.
My understanding is that with speed sensors on the hub instead of rotating mass, that modern cars are self-correcting ECU's now. There are too many other metrics that rely on vehicle speed such as stability control to have to manually adjust them anymore.

You kids and your fancy OBDI! I have to have speedo gears made for the transmission housing to get my classics adjusted for different wheel sizes. (Ultimately that being a waste of time, I just eyeball it or disconnect the speedo entirely)
 

Spooled

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Making it adjustable on the dash would be a liability issue.

Now if they could somehow tie it to GPS and auto correct the speedometer that way... that would be cool.
 

HoosierDaddy

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Third thread, same question.

Ford systems the I am familiar with derive the vehicle speed from the braking system, which monitors the tires rotation all the time. The computer needs to know how many "Revolutions per Mile" the tire has/ It is listed under the specs for any given tire size. Check the manufactirers web site.
In the ABS system , there is an parameter that can be changed for the tires RPM(mile).
Ford techs can do it in a few minutes.
I have no idea about tuners etc.
 

rtaylor

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Can a tuner calibrate for changing tire sizes? I'm used to obd1 cars.
Yes. If you order a custom tune, you can specify the diff ratio and tire size. Generic tuner products usually support this as well. You can also take it to a Ford dealer and have them change it (for a fee).
 
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