Calibrating VDO/Audi speedometer to compensate for
different tire diameter
Wed, 31 Jan 2001 14:39:02 -0500
oh ya, about calibrating the speedo, I don't see anything about adjustment
in my 5k Bbentley. But I think the speedo sensor just outputs a 0-5V signal
to indicate speed. So you could adjust this by putting a simple circuit in
between the sensor and speedo. To reduce the voltage, you can simply use a
voltage divider [just 2 resistors in series], and to increase the voltage,
you can use an op-amp w/ a linear gain. The circuits would be real easy to
build, but setting it up and calibrating would be the hard part.
At 01:49 PM 1/31/2001 , you wrote:
>lowering springs help a lot. of course with the gearing in that car,
>taller tires shouldn't be a problem. Sorry, I have no idea how to
>recal. the speedo though...
>"Mark W. Byrum, Jr." wrote:
> > Can VDO/Audi speedometers be calibrated to compensate for different
> > (as opposed to stock) tire diameter? My '89 80q seems to have a lot
> > of room around the tires in the wheel wells; if a calibration could be
> > done, somewhat larger tires might be installed.
> > Just a thought.
> > TIA,
> > Mark