For speed meter device installation, it usually need to calculate a revised value of the tyre diameter. By installing speed meter device, we can display engine RPM, vehicle speed, vehicle acceleration timing and stopwatch features.
The revised value of tyre diameter is needed for setting up program mode of the speed meter usually after set the RPM induction output, vehicle speed induction output, cylinder number setting and speed limiter setting. The calculation can be done by dividing Changed Tyre Diameter into Stock Tyre Diameter, as seen in the Skyline GTR Tyre example (picture), the revised value for the vehicle will be 1.03 (652/632).
How to Calculate a Revised Value of Tyre Diameter for Speed Meter Installation continued »