Cable Driven Speedo Corrector +16.5% Ratio
Ratio Box (plus 16.5%) to suit cable driven speedometers with M22 metric drive
Cable Driven Speedometer - Speedometer Correction
Speedometer correction is required for many reasons, larger tyres would be the most common off road vehicle enhancement requiring the use of one of these units. Differential ratios may also be changed to enhance the performance of four wheel drive vehicles, this also changes the calibration of the vehicles speedometer.
The most accurate way to determine the correction box to suit your requirements is to use a GPS unit and compare readings to your speedo. Drive at 60 km/h using the GPS record the speedometer reading. Repeat this step at 80 km/h and 100 km/h.
To calculate the percentage required use the equation;
|GPS Speed||divided by||Speedometer Reading||multiplied by||100||subtract||100||equals||Ratio|
eg. GPS reads 60 km/h and the speedometer reads 52km/h. The equation would be 60/52 x 100 - 100 = 15.38
We always recommend having a safety factor, so with the above example we would recommend a +16.5% unit
Marks 4WD Adaptors stock ratio boxes to suit the most common ratio changes, however should you need a custom ratio please phone our sales staff on 03 9552 6555 with your speedometer reading compared to GPS reading at 60 km/h, 80km/h and 100km/h and we can create a custom ratio.
- Ratio box plus + 16.5% ratio
- All models running M22 thread and round drive speedo cable
Part No. MFK1468B