I get a lot of questions about speedometers and VSS signal recalibrators such as the Dallas Mustang Speedcal or the FRPP Speedometer Recalibrator, and how the switches on those units should be set.
I did a lot of research on the internet, and have created a couple of calculators that you can use to figure this stuff out.
Since the device recalibrates the VSS signal, you really need to know what the VSS signal rates are in order to calculate the switch settings. As a result, I used VSS rates as the inputs for the recalibrator switch setting calculator.
EDIT: Right-click on the links and select "Open in a new window". For some reason, the browser thinks it is a popup. :cuss:
Recalibrator & Speedcal Calculator
If you don't know the VSS rate of your stock or current setup, you can figure it out with the VSS calculator I wrote. That calculator uses as inputs the speeedometer gears, the differential gear ratio and the tire revs per mile as imputs. I put the stock values for my 96 Cobra in as default, so you can use that output for the stock VSS value for all Mustangs. Use "Ctrl-C" to copy and "Ctrl-V" to paste values between the calculators.
Ford VSS Calculator
If you don't know your tire revs per mile, you can use the Tire Size Calculator - 1010tires.com to figure it out.
Let me know if anything doesn't work or doesn't make sense.
I did a lot of research on the internet, and have created a couple of calculators that you can use to figure this stuff out.
Since the device recalibrates the VSS signal, you really need to know what the VSS signal rates are in order to calculate the switch settings. As a result, I used VSS rates as the inputs for the recalibrator switch setting calculator.
EDIT: Right-click on the links and select "Open in a new window". For some reason, the browser thinks it is a popup. :cuss:
Recalibrator & Speedcal Calculator
If you don't know the VSS rate of your stock or current setup, you can figure it out with the VSS calculator I wrote. That calculator uses as inputs the speeedometer gears, the differential gear ratio and the tire revs per mile as imputs. I put the stock values for my 96 Cobra in as default, so you can use that output for the stock VSS value for all Mustangs. Use "Ctrl-C" to copy and "Ctrl-V" to paste values between the calculators.
Ford VSS Calculator
If you don't know your tire revs per mile, you can use the Tire Size Calculator - 1010tires.com to figure it out.
Let me know if anything doesn't work or doesn't make sense.
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