Enter The New Gear Size First, then the old gear size and then RPM with OLD gears.

OK, so you know now this is best when using the RPM reading in the 1:1 gear (ex: 3rd gear with the 4R70W) with the old differential gear setup. This calculator DOES NOT account for Torque Converter Slip.

1. Enter Your New Gear Ratio :
2. Enter Your Old Gear Ratio :
3. Enter The Old Gear RPM You Tested at in 1:1 :
4.

Answer to The New Gear RPM Value in 1:1 Ratio will be below:


What about when in O/D?

Type your answer from above here to figure RPM in 4th (O/D):

4th Gear RPM after Gear Swap: