OK, I'll try and make it as clear as I can
Rollout is the distance the car travels per revolution of the motor.
In order to calculate rollout you need to know the following
Spur gear size
Pinion gear size
Internal ratio for your car. In your example it is 2.2:1
Value of pi=3.14159
Firstly work out the Final drive ratio for your car which is done by the following equation
Final Drive = (spur gear size/ pinion gear size) X Internal Ratio
To get the rollout figure use the following equation.
Rollout=(Tyre Diameter X Pi ) / Final Drive ratio.
(In equations above the symbol "/" means "divided By")
As an example for you, if your 414MII had a 128tooth Spur gear and 45Tooth Pinion (0.4 Module Tamiya ) with 64mm diameter tyres then your rollout would be calculated as follows.
Final Drive Ratio = (128/45) X 2.2
Therefore FDR equals 6.257
Rollout = (64 X 3.14159) / 6.257
Therefore rollout would be 32.13mm
Hope this is not too confusing