Elma freefall acceleration is 10m/s2 but it runs in slow motion.
Time coefficient in Elma is 0.4368 while default time coefficient in motogame is 0.5 thus motogame is a little faster by default.
For you reference, wheel radius is 0.4m.
EDIT: if you want to measure freefall acceleration in real seconds than it is 0.190794m/s2 in elma and 0.25m/s2 in motogame.