UE4 Version 4.7.6 Physic behaves different PIE vs. StandAlone

In case somebody encounter the same issue, according to the reply at answer hub:

https://answers.unrealengine.com/questions/216065/why-is-physic-behave-different-in-pie-and-standalo.html

ue4 physic isn’t using a fixed time step, which causes physics behave different under different frame rate. The answer suggest tweaking physic substep in the project settings.