Is there a speed limit during the offline start procedure?

[Whazaa]

Hi! I have a motion rig and during the start procedure (double lines until green lights) the motion rig is very jerky and jumps back and forth. After the race starts the rig acts as normal. What is going on? I don't think I'm speeding (if there is a speed limit like 70km/h when racing online). Please help before I destroy my rig...