clyons

I just went stage 2 and I believe this sound is coming up, in first I am just spinning but when hooking in second it sounded like the tires were hooking then slipping then hooking. On further listening it almost sounds like center carrier is loose or something slapping the car underside. If this is the similar sound as everyone else? anyone have a video or sound file of this? it would appear that I'll have to have a look as to what may cause this in the coming weeks.