Need help with nasty sound

[freshguacamole]

Hey guys first time posting on this forum. I have a 1991 240sx with a sr20det. Here's the problem; when I launch the car or even when the wheels just spin when its wet there is a repeated banging in the back end that continues until i let off the gas. It sounds like metal is just slapping together. Anyone have any ideas? I appreciate the help. Let me know if I haven't been clear enough. Thanks!

[Rogue One]

Could you post a sound clip to youtube so we can get a better idea of what your referring to?