Loud knock under center console

[Dsm_Roly]

Okay I installed a transmission earlier this season, I wasn't able to really drive it until know because I had a horrible idle surge but I finally got that under control. But as I took it out for a spin I noticed that if I open her up, once it reached somewhere near 4k or 5k there's a violent shaking under my center console. Not sure what it could be let me know if anyone has any ideas?

 

[cheap90gsx]

I've had problems with my rear drive shaft thumping under hard boost and hard shifting.

 

[1stGenTSi]

I've had problems with my rear drive shaft thumping under hard boost and hard shifting.

This is most likely your problem. Get under the car and wiggle the driveshaft. If it has a lot of play you need to replace the carrier bearings. Or fill them with silicone. Thump Fix Carrier Bearing