Grinding sound on launch?

[GavinMcKay]

Hey all, getting a grinding sound on launch with my 08 535xi. It is stage 2 MHD with catless downpipes and a VRSF intake so probably around 370 or so whp. I also have xhp stage 3 with none of the settings changed. It seems that this sound only occurs in 1st gear, and only when the car is under near or at wot, it doesn't occur until 90% throttle, so my guess is it has something to do with torque. On hard launches when I hold the brake, it also occurs before I let off the brake to launch. Keep in mind it is an xdrive car. Here is a link to a YouTube video showing the sound:

Any ideas would be appreciated

 

[chef423]

Transmission bushings?

Have you serviced the mechatronic sleeve at all?

Ah, wait, I just saw xDrive...my E90 just uses 2 wheels in the back to push the car. I assume xDrive is all-wheel?

 

[GavinMcKay]

Transmission bushings?

Have you serviced the mechatronic sleeve at all?

Yeah I did the mechatronics sleeves like a year ago when one of them cracked. I'll check out the bushings as well.