BMW E34 513i Drift car Rotary s/c 13b swap m90 eaton crazy sound HD

BMW E34 530i v8 with a 13B-rew swap with stock port. Initial tuning and sorting out the blank MS3X map. 2.5" exhaust with Magnaflow oval rear muffler. Gen 5 Eaton M90 with silencer hole blocked and no bypass. Not more than 30/40% throttle and already building 1.6bar of boost from idle. Lowered on CEIKA Coilovers. . The diff ratio appeared to be way too low being a 3.05 on the stock 530i v8 diff and FD gearbox. Swapping it for a 4.45 for the next session!