[rzm3]

i recently installed H&R street performance C/O on my 335xi coupe. everything works fine except -

when accelerating full throttle at higher gears (4, 5, 6) and low RPM ~1500-2000, car vibrates (vigorously) for around 0.5 seconds initially. and after the vibration, everything goes back to normal. and no, this is not because i am driving over a bump...

i am a mechanical engineer, so technically speaking, it feels like the new suspension changed the natural frequency of the car, and when the engine is at a certain speed and transmission in a certain gear, the car resonates with the frequency of the engine. thus the entire car vibrates.

any suggestions on what i can change?