[bNks334]

OP, there isn't much to gain by looking into DSC's calibration imo. To answer your question though YES the x28i DSC is calibrated differently than an x35i. DSC measures more than wheel slip. DSC is comprised of a nest of functions (CBC, ASC, EBV etc) that work together as one active system. Pitch, yaw, wheel speed differential, steering angle, among other values are all considered dynamically in order to keep the vehicle from under-steering or over-steering. This is happening regardless of how much power you are putting down. If DSC is kicking in too much for your liking than either put enough rubber on the car to get the power down properly or turn DSC off. Keep in mind that even after turning DSC completely off (Hold traction control button for 5 seconds) you'll still have the e-diff intervening.

The differential between the coding of the two cars is so minuscule that I honestly doubt you'd even be able to tell the difference between the coding changes. You might get what an additional 1* of slip before DSC intervenes? You may also cause DSC to intervene inappropriately as the x35i is coded to control a heavier car with greater brake torque among other unknown values the car uses to determine how aggressively to intervene...