so… are you circuiting the car ? drift or drag ? because like peter said, if you want the slowest time weld your diff, from my experiance i think a welded diff takes a little time to adjust your drifting to, as it does give a little understeer, its almost as if the car wants to start the corner a little later than you would, but anyways if your dragging welded is perfect, depending on the power you have, but peter has around 300 and hasnt had any problems for 2 years ? and hes not gental lol