I have a 2004 330ci that has AA twin screw supercharged, headers and exhaust. I am trying to figure out the perfect combination for the differential. I am not trying to get limited wheel spin and still have some top speed. I cannot even find ou what is has in it now. Some say 2.73/ 03.07 or 3.38. can anyone help or been through this experience before? My biggest poblem is getting any torque in thir gear on.It is a monster form the start and running through the gears. But if ou just punch it from third it doesn't seem to have much torque. Any ideas? Wheel a differential help with this?