I am about to send my computer off to Carolina Auto Masters for a little tune. My Question is what is it going to hurt if I get them to tune it for 3:73's w/o having them installed. I'll be putting them in within a month, actually more like a week or two. Should I wait or will it make a difference. BTW I only drive the car about 50-75 miles a week.

 

it'll only hurt your mph gauge in the fact that it won't work as it should (I think the speed reads higher than usual on the gauge; if you're going about 75 it reads 80 on the speedo.) It shouldn't hurt anything else.

 

Your shift points will be off and your line pressures will be off. Also it could affect your ABS brakes or traction control. The primary thing will be the shift speeds and TCC lock up points.

 

whoops, forgot about the automatics! doh!

us M6 guys don't have much to think about I guess...