Originally Posted by Justohigh
I've never ran a jb3 so I wouldn't know, but you do get updated maps so I would assume there should difference in drive ability and power. I just sold mine, but you should be able to find one for around $50
When I got my 335i, it was boring from the start. I added JB4 and DCI and it is still in the boring catagory. This car would really need several hundred more horsepower to seem "fast". My car will never get there as its a 335i.