My car (318is) has a custom intake and thats about it. I have an aftermarket rear box but it doesn't help power I believe. The 325i has a chip only. Both are 5spd.
We lined up (desert stoplight, noooooobody around), I got a decent launch (3500 or so), 1st gear he pulled.....2nd he pulled....slightly into 3rd he pulled. We shutdown at about 100 because the speed limit was 45(mph).
I was impressed. The M20 pulled smoothly in every gear and the M42 just fell flat on its face. Probably a good 3 car lengths to 60 in the 325i's favor.
Good times were had by all