My guess here would be that while the 370z "might" handle better, the overall performance of the 135i beats it around the track. Your almost always in peak tq with the 1er and its handling is very predictable.
Would like to see this same driver test the 135i against itself with the addition of a tune! There are a million 1/4 mile before and after but I am curious to see how much quicker it is around a track.
RB EVO - Best ET: 10.9 | Best MPH 133.4