Thanks for posting the charts guys - pretty good figs for both cars
Looks like v little difference in peak torque figs, but sixspeeds looks a bit flatter overall.
Maybe we should do a group Z4M trip to a Rolling Road - Surrey or Austec in Gatwick? - and with a mix of cars, from completely stock, to ones with just one non-stock item each, ie filter, exhaust, then could get a reasonable idea of what difference the mods make?