You will have lots of different replies for this question
Mine, not necessarily the best or most efficient but at least for me most consistent or easy way of a good launch with the 1M is:
Totally dry, good tarmac, PSS tires (or any street tire which is grippier than the stock PS2):
MDM on, keep the rpms around 2000-2500 and go, change first to second around 6000, second to third around 6500.
Not something I thought about too much, just found myself easy and having fun with more or less the way I described above.
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"The mark of a great car is one whose overall competence exceeds what you should expect from its individual components and the 1M does just that", Chris Harris.
BMW 1M-SOLD-: TECH: Evolve Race+N55mids, Evolve IC, Michelin PSS, ER cp, aFe filter, CDVx, Vorshlag camber plates, BMS OCC EXTERIOR: trunk spoiler, blacklines, black grills, IND goodies INTERIOR: Alcantara steering wheel, steel pedals, custom mats, MPower e-brake.