Hello together. Has someone had experiences with a stage 1 chip tuning, preferably M850i. Can the engine idr be used if you have up to 100ps and 100NM more under the hood? How about the gearbox and a possible engine overload? There are many (probably serious) tuners far and wide. However, for example, Ac Schnitzer is far too expensive for me, as there are others who demand less even for more performance. I would be happy about experiences and reports and/or information!