I have the G56 Stage 1 kit on my car and a standard ECU. I was told by the G56 people that their Stage 1 kit was designed to run within the programme of the standard ECU and it seems to do this very well. It doesn't make your ears bleed like the KH one I heard did, if that is a consideration.
Is your M3W an early, mid or late Mk1 or Mk2? Mine is an early Mk.1 (April 2012) so still has the earliest version of the software in the ECU. I believe this over advances the ignition over 4000 RPM so that a change in pipes is only a partial cure. Reading the G56 blurb I think their ECU has to be programmed on a rolling road. Maybe the ideal cure would be G56 pipes and a KrazyHorse ECU.
