Live Tuning Options
Live Tuning means you can change tables and values of the ECU calibration ('tune') with the engine running. Ideally without any lag and instant feedback from the engine operation.
This helps with dyno tuning and eliminate the need for restarting the car and flash between each runs. Basically there are two ways of changing values on-the-fly:
A) Modern ECUs have enough RAM available to have whole tables or even the complete calibration data stored there and modifyable.
BMW also moved several values and even small maps to the RAM while the cars where in developement, but never the whole calibration, because MS42 and MS43 are short of free RAM space.
Or B) by emulating the whole flash memory. Thankfully by today there are fast enough micro controllers to handle this.
Currently there are two options on the market that work for MS43 out of the box: