[DATM3]

I have had a flash tune, Dinan Stage 1 & 2, Jb4 stage 1, jb4 +BCM stage 2, and flash jb4 stack between my M5 and M6. Be careful with a flash tune unless you know the people who are doing it and will do it properly as it requires removal of the ecu's and opening them up. Make sure they know how to open them up and reseal them properly. Some flash tuners drill holes in your ecu's then just plug them up or cover it up with tape, which I caution you do not want to do as it is a permanent hole in your ecu casing. I was really bothered by this when I got my flash tune as the tuner did not reseal the casing properly. I would ask them how they are doing it before you go with any flash tuner. Also, a lot of the tuners just buy files and flash them on your car instead of modifying themselves. I don't believe there are many tuners that actually adjust the parameters themselves on this platform. My only positive about a flash tune is that it has the ability to remove the top speed limiter and smoother power delivery. Also, sometimes issues occur several miles after a flash tune and diagnosing the issue is a PITA. Some tuners will deny that it is their tune that is causing the issues even after you prove to them the issue does not come back after you flash back to stock (especially the tuners that buy premade tune files).

Having said that, I currently run only the Jb4 +BCM on my M6. I like to have the flexibility to control the settings myself and can install and remove it anytime I want. It gives you the ability to turn off active sound, change maps, increase led brightness, remove CEL(if you have catless dp), log parameters while driving, all can be done on the fly. Terry is also very responsive to any questions you have via email.