I think you might be interested in this since the F12 and F10 exhausts are relatively the same.
I recently dyno'd my M6 stock (02/04/13) and then got the Meisterschaft Super GT Racing exhaust (no valves, I like noise all the time) installed this past Friday. Here are the dyno chart overlays and again thanks to Tom and team at EAS for doing this. As most of you Orange County guys know they are the "go to" out here for all your needs BMW wise.
Now the conditions were different from Monday to Friday so I take these with some cautious review but the car did indeed feel better after the exhaust was installed. Friday was cooler by about 7 degrees and since it was different days things could occur but the operator and the dyno are the same and the strap down procedure was the same as well. Im glad I didnt lose any power and the Meisterschaft is similar in sound levels (noise volume) to the Eisenmann Race axle back I have on my F10 M5. The sounds are different though. The Meister has a deeper throatier sound while the ERace is more exotic and a slightly higher pitched tone. Both are great for different reasons. I like Meister for its appearance, the cans are polished and the under piping is all stainless up to the resonator. I like the Eisenmann for the actual tips; no center supporting stick in the middle of the exhaust tips; Im not sure why its there but I will be cutting that out this week. The Eisenmann seems to provide more sound at coast down speeds to stop too. Some may not like this but I do. Ill be happy to answer more questions if you have any:
These are standard correction graphs and the exhaust appears to have produced some power and tq:
