OK, new improved time. Best pair average:
6.20s. Not thrilling, but starts to be in the right ball park with other benchmarks:
Jaw_F430 : 6.05 (05gb,15%,Bigger I/C +other mods) BigShow : 6.075 (03gb, Lohen 225, manifold) Edenalig : 6.15 (02gb, 15%, MTH, Alta CAI, Manifold, Miltek)
Improvement might be due to colder temperature (-2.5C) or lighter car (1/3 tank vs full tank)...or then BMW accidentally fixed some problems while playing around with my car (and officially not finding any faults).
Note. Both tests are with heavy 205/45/17 winter runflat tyres and OZ Superturismos. I presume that with my 215/40/17 F1s and Ultraleggeras the time might still improve a notch.