I'm curious about this as well. My car-see sig- has hit an indicated 150mph and I simply ran out of straight road but it was still pulling. I thought the current jb4 for the n55 couldn't defeat the electronic speed limiter? Even with the sport pkg it shouldn't get to 150+ should it?
--2011 335i xDrive coupe-6MT
--Premium/Sport/Cold Weather/Nav/Comfort Access/Harmon Kardon
--JB4 Stage 2 : BMS intake : Active Autowerke exhaust : ER charge pipe : cdv delete : M Sport shift knob : 12% tint : clear bra