Installed the JBD today. Hard to judge the speed by seat of the pants, since the engine just seems to loaf, and speed builds up without the sound of a high winding gas engine. But now the car is definitely quicker than my gas 335i ever was stock. I think the best I got on the 335i was 13.3-13.4 sec in the 1/4 mile.
JBD 335d results. (otherwise stock, RFTs, had some stuff in the trunk)
72F Ambient Temps. JBD setting 2 notches above the middle position.
13.2 at 105.1 mph 0-60 in 4.7 seconds
pretty impressive for a simple 10 minute install. This car is an absolute joy to drive around town. So effortless to jet away from traffic without winding out the engine.