Dyno tuning isn't needed nor is it possible with the JB4 for the F10. Not sure if the JB4 has valet mode or not but even if it is you can't change maps without your laptop at the moment for our cars. It maybe available once Terry gets the map switching function to work through our dash but that's later on.
Remember guys this isn't a full tune where it reprograms your existing software (think Dinan, Cobb, GIAC). What all JB tunes do is intercept various sensors throughout the motor as well as a minimal part of your ECU and alters its signal to basically trick your ecu to run more boost to achieve more power. Our motors adjusts boost based on conditions it is seeing. Bmw designed the car to make 300HP in the middle of winter, during a 100 degree summer day, in a city that has a elevation of 8K feet above sea level regardless so the ecu has the ability to raise/lower boost pressure based on various readings. This is why devices like the JB4 can easily up the boost in our cars to make more power since it changes what the ecu is seeing. Basically the ecu thinks it needs more boost to achieve 300hp when in fact you are really making much more with the JB. There is a huge debate on the N54 side about this method so i won't go there (search if you really want to learn more) but there are tons of guys running this on the 335 board without any issues so I personally would say it is safe enough for our cars. Is it the best solution? No but it is the ONLY solution for more power now aside from the $1300 Hartge tune which i suspect does the same thing and JB products have had a pretty good track record and excellent customer service.
Last edited by Alan l.; 08-06-2012 at 10:28 AM.