[dereksM3]

Not trying to strike a debate between tunes or piggy backs but I have a Dinan Sport which essentially is the exact same as a JB+ and I have zero shift weirdness. The only two items to note were to first 30-40 miles had some odd surging at low RPM's until it adapted and you get a touch slower shifts at redline with the torque limiting coming into factor at times (manual mode is virtually identical shift speeds). I run 92 octane and on the Sport +3psi setting and it's a very noticeable difference and runs very smooth.

However, my only complaint I can say is stock form the B58 feels so linear it almost feels like it lacks a turbo and with the Piggyback you feel the boost come on aggressively at the low end creating that torque surge reminiscence of a turbo engine. From a drivability standpoint this is where a JB4 tuning the boost curve to create a linear powerband would be beneficial. Other than that every single piggyback thus far has some issue in regards to the B58. Dinan, JB+, JB4, AA, etc. all have drivability complaints, torque intervention, etc. JB4 probably has the best chance to cure this with access to the CANBUS but until then it's almost impossible to say especially considering BMS is on firmware 7 or 8 in a pretty short time? Check the N54Tech B58 forum to see the latest map guide as it's recently been changed with their latest firmware release...they seem to be dialing the aggressiveness back.

Personally I would buy just a JB+ or Dinan Sport and hold out until ECU access comes around or get MPPSK. None of the Piggybacks have 100% OEM drivability and that's just life for the time being.