MHD tuner Beta – Thoughts, logs and knowledge


So I was accepted into the MHD F-series N55 beta. My vehicle has a somewhat rare “172S ECU” so I (and some others in the beta group) are about a week behind the other ECU versions. All communication is done through a Whatsapp chat. The members in the group, MHD and the ECU tuner people have been really cool and very helpful.

Logged pulls done in 4th gear, WOT around 2500RPM to redline + a couple seconds in 5th gear.

The plan is to update this blog post throughout the beta process so check back often.

Random Thoughts (constantly updated):


  • First ECU flash from MHD. MAP1, 91 octane. Installed in less than 3 minutes
    • Note, no e85 in the tank for this initial testing per MHD’s request
  • Compared to the JB4 with e85 the MHD flash definitely feels less powerful BUT the shifting is SOO smooth compared to the JB4, it’s a night and day difference.
  • I experienced some weird low RPM surging in Sport-Sport+ mode at low RPM’s that seemed to go away further on the test drive. Will retest this soon to see if it’s a car cold thing or an adaptation thing.

1/10/18 Logs:

  • Stage 1, 91 octane map (revision 1)
  • I’m a complete novice to reading logs but here’s my very unqualified analysis.
    • Boost and boost target are looking great, very closely following each other.
    • Timing looks good, there was one drop of about 3-4 degrees in the pull, pretty sure that’s just fine. It’s sloping upward and any concern from how I understand it would be multiple 3-4 degree drops in timing on a pull could be an indication of knocking
    • AFR got pretty low towards the end of the pull, logs show 12.09 @ 6100 RPM but this is also when I shifted to 5th (short shift loser here), not sure if that’s normal or what.
    • No issues with IAT
    • STFT aka TRIMS I have no idea…
    • WGDC looks ok, it’s not high so no boost leaks or pushing the turbo to the max


  • Initial unlock of my ECU. I purchased my DCAN cable from Twisted Tuning, arrived in CA from NY in like 2 days
  • Hooked the car up to my NOCO car charger, put my phone on airplane mode and unlocked my ECU through the MHD app. It took about 30 very nervous minutes
  • MHD app reported it was installed, tested the logging function and that all worked fine.
  • No issues what so ever with the initial unlock.



Stay tuned for more updates!


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