MHD tuner Beta – Thoughts, logs and knowledge (Updated 04/07/18)


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.

Overall rating

Random Thoughts (constantly updated):


  • Another app update, will test the updated burble changes this weekend I hope.


  • Just another burble setting video, this time with the “soft aggressiveness” as seen in the picture below


  • Lots of updates since my last… update
  • Cold start delete works great, car is super quiet starting up at all times (neighbors definitely happy about this)
  • Top speed limit removed
  • Burbles!!!
    • Settings for this video are: 
    • This is the HIGH aggressiveness, damn it’s loud, shakes the car…


  • A couple things seem to happen consistently after a fresh map flash:
    1. SOS call malfunction error – This will be gone the next time you restart the car
    2. Rough idle – This has been reported frequently, and I can say from my experience it get’s better overtime. After some adaption runs (WOT) and daily driving my idle go’s back to normal in about 3-4 days on average
  • Torque limit is still there in 3rd and 6th gear


  • Latest maps are really awesome, went on a nice logging run today and had 0… ZERO timing corrections
  • AFR, boost, boost target, fueling are all rock solid
    • Fun side note, in the MHD beta chat I learned MHD keeps all the factory engine failsafes in place so it’s really hard to hurt something on your car from say AFR going out of whack or something)
  • The burbles (though I’m not sure MHD has modified them on these beta maps yet) are pretty awesome, that could be my downpipe swap but yea, it sounds awesome!
  • Decided to pull out the Dragy and do a little 1/4 mile run. I had a bad start (4.8s 0-60), I short shifted, I’m on my crappy runflats and it was cold out and I still got a 12.89s 1/4 mile


  • Just a random note here about the car adapting after a map flash. I’ve noticed that after the initial flash the car runs a bit rough. For a whole week I was unable to do any WOT pulls and it’s just not as smooth as it was prior to the map flash. It’s not bad at all but definitely not as smooth as after doing a few WOT pulls. I asked MHD about this in the BETA chat and they stated that a few WOT pulls are absolutely necessary to “smooth things out”
    • I tested this and yes, a few (4-5) WOT pulls absolutely smooths out low rev/city driving
    • More to follow when the new maps get released hopefully soon.


  • The latest maps (both stage 1 and 2) feel awesome, power delivery is amazing and it needs to be said again, shifts are soo smooth compared to the JB4.
  • There is a weird torque limit issue in 3rd and 6th gear on stage 2, MHD is aware and working on it.
  • California 91 octane sucks, I did a little experiment using straight 91 octane and 91 octane with 2.3 gallons of e85, logs below, as you can see, the timing was night and day
Straight 91 octane timing corrections


91 Octane with 2.8 gallons of e85 mixed in


  • 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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