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      07-11-2016, 02:41 PM   #1
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DCT acting up related to supercharger?

Not sure if anyone can help me, but worth a shot. My DCT has been acting pretty strange lately, and I'm not sure what to make of it. I've flashed both the GTS software, and then the regular Euro software (which I am currently running). My issues seem to have began when I flashed the GTS software, but I am showing different symptoms now that I am supercharged.

Long story short, I noticed a week or so after I did the GTS software that the car would occasionally have a delay shifting gears under normal throttle. i.e. you pull the shift lever up (or use the shifter) and a second or so later (a noticeable delay) the car would then shift.

Now, after my supercharger install, I am noticing the car occasionally seems to have a hard time finding the next gear. What I mean is, say I shift from 3rd to 4th (where it seems to happen most), the car will indicate 4th gear on the dash, but will hold the RPM's and not drop down as it should when you change gears. A second or two later, the car's RPMs will lower, and I can accelerate in 4th. I have not been able to tell yet if the car is actually holding 3rd gear, or it is just boost pressure built up that hasn't escaped, and is making the car want to continue forward during the gear change (hope that makes sense). I had a slight theory that maybe my bypass valve is too tight and needs adjustment?

Last little issue is that when I drop a couple gears (such as using the DCT kickdown feature), the car will hesitate to go at first for a second or two. Then, all of a sudden, it will grab, and the car will lunch forward like you would expect. So it goes like this..cruising in 5th gear, push pedal to floor, click left shift lever to go to lowest possible gear, car will change gears (can feel it change gears), RPM's will raise as normal, car will then hesitate (i.e. not go anywhere, feels as though the car isn't getting fuel) then the car will eventually take off and accelerate (rather quickly).

Are these all normal characteristics of the DCT for a supercharged M3? Possible my bypass valve is too tight and isn't letting boost pressure escape the way it should, causing issues when I change gears? I don't feel as though the clutch is slipping, it literally just feels like the car either wants to keep accelerating when you change gears at times (or is hesitating to change gears, can't tell which one it is) and the car will hesitate or pause when a huge drop in gears to higher RPM's takes place (happens with both the DCT kickdown and when flooring it in D mode and the car downshifts for you, for example, from 4th to 2nd.

Anyone have any input? I am worried either my clutch is slipping (though it doesn't seem like it is to me) or (worse) there is something wrong with my tranny. Of course I tend to worry, so I hope I am overreacting and this is all normal behavior or something simple like an improperly adjusted bypass valve or a software issue.
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      07-11-2016, 07:33 PM   #2
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Which supercharger/software is it? I have the ESS-VT1-550 kit w/ECU+DCT tune and had shifting issues when I first loaded the ESS DCT tune. I had to clear the ECU learning using the ESS software. Once I did, the sloppy shifts went away.
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      07-12-2016, 12:15 AM   #3
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ESS 550 and ESS tune. I didn't get the DCT tune from them though my tune had two files and one said something about DCT.
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      07-22-2016, 06:04 AM   #4
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anyone?
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      07-22-2016, 11:11 AM   #5
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I know at least one other member here had a supercharger specific DCT tune put on his car (or it was at least edited somewhat to better accommodate the supercharger). Trying to remember who that was.
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      07-28-2016, 08:18 PM   #6
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ESS comes in two you load No.1 and then Number 2 in that order. It said DCT because the file was made for a DCT car. I recommend you flash the DCT back to Stock and give it a go.
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