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      10-05-2008, 09:05 PM   #1
RQ
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Maybe wrong section: tracking a DCT E92?

Apologies in advance if I am posting this in the wrong section.

First post here - for reference this is my 3rd M3 and I recently got rid of my M6. Among other cars. But that is besides the point, here is my problem:

I recently bought an 08 DCT coupe, strictly as a daily driver, but still!

I happened to be at a track weekend and my race car broke an axle so I figured I'd take the M3 out for a bit...

Loved the power, nice enough suspension and good brakes given stock BUT WTF is up with the tranny??

At threshold breaking the downshift paddle becomes disabled, period. Unless I lifted a bit. I tried all modes possible, fact was that regardless of setting under threshold conditions the *** would just be dead. I did this for several laps, very repeatable.

Trying to exit a 2nd gear turn on 5th gear is not fun to say the least.

Hopefully I am just missing a silly setting that makes it all good. Any thoughts appreciated.
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      10-05-2008, 09:12 PM   #2
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search....
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      10-05-2008, 09:13 PM   #3
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http://www.m3post.com/forums/showthread.php?t=171460

http://www.m3post.com/forums/showthread.php?t=174854
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      10-05-2008, 09:26 PM   #4
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Thanks folks, I did try the search option and good threads but again, very specifically, the problem is:

If I threshold break my DCT M3 from, say 130mph to 40mph my left paddle is completely unresponsive.

IF I were to lift slightly it becomes responsive again but that unsettles the car.

Any on topic feedback welcome!
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      10-05-2008, 09:31 PM   #5
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Yes. It is an issue. Members and mags have experienced it. The software update threads posted earlier are discussions of waiting for a fix for it among a few other issues. Try this google search to find the track threads...

dct downshift site:m3post.com
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      10-05-2008, 09:43 PM   #6
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Here is a more useful thread.
http://www.m3post.com/forums/showthr...&highlight=dct

Use "Advanced Search" for "DCT" "Search in Titles Only" and you will find lots more.

From talking to Mike from this forum, he said the best way to deal with this problem is to shift after you finish braking before entering the turn.

And don't feel too bad about it, even the CLK AMG Black has the same problem (yes I know it's an auto).
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      10-05-2008, 10:19 PM   #7
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I experienced this too. The issue according to my understanding is that when traction control / ABS is about to (does not HAVE to) kick in it tends to disable the downshifts. It was very annoying at the track but I learned to adjust.
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      10-05-2008, 10:41 PM   #8
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Thanks folks.

Again this M3 is a daily driver but it was just dissapointing that the tranny "froze up" consistently in a track environment, which frankly makes it useless for any kind of track application in its current state.

These are not traits that will ever manifest in a street environment so no issues.

And BTW I still cant think of a better cruiser than this M3, it does everything great and to be clear this is not a put down on DCT.
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      10-05-2008, 10:43 PM   #9
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Quote:
Originally Posted by enfield View Post
I experienced this too. The issue according to my understanding is that when traction control / ABS is about to (does not HAVE to) kick in it tends to disable the downshifts. It was very annoying at the track but I learned to adjust.

I posted before you did... how do you "adjust" without upsetting the car?
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      10-06-2008, 06:30 AM   #10
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Bottom line - you have to brake hard at the beginning of the braking zone and then ease off - as you are are easing off the brakes you have to downshift. You turn in at the turning point after all this is done and the car is balanced.

What I had been doing was the street braking thing - start of gradually and progressively press harder and release at the turning point. This caused the shifting issues.

If you brake hard at the beginning of the braking zone and then ease off and downshift as you are easing off then all will be well and the tranny will be just fine thank you!! As you probably know gear changes occur towards the half way point in the braking zone if you are going down one gear. If you need to go down 2 gears then one change occurs when there is 2/3 of the braking zone left and the second change occurs when there is about 1/3 of the braking zone left. This is also the point when you should be almost off the brakes to balance the car prior to the turning point otherwise you can understeer like most automative journalists

Hope that helps.

Last edited by enfield; 10-06-2008 at 07:39 AM.
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      10-08-2008, 09:32 PM   #11
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Thanks. Not a reasonable compromise or adjustment though. Precludes normal threshold or trail braking.

Again not a problem for me. Big problem for enthusiasts that buy this car with a track expectation, unless this will be part of the software update that solves the stalling too.

Onwards.
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      10-13-2008, 01:38 PM   #12
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Good points though about being smooth and balanced before turn in.
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      10-13-2008, 01:49 PM   #13
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I'm hoping the software upgrade will have cured the downshift problem but if not I always thought that braking hard at the start and easing slightly near the end of the braking zone should allow you to downshift without any problems.

P.S.
I see you are all talking about having the car balanced on entry. I take it you all know you should be on the throttle no matter how little when entering a corner. Reason being is that without throttle you have zero balance and zero load on the suspension.
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      10-13-2008, 07:09 PM   #14
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Quote:
Originally Posted by enfield View Post
Bottom line - you have to brake hard at the beginning of the braking zone and then ease off - as you are are easing off the brakes you have to downshift. You turn in at the turning point after all this is done and the car is balanced.

What I had been doing was the street braking thing - start of gradually and progressively press harder and release at the turning point. This caused the shifting issues.

If you brake hard at the beginning of the braking zone and then ease off and downshift as you are easing off then all will be well and the tranny will be just fine thank you!! As you probably know gear changes occur towards the half way point in the braking zone if you are going down one gear. If you need to go down 2 gears then one change occurs when there is 2/3 of the braking zone left and the second change occurs when there is about 1/3 of the braking zone left. This is also the point when you should be almost off the brakes to balance the car prior to the turning point otherwise you can understeer like most automative journalists

Hope that helps.
I did it a little differently, and found the car stayed more balanced and I was quicker. Do your braking just as you always would, stay on it hard, all the way to the turn in point (or after turn-in if you have to trail brake a little.) As soon as you lift off the brake, do a quick downshift-downshift, as you start to apply the go pedal. I found the shifts could happen in the 50 feet or so as I crossed the track towards the apex.
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