BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Track / Autocross / Dragstrip / Driving Techniques
 
INDustry distribution
Post Reply
 
Thread Tools Search this Thread
      10-05-2008, 09:05 PM   #1
RQ
New Member
0
Rep
9
Posts

 
Drives: 08 M3 Cpe DCT, others
Join Date: Oct 2008
Location: S. Florida

iTrader: (0)

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.
Appreciate 0
      10-05-2008, 09:12 PM   #2
Dascamel
Lieutenant Colonel
Dascamel's Avatar
20
Rep
1,662
Posts

 
Drives: 2008 e92 M3, 2010 e91 328i
Join Date: Jul 2007
Location: Bakersfield, CA

iTrader: (0)

search....
__________________
2008 E92 M3 Jerez Black,DCT,Fox Red ext,Prem,Tech,19", ipod/usb, CF roof and trim
2010 E91 328i Space Gray,Black int, M sport, most options
2007 Montego Blue 335i (retired)
Appreciate 0
      10-05-2008, 09:13 PM   #3
MysticBlue
Major
18
Rep
1,315
Posts

 
Drives: '09 M3 DCT Coupe, ---'15 x50i
Join Date: Apr 2008
Location: Eastern Oregon... They call 'em rigs here

iTrader: (0)

http://www.m3post.com/forums/showthread.php?t=171460

http://www.m3post.com/forums/showthread.php?t=174854
Appreciate 0
      10-05-2008, 09:26 PM   #4
RQ
New Member
0
Rep
9
Posts

 
Drives: 08 M3 Cpe DCT, others
Join Date: Oct 2008
Location: S. Florida

iTrader: (0)

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!
Appreciate 0
      10-05-2008, 09:31 PM   #5
Ronin13
First Lieutenant
Ronin13's Avatar
United_States
8
Rep
362
Posts

 
Drives: DKG E92 M3, S2K, JGC
Join Date: Jan 2008
Location: STL, MO

iTrader: (0)

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
Appreciate 0
      10-05-2008, 09:43 PM   #6
rzm3
Moderator
rzm3's Avatar
224
Rep
4,603
Posts

 
Drives: E92 M3
Join Date: Aug 2007
Location: USA

iTrader: (14)

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).
__________________
E92 M3 DCT - AiM EVO4 Data Logger / AiM SmartyCam HD / KW Competition 2-Way / OMP ARS Racing Seats / Brembo GT 365 / Pagid Yellow RS-29 / Rear Seats Delete
Appreciate 0
      10-05-2008, 10:19 PM   #7
enfield
Civilian
enfield's Avatar
Canada
23
Rep
946
Posts

 
Drives: Jaguar F-Type V8 S
Join Date: May 2007
Location: Ontario

iTrader: (0)

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.
Appreciate 0
      10-05-2008, 10:41 PM   #8
RQ
New Member
0
Rep
9
Posts

 
Drives: 08 M3 Cpe DCT, others
Join Date: Oct 2008
Location: S. Florida

iTrader: (0)

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.
Appreciate 0
      10-05-2008, 10:43 PM   #9
RQ
New Member
0
Rep
9
Posts

 
Drives: 08 M3 Cpe DCT, others
Join Date: Oct 2008
Location: S. Florida

iTrader: (0)

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?
Appreciate 0
      10-06-2008, 06:30 AM   #10
enfield
Civilian
enfield's Avatar
Canada
23
Rep
946
Posts

 
Drives: Jaguar F-Type V8 S
Join Date: May 2007
Location: Ontario

iTrader: (0)

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.
Appreciate 0
      10-08-2008, 09:32 PM   #11
RQ
New Member
0
Rep
9
Posts

 
Drives: 08 M3 Cpe DCT, others
Join Date: Oct 2008
Location: S. Florida

iTrader: (0)

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.
Appreciate 0
      10-13-2008, 01:38 PM   #12
Dascamel
Lieutenant Colonel
Dascamel's Avatar
20
Rep
1,662
Posts

 
Drives: 2008 e92 M3, 2010 e91 328i
Join Date: Jul 2007
Location: Bakersfield, CA

iTrader: (0)

Good points though about being smooth and balanced before turn in.
__________________
2008 E92 M3 Jerez Black,DCT,Fox Red ext,Prem,Tech,19", ipod/usb, CF roof and trim
2010 E91 328i Space Gray,Black int, M sport, most options
2007 Montego Blue 335i (retired)
Appreciate 0
      10-13-2008, 01:49 PM   #13
footie
Major General
footie's Avatar
No_Country
160
Rep
7,507
Posts

 
Drives: ????????????
Join Date: Oct 2007
Location: BMW M3 will get a V6TT

iTrader: (0)

Garage List
2008 E92 M3  [0.00]
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.
Appreciate 0
      10-13-2008, 07:09 PM   #14
man02195
Lieutenant
man02195's Avatar
9
Rep
487
Posts

 
Drives: e90 M3 M-DCT, SG-status 111
Join Date: Jan 2007
Location: NC

iTrader: (0)

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.
__________________
E90 M3 Sedan | M-DCT | SG | Black Leather | Carbon Leather Trim | Premium | Technology | Enhanced Sound | 19's | Moonroof | Fold Down | Heated | iPod | Parkdist | Sunshade |Week 22 | Just unloaded from Emden | Performance Center Delivery July 17th (Great Experience!)
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 12:46 AM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST