|
|
09-22-2008, 01:50 AM | #45 |
Captain
30
Rep 955
Posts |
I found this on the M5 Board back when I had one. Applies to SMG or M-DCT
"Without being on the accelerator the downshift throttle blip will assume you are still decelerating and rightly be short of the perfect rev match. It blips up enough to protect the transmission and clutch and to prevent an engine-load jolt, but not so much that it slows the engine load. When you do your final gear downshift in anticipation of entering and accelerating through/out of the corner, you should be giving some gas when braking and downshifting (heel-toe or left-right foot brake-gas). This signals the SMG to rev match higher and when it completes the shift, it will start loading the suspension through the turn-in for better balance and a smoother/faster braking/acceleration transition." |
Appreciate
0
|
09-22-2008, 02:41 AM | #46 | |
Banned
78
Rep 2,244
Posts |
Quote:
Maybe BMW will release some official news regarding the update soon. |
|
Appreciate
0
|
09-22-2008, 07:06 AM | #47 | |
Veni Vidi Vici
89
Rep 2,750
Posts
Drives: '11 JB/BBe-6sp-e90
Join Date: Jul 2008
Location: Macungie PA
iTrader: (0)
Garage List 2011 e90 M3-Sold [8.50]
2003 RS6 - Sold [0.00] 2009 e90 M3 - Gone [0.00] 2003 M3 SOLD [0.00] old 2002 [10.00] |
Quote:
__________________
Dinan compliment of stuff plus PF rotors and RG63s. Enough for now. Why, yes. I am an abrasive bastard. |
|
Appreciate
0
|
09-22-2008, 11:24 AM | #48 | |
Original Bavarian Heritage
22
Rep 354
Posts |
Quote:
The DCT downshift problem is a software related feature/fault and has nothing to do with you being off or on the throttle while downshifting. I wonder if there is really anybody out there that has driven their M-DCT car hard on the track that didn't experience this problem??? Sprited driving on the street doesn't count, as I don't think that anybody would be going 140MPH and brake down to 50MPH in the shortest distance possible...
__________________
-------------------------------------------------------------------------------------------------------------- 2008 E92 M3 M-DCT - Sparkling Graphite - Fox Red - Tech Package - Premium Package - Moonroof - Enhanced Premium Sound - HD Radio - iPod USB interface - PDC - Remus Race Exhaust |
|
Appreciate
0
|
09-22-2008, 12:38 PM | #49 | |
First Lieutenant
33
Rep 379
Posts |
Quote:
There should be a "OFF" button for the DCT safety features, like for the DSC. |
|
Appreciate
0
|
09-22-2008, 12:41 PM | #50 |
Original Bavarian Heritage
22
Rep 354
Posts |
that would work for me - in particular since the problem doesn't show up in daily driving...
__________________
-------------------------------------------------------------------------------------------------------------- 2008 E92 M3 M-DCT - Sparkling Graphite - Fox Red - Tech Package - Premium Package - Moonroof - Enhanced Premium Sound - HD Radio - iPod USB interface - PDC - Remus Race Exhaust |
Appreciate
0
|
09-22-2008, 01:01 PM | #51 | |
Dishonorable Discharged
100
Rep 181
Posts |
Downshift
Quote:
Last edited by MarksM; 09-22-2008 at 01:02 PM.. Reason: sp |
|
Appreciate
0
|
09-22-2008, 01:09 PM | #52 |
Major General
1072
Rep 8,008
Posts
Drives: i4M50
Join Date: Oct 2007
Location: No where fast
|
Does this fault surface the very first time you downshift under very heavy braking or does it take a couple of laps before it happens. If the answer is a couple of laps or so then I am under the impression that it's an ABS issue, if not then I am stumpe.
|
Appreciate
0
|
09-22-2008, 01:23 PM | #54 |
Brigadier General
124
Rep 4,145
Posts |
I can confirm that this is true for SMG II. It describes that system exactly. I am hoping this "feature" gets added back for DCT.
__________________
2017 F80 YMB.
|
Appreciate
0
|
09-22-2008, 01:26 PM | #55 |
Original Bavarian Heritage
22
Rep 354
Posts |
first lap in the first session - consistently
__________________
-------------------------------------------------------------------------------------------------------------- 2008 E92 M3 M-DCT - Sparkling Graphite - Fox Red - Tech Package - Premium Package - Moonroof - Enhanced Premium Sound - HD Radio - iPod USB interface - PDC - Remus Race Exhaust |
Appreciate
0
|
09-22-2008, 02:30 PM | #56 |
Private First Class
13
Rep 110
Posts |
the back in the trunk of my M3...do you all notice there this HUGE silver box sort of like a hardrive.. I am guessing thats the main computer system that runs the car including ECU.. Am I right?
please correct me if I am wrong.. |
Appreciate
0
|
09-22-2008, 02:31 PM | #57 | |
Brigadier General
125
Rep 3,071
Posts
Drives: E92M3-E46M3-E46Wagon-E89Z4-E36
Join Date: Dec 2006
Location: Greater St Louis Metro area
|
For me it was usually second lap of each session. My first laps are always slightly slower as I let the tires and my brain come up to temp.
I'm not an engineer but I disagree that this is ABS related issue, because I'm not into the ABS when the downshift ignore occurs. The tranny has accelerometers build into it and my suspicion is that when the tranny senses a certain deceleration value it doesn't downshift in order to prevent the rear wheels from breaking loose due to the combination of wheel braking and engine braking overcoming the rear wheel traction. Not that was ever an issue with SMG, it seems as if the DCT engineers erred to much on the side of safety. Quote:
__________________
Invest Wisely...The best mod for your money?? BMWCCA high performance driver's school. The mod that lasts a lifetime and improves the performance of any car you drive[/LEFT]
|
|
Appreciate
0
|
09-22-2008, 02:38 PM | #58 | |
Brigadier General
125
Rep 3,071
Posts
Drives: E92M3-E46M3-E46Wagon-E89Z4-E36
Join Date: Dec 2006
Location: Greater St Louis Metro area
|
Quote:
Are you planning to tie this into the DCT issue or is this a
__________________
Invest Wisely...The best mod for your money?? BMWCCA high performance driver's school. The mod that lasts a lifetime and improves the performance of any car you drive[/LEFT]
|
|
Appreciate
0
|
09-22-2008, 02:53 PM | #59 | |
Moderator
7506
Rep 19,370
Posts |
Quote:
|
|
Appreciate
0
|
09-22-2008, 02:55 PM | #60 |
Moderator
94
Rep 1,920
Posts |
Depends on which box. There is an amp in the drivers side "wheel well" and the BMW Asssit module box is under the center trunk mat area.
__________________
Tim <--- apparently likes "3" cars
2014 E63S -- The Rocket 2014 F30 328i -- Kids car 2008 E90 M3 -- Sold 2004 GT3 -- Sold 1997 M3/4 -- Sold 1995 M3 -- Sold |
Appreciate
0
|
09-22-2008, 02:59 PM | #61 | |
Moderator
94
Rep 1,920
Posts |
Quote:
Pulling the ABS fuse/relay MAY work....it may also cause the car to freak out too. Who knows what it would do to the DCT... Also, on my GT3, if you had a wheel "lifted" (going out of a step driveway at an angle), and tapped the brakes, it would cause an ABS fault and disable the system for you. There was no "shut off" for the ABS taht I was aware of, but this worked everytime. Maybe the M3 will also disable it if it senses a fault. Just had a thought...............maybe unplug one of the ABS sensors (pick a wheel!). I am sure it will cause a fault. Being as it is in fault mode, it may deactivate the system entirely. Worth a shot, and it would be easy to do and reverse.
__________________
Tim <--- apparently likes "3" cars
2014 E63S -- The Rocket 2014 F30 328i -- Kids car 2008 E90 M3 -- Sold 2004 GT3 -- Sold 1997 M3/4 -- Sold 1995 M3 -- Sold |
|
Appreciate
0
|
09-22-2008, 03:02 PM | #62 | |
Captain
30
Rep 955
Posts |
Quote:
If you want a full rev-matched downshift you must give it gas while downshifting. If you just brake while downshifting it only blips enough to protect the transmission & clutch. I know this well since my last 3 BMW's have been either SMG II, SMG III or M-DCT |
|
Appreciate
0
|
09-22-2008, 03:11 PM | #63 | |
Dishonorable Discharged
100
Rep 181
Posts |
Your suggestion
Quote:
Because nothing short of gentle braking worked. |
|
Appreciate
0
|
09-22-2008, 03:14 PM | #64 |
Private First Class
13
Rep 110
Posts |
|
Appreciate
0
|
09-22-2008, 03:18 PM | #65 | |
Brigadier General
125
Rep 3,071
Posts
Drives: E92M3-E46M3-E46Wagon-E89Z4-E36
Join Date: Dec 2006
Location: Greater St Louis Metro area
|
Quote:
I'm not discounting you have a lot of SMG/DCT experience, I just haven't felt what you're saying.
__________________
Invest Wisely...The best mod for your money?? BMWCCA high performance driver's school. The mod that lasts a lifetime and improves the performance of any car you drive[/LEFT]
|
|
Appreciate
0
|
09-22-2008, 03:22 PM | #66 | |
Dishonorable Discharged
100
Rep 181
Posts |
Your suggestion
Quote:
Because nothing short of gentle braking worked. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
Thread Tools | Search this Thread |
|
|