09-20-2014, 03:25 AM | #1 |
Private First Class
26
Rep 116
Posts |
Bucking while accelerating - DCT?
When I have M Engine Dynamics set to Sport Plus and Drivelogic set to S3, the car bucks under heavy acceleration. Anyone else?
Last edited by mkoesel; 09-20-2014 at 07:29 AM.. Reason: Readability/Clarity |
09-20-2014, 04:46 AM | #2 |
Lieutenant Colonel
216
Rep 1,793
Posts
Drives: 06' E90 330, 20' F97 X3m
Join Date: Feb 2006
Location: L.I, NY
|
Yes it's very sensitive/ jumpy. I've learned to feather it out if I'm not hammering on it from a dead stop.
__________________
LIVE FAST..DRIVE FASTER!! |
Appreciate
1
Revvvm3169.50 |
09-20-2014, 05:22 AM | #3 |
Banned
43
Rep 1,147
Posts |
It can be jerky but it's mostly user error.
|
Appreciate
1
Shatterproof41.50 |
09-20-2014, 05:51 AM | #4 |
Lieutenant Colonel
444
Rep 1,643
Posts |
My E90 did the same thing. Sometimes so badly, it made me look like a novice stick driver with a touchy clutch.
__________________
2013 Jerez Black/Black E92 ZCP DCT - I'm back!!
2014 Guards Red 991 C2S 7MT - Gone. 2015 YMB/SS F80 M3 6sp - Gone 2011 Sapphire Black/Black E70 X5 M - Gone. 2010 Jerez Black/Black E90 M3 DCT -Gone- |
Appreciate
0
|
09-20-2014, 07:21 AM | #6 |
General
21117
Rep 20,741
Posts
Drives: 2021 911 turbo
Join Date: Jan 2012
Location: Montreal
|
1st gear is extremely short on the F8X DCT (to the point of being pretty useless IMO). It helps keeping things smooth in low speed low power conditions. However, if you mash it, it can get jerky.
|
Appreciate
1
|
09-20-2014, 07:36 AM | #7 |
Moderator
7515
Rep 19,368
Posts |
One thing you could do is try using Comfort mode while accelerating from a stop. It's very easy to change using the button on the console. Switching the Drivelogic mode may help too. Finally, you can just launch from second gear instead if you wish.
|
Appreciate
1
|
09-20-2014, 10:21 AM | #8 |
Major
328
Rep 1,450
Posts |
Middle position on the shift selector will dial it down a bit or put it in the fist (lowest or 1 bar) position for the shift and you will be fine. All sport mode in parking lots is a skittish place. Just leave engine on sport and all other comfort you have the enhanced sound but smooth ride in low speed areas.
|
Appreciate
0
|
09-20-2014, 10:25 AM | #9 |
Captain
157
Rep 965
Posts |
Yeah this happens sometimes and it's rather embarrassing. I've gotten good about immediately upshifting or backing off the throttle when I detect that it's happening
|
Appreciate
3
|
09-20-2014, 10:26 AM | #10 | |
Colonel
352
Rep 2,176
Posts |
Quote:
|
|
Appreciate
0
|
09-20-2014, 02:35 PM | #12 |
Private First Class
26
Rep 116
Posts |
|
Appreciate
0
|
09-20-2014, 02:38 PM | #13 |
Private First Class
26
Rep 116
Posts |
It is man specially taking off while everyone checking out your car Makes you look like you can't drive the car...
|
Appreciate
0
|
09-20-2014, 02:46 PM | #14 |
Private First Class
26
Rep 116
Posts |
|
Appreciate
0
|
09-20-2014, 06:51 PM | #17 |
Lieutenant
134
Rep 480
Posts |
Do not use S3/D3 mode. That is just too harsh and has no practical use. It is only there for the sake of proving fast shifts on paper. Even track drivers stay in S2.
There's no point in gaining 5 milliseconds faster shifting time if you're completely upsetting the entire chassis with the jolt, losing composure, traction, etc. |
Appreciate
0
|
09-23-2014, 01:13 PM | #18 |
Enlisted Member
3
Rep 46
Posts
Drives: Mineral White. DCT M4, S1000RR
Join Date: Sep 2014
Location: Middlesbrough, United Kingdom
|
As the bucking happens in 1st gear it has nothing to do with the shift settings though I agree in some situations setting 3 can upset the chassis. The problem is that the throttle response in Sport+ is a bit keen. If you hit the slightest bump when accelerating in first it causes a slight throttle adjustment. if the car decelerates inertia sends your foot forward you unconsciously back off and inertia sets up the on off situation which Kangaroos you down the road. I have found it is better if you drive with much more of a bent leg (i.e. closer to the throttle) but this is not ideal for me as I am too close to the wheel (Short arse).
|
Appreciate
0
|
09-23-2014, 10:45 PM | #19 |
Colonel
2594
Rep 2,683
Posts
Drives: '24 X7 M60i
Join Date: Jan 2014
Location: Scottsdale, AZ
|
Throttle induced oscillation. It was first noticed with the E39 M5.
Your foot moves ever so slightly back and forth that is hardly noticeable, but it gets into a rhythm with the throttle and causes the bucking.
__________________
Ex Stig
'25 M5 Touring (on the list, first slot) '24 X7 M60i '22 M5 CS - (sold) |
Appreciate
0
|
09-24-2014, 07:44 AM | #20 |
Useful Idiot
1330
Rep 1,777
Posts
Drives: My wife and kids insane.
Join Date: May 2011
Location: West Chester, PA
|
I experienced this first hand last night in my test drive and a light bulb went off in my head "I just read about this!".
The CA with me said as it happened: "Oh, no worries, the last person who drove this left the throttle in Sport +". We put it back down to sport and all was back to normal. I felt like such a noob driver, lol (which admittedly and comparatively to many I probably am). |
Appreciate
0
|
09-24-2014, 11:14 AM | #22 | ||
...
11827
Rep 15,400
Posts |
Quote:
"Mum, can you drive at all? I know this car wants to go, and doesn't do slow, but that's just so baaaaaaad" I've even stalled it once, though then I had forgotten it was on already. Thank god I was surrounded by M geeks and not my kids, the ripping from the last would've been worse.
__________________
Quote:
|
||
Appreciate
0
|
Post Reply |
Bookmarks |
|
|