Throttle lag on chassis upset

dashboy · 12-21-2018, 03:53 AM

I noticed an issue since owning my 2012 135i DCT from new.
Out here in Dubai, we have alot and I mean alot of speed bumps. Some that you need to come to a full stop as they are F$&king mountains and others that are 40kph accessible just before a roundabout.

The issue is when the chassis gets upset over the speed bump it takes a few seconds for the throttle to kick in and accelerate. The request for acceleration was just after the bump.

I can count 2 seconds easily before the RPM starts to climb.

I believe it didn't matter id the DTC was on or off.

Any fix for this?

bbnks2 · 12-21-2018, 08:16 AM

Quote:

Originally Posted by dashboy

I noticed an issue since owning my 2012 135i DCT from new.
Out here in Dubai, we have alot and I mean alot of speed bumps. Some that you need to come to a full stop as they are F$&king mountains and others that are 40kph accessible just before a roundabout.

The issue is when the chassis gets upset over the speed bump it takes a few seconds for the throttle to kick in and accelerate. The request for acceleration was just after the bump.

I can count 2 seconds easily before the RPM starts to climb.

I believe it didn't matter id the DTC was on or off.

Any fix for this?

Yes turn traction control off

Soterios · 12-21-2018, 09:41 AM

It's probably the traction control or stability control. I always turn both off every time I get in the car (Press and hold the traction control button for a few seconds)

The Wind Breezes · 12-21-2018, 03:04 PM

As the last guy mentioned you have to hold the button down for a while. Be cautious. Someone asking this question probably doesn't have business disabling DSC in the first place.

Winn.Nguyen · 12-22-2018, 12:16 AM

Try doing it with your AC off. Our DCT cars behave differently with the AC on. I only experience throttle response issues every time it's on when I'm driving in the city. But with it off the car drives like a dream.

drwillb · 12-22-2018, 08:49 AM

Dubai + AC off..........gotta think that one through. Probably ok in the evening. Probably not so good at noon.

Turn off traction control: 1 push of the traction button. Try it that way first. If that doesn’t work, then turn off stability control: long hold of the same button.

Be warned: stability control has already probably saved your ass many times and you never even noticed. This feature can act at a very subtle level if you are approaching stupid levels of driving at a slow rate. You only really notice it when you are aggressively driving.

Get on a track with an instructor and see what the car can do. Yas Marina is outstanding.

low135 · 12-22-2018, 12:59 PM

Pretty common complaint I hear from dual clutch trans owners of many manufacturers. I know these aren't tunable like other cars but can he flash a different cars tune to help?

zx10guy · 12-22-2018, 02:15 PM

Here's my thread on what was pretty much the fix for this throttle lag. And I've tried everything.

https://www.1addicts.com/forums/show....php?t=1402323

I do have to say when I brake hard and then get on the gas again, there is a significant lag still present. It doesn't happen very often but still does on occasion. But the fix done to my car which is now a couple of years has been the magic bullet of me finally being able to enjoy this car.

smrtypants44 · 12-22-2018, 03:49 PM

I have the same problem-coasting to a near stop (like at a yield sign) then trying to go again, it takes a couple of seconds to engage. Dont think its related to traction control in any way- just probably catching the clutches off guard.

Gizmo135i · 12-22-2018, 06:58 PM

You may want to try having a dealer update the software in the car, and reset all of the DCT and engine adaptations. There is a BMW bulletin for it and the update seems to help smooth things out.

Some people, myself included claim notice an improvement with a custom MHD tune. It may just be that I’ve gotten used to the DCT, or it may be that I drive in manual mode 99% of the time, but I feel like the trans overall shifts better, especially compared to when I had a JB4 installed.

Even though the DCT is the “auto” option on these cars, realize that it is not an automatic with a torque converter, and it does take a moment for the clutch to engage, if your not used to it it could be a little awkward to drive.

12-21-2018, 03:53 AM	#1
dashboy New Member 3 Rep 12 Posts Drives: 135i M-Sport DCT Join Date: Jun 2012 Location: Dubai iTrader: (0)	Throttle lag on chassis upset I noticed an issue since owning my 2012 135i DCT from new. Out here in Dubai, we have alot and I mean alot of speed bumps. Some that you need to come to a full stop as they are F$&king mountains and others that are 40kph accessible just before a roundabout. The issue is when the chassis gets upset over the speed bump it takes a few seconds for the throttle to kick in and accelerate. The request for acceleration was just after the bump. I can count 2 seconds easily before the RPM starts to climb. I believe it didn't matter id the DTC was on or off. Any fix for this? __________________ 2012 135i M-Sport Coupe DCT ~ Marrakesh: Metallic Brown \| Remus Sport Quad Axle Back \| Koni Sport with Swift Spec-R \| JB4 \| CP Catless DP \| Wagner FMIC \| FTP IC Pipes \| K&N Filter \| P Zero 10mm wider \| LED Angle Eyes \| All LED interior-exterior lights \| BMW Performance Pedals
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12-21-2018, 09:41 AM	#3
Soterios BXR 575 Rep 636 Posts Drives: 2012 135i Join Date: Jun 2018 Location: Missouri iTrader: (0)	It's probably the traction control or stability control. I always turn both off every time I get in the car (Press and hold the traction control button for a few seconds) __________________ 2012 135i M Sport Alpine White
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12-21-2018, 03:04 PM	#4
The Wind Breezes Lieutenant Colonel 912 Rep 1,850 Posts Drives: 135i N55 DCT Join Date: Apr 2015 Location: USA iTrader: (0)	As the last guy mentioned you have to hold the button down for a while. Be cautious. Someone asking this question probably doesn't have business disabling DSC in the first place.
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12-22-2018, 12:16 AM	#5
Winn.Nguyen Private First Class 85 Rep 137 Posts Drives: BMW Join Date: Jan 2016 Location: Portland iTrader: (0)	Try doing it with your AC off. Our DCT cars behave differently with the AC on. I only experience throttle response issues every time it's on when I'm driving in the city. But with it off the car drives like a dream.
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12-22-2018, 08:49 AM	#6
drwillb BMW Fan 289 Rep 838 Posts Drives: e30 M3, e30 M3, e46 M3 Join Date: Aug 2008 Location: northern NJ iTrader: (4)	Dubai + AC off..........gotta think that one through. Probably ok in the evening. Probably not so good at noon. Turn off traction control: 1 push of the traction button. Try it that way first. If that doesn’t work, then turn off stability control: long hold of the same button. Be warned: stability control has already probably saved your ass many times and you never even noticed. This feature can act at a very subtle level if you are approaching stupid levels of driving at a slow rate. You only really notice it when you are aggressively driving. Get on a track with an instructor and see what the car can do. Yas Marina is outstanding. Last edited by drwillb; 12-22-2018 at 08:57 AM..
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12-22-2018, 12:59 PM	#7
low135 Banned 2211 Rep 1,285 Posts Drives: E88 135i Join Date: Apr 2015 Location: Clearwater iTrader: (0)	Pretty common complaint I hear from dual clutch trans owners of many manufacturers. I know these aren't tunable like other cars but can he flash a different cars tune to help?
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12-22-2018, 03:49 PM	#9
smrtypants44 Captain 518 Rep 895 Posts Drives: 2017 440i Join Date: Jul 2015 Location: Tulsa, OK iTrader: (2)	I have the same problem-coasting to a near stop (like at a yield sign) then trying to go again, it takes a couple of seconds to engage. Dont think its related to traction control in any way- just probably catching the clutches off guard. __________________
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12-22-2018, 06:58 PM	#10
Gizmo135i Second Lieutenant 116 Rep 264 Posts Drives: 135i n55 Join Date: May 2016 Location: Park Ridge NJ iTrader: (0)	You may want to try having a dealer update the software in the car, and reset all of the DCT and engine adaptations. There is a BMW bulletin for it and the update seems to help smooth things out. Some people, myself included claim notice an improvement with a custom MHD tune. It may just be that I’ve gotten used to the DCT, or it may be that I drive in manual mode 99% of the time, but I feel like the trans overall shifts better, especially compared to when I had a JB4 installed. Even though the DCT is the “auto” option on these cars, realize that it is not an automatic with a torque converter, and it does take a moment for the clutch to engage, if your not used to it it could be a little awkward to drive.
	Appreciate 0 Quote