Bucking while accelerating - DCT?

[brianeck]

Hmm. Similar issue in a manual a few times. I do actually believe it has something to do with the traction control though, as now my M2 is sport+ all around with the TC fully off and I don't seem to notice it ever. It is always within 5 minutes of me starting the car so I feel like its some kind of weird calibration event type thing.

Obviously we have different transmissions but your problem sounds very similar. The DSC light isn't a great indicator as it doesn't come on all the time when I can feel the power being limited.

[Blksnowflake]

Not the car, it's your operation of the DCT. This car's DCT is more sensitive than my Evo X but I've come to realise that the DCT likes to be driven with direct intention. If you just want to cruise around spirited driving then the DCT on 2 and throttle on sport will suffice, if the DCT is on three and throttle sport or sport plus and you half ass the throttle....bronco ride.
In this setting if you give gas then you better be ready to effing go, and go for real, not to the next light....

This has been discussed ad nauseam in a few threads, do a search.

[sameh]

Originally Posted by Blksnowflake

Not the car, it's your operation of the DCT. This car's DCT is more sensitive than my Evo X but I've come to realise that the DCT likes to be driven with direct intention. If you just want to cruise around spirited driving then the DCT on 2 and throttle on sport will suffice, if the DCT is on three and throttle sport or sport plus and you half ass the throttle....bronco ride.
In this setting if you give gas then you better be ready to effing go, and go for real, not to the next light....

This has been discussed ad nauseam in a few threads, do a search.

I've had my E92 for 5 years and put 80K miles on it and it was DCT, so unless F80 DCT is very different than my old 2011 E92 I doubt that I need more seat time to figure out how to drive DCT. But I know what you're talking about, DCT requires commitment in acceleration to figure out what you want to do and it does detect foot hesitation. Again doubt that's what it was.

[Vigilant]

Originally Posted by Blksnowflake

Not the car, it's your operation of the DCT. This car's DCT is more sensitive than my Evo X but I've come to realise that the DCT likes to be driven with direct intention. If you just want to cruise around spirited driving then the DCT on 2 and throttle on sport will suffice, if the DCT is on three and throttle sport or sport plus and you half ass the throttle....bronco ride.
In this setting if you give gas then you better be ready to effing go, and go for real, not to the next light....

This has been discussed ad nauseam in a few threads, do a search.

I agree. D2/S2 and sport setting for throttle is the sweet spot.

[brianeck]

If its the DCT then how do I have a similar problem. I'm 6MT, and this is not a shifting issue.

[Vigilant]

The nannies can be intrusive, and it sounds like a little pedal modulation may be helpful. There have been previous threads on this issue. If it is of concern, maybe a visit to your local dealer may be in order.

[brianeck]

Originally Posted by Vigilant

The nannies can be intrusive, and it sounds like a little pedal modulation may be helpful. There have been previous threads on this issue. If it is of concern, maybe a visit to your local dealer may be in order.

There are a lot of different computers competing to do many different things in the cars. . .

My bucking is in 1st gear 6MT after a smooth engagement of the gear, at like 1/3-1/2 throttle. It's nothing like a poorly slammed shift into 2nd or something which can induce similar bucking, its after a nice easy relaxed shift, and again I've never noticed it 5 minutes or longer after starting the car.

[M4LessThan3]

I cannot help but jerk the car (M4) quite a bit when I accelerate from the straight line in Sport Plus mode.

Some information:
The car is brand new.
Settings: Sport Plus, Sport, Sport, S3, DSC

How much would switching from DSC to MDM help with this? I also know that I must not be pressing the accelerator correctly for this to happen.

Experienced drivers of the M4, any advice would be greatly appreciated.

Thank you!

[erind]

Drive the car hard if you put it on sport+. That will do the trick.

[M4LessThan3]

Originally Posted by erind

Drive the car hard if you put it on sport+. That will do the trick.

Yeah I noticed it is much smoother if I go hard. But sometimes I just want to hear the beautiful noise in sport + when I'm accelerating.

I guess that's not possible

[antych]

Unlike what you will hear from MT fanboys, DCT actually takes some effort and practice to drive well. My experience thus far is that in sport mode, you either need to be really gentle with the throttle, or really sure you want to go fast. Anything in between, any hesitation, will likely lead to jerkiness. If you just got the car, be patient and get a good feel for the accelerator. I bet the problem will go away as you get used to it.

[antych]

Originally Posted by M4LessThan3

Yeah I noticed it is much smoother if I go hard. But sometimes I just want to hear the beautiful noise in sport + when I'm accelerating.

I guess that's not possible

sport and sport+ sound the same, so you can take it down a notch and make the accelerator less sensitive.

[M4LessThan3]

Originally Posted by antych

sport and sport+ sound the same, so you can take it down a notch and make the accelerator less sensitive.

Really? Sport+ seems more aggressive to me. Or is it just all in my head..

[M4LessThan3]

Originally Posted by antych

Unlike what you will hear from MT fanboys, DCT actually takes some effort and practice to drive well. My experience thus far is that in sport mode, you either need to be really gentle with the throttle, or really sure you want to go fast. Anything in between, any hesitation, will likely lead to jerkiness. If you just got the car, be patient and get a good feel for the accelerator. I bet the problem will go away as you get used to it.

Definitely agree with that. It'll probably go away over time.

Thanks for your input!

[jeff4598]

Could not be very smooth in my DCT e90 until I got Dinan and now (way better) BPM DCT software.

[jc05e46m3]

Originally Posted by antych

sport and sport+ sound the same, so you can take it down a notch and make the accelerator less sensitive.

This. /end thread

[SaMaster14]

I think the issue is the transmission in S3 maybe? S2 seems to be a sweet spot.

The DCT has a learning curve and can be jerky if you don't shift it properly.


Or, if you really just want the sound, get the BMS CANFLAP module (or something similar) and you can keep the exhaust valves open all of the time (even in Sport+ they are closed if not under WOT)

[antych]

Originally Posted by SaMaster14

I think the issue is the transmission in S3 maybe? S2 seems to be a sweet spot.

You're right that S2 is the sweet spot, but S3 doesn't lead to jerkiness, which happens in 1st gear only anyway. S3 will make gear changes so aggressive that they may upset the chassis - different problem.

[erind]

Originally Posted by antych

sport and sport+ sound the same, so you can take it down a notch and make the accelerator less sensitive.

^This. The sound is the same and the car is less agressive.

[erind]

When you put it in sport+ the car is like this so if you go slow it will confuse the transmission. Just put it in sport and S2.

[bwu]

If you just got the car, i agree with starting with sport w/ s2. Later when you realize you need more power bcuz it gets boring, sport+ w/ s3 is the way to go. I can't go back down to anything else now

[VDBimmer]

Originally Posted by M4LessThan3

Really? Sport+ seems more aggressive to me. Or is it just all in my head..

Not sure if you mistaked for feel, what he meant was the sound of the car when in either sport or sport+ are very close to the same. The feel though is a bit more aggressive in Sport+.

Basically, if you want to drive the car not too aggressively but still want the nice sound of the open exhausts then drive in sport not sport plus (you will hear its as nice or very close to as nice as sport+ and the car won't be 'as' jerky as in sport+)

Also change the shifting to 1 bar instead of 3 which will make the shifts a bit late but will reduce jerkiness a lot