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      06-16-2017, 10:01 AM   #1
MZWIE
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DCT & SPORT+& HIGH REVS = rough shifts

The difference between SPORT and SPORT+ for DCT shifts is big. In SPORT shifts are nice and crisp.

Currently not only are the shifts teeth rattling but also very embarrassing when having passengers. Every thinks there is something wrong with the transmission.

In SPORT+ it feels like a first generations SMG. I'm sure there must be a way to maintain fast shifts without the bang-bang.

I'm thinking some electronic value could be adjusted. Any ideas
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      06-16-2017, 11:14 AM   #2
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That's the point of sport+. I wouldn't change a thing. It the passengers fault for never being in a sports car or in a car with F1 style performance.
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      06-16-2017, 11:35 AM   #3
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F1 cars don't shift with like the DCT. I've been very close to them. All you hear with F1 is rev pitch change.

The DCT has a noticeable disengage and re-engage. When re-engaging feels like a teenager learning to drive a manual tranny.
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      06-16-2017, 11:46 AM   #4
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Tip: A louder exhaust system would make high rev shifting noises in S+ feel less wrong.
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      06-16-2017, 12:47 PM   #5
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Sorry, but it's not a sound thing. It's the very loud thump that you can feel. The thump is so load that it feels like something has broken.

Same as with the SMG. It always sounded like a gorilla pounded the side of the car with a 2x4.
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      06-16-2017, 01:09 PM   #6
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I love it and its even more brutal on the M5. Fricking awesome.
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      06-16-2017, 02:08 PM   #7
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Quote:
Originally Posted by MZWIE View Post
The difference between SPORT and SPORT+ for DCT shifts is big. In SPORT shifts are nice and crisp.

Currently not only are the shifts teeth rattling but also very embarrassing when having passengers. Every thinks there is something wrong with the transmission.

In SPORT+ it feels like a first generations SMG. I'm sure there must be a way to maintain fast shifts without the bang-bang.

I'm thinking some electronic value could be adjusted. Any ideas
Bingo BMW need to update the Software like the old PPK for the 135

The PPK fix the DCT on the 135i big time!!!!

The PPK certainly improved the throttle lag with my DCT. Just in "D" there is not much difference from pre-PPK that I can tell, but I rarely drive in "D". With the sport button on (how I normally drive) there are some extra burbles and pops and it just feels a little more "responsive". If you put the shifter over and put it in S-mode the burbles on deceleration are crazy (good).

Last edited by AGM2; 06-16-2017 at 02:17 PM..
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      06-16-2017, 02:54 PM   #8
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I think Bmw has artificial kickbacks in sport+ mode. It doesn't have to be that way. You can be quick and smooth - PDK does it very well.
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      06-18-2017, 12:13 PM   #9
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Buy a Camry.
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      06-19-2017, 11:57 AM   #10
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Quote:
Originally Posted by mrcheezle19 View Post
Buy a Camry.
There is always someone who is totally useless.

I asked a legitimate question. I have driven most manufacturers' DCT's. BMW, Porsche, Ferrari, etc.

None are this violent. They all shift lightning quick.

Last edited by MZWIE; 06-19-2017 at 12:14 PM..
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      06-19-2017, 12:36 PM   #11
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Quote:
Originally Posted by MZWIE View Post
There is always someone who is totally useless.

I asked a legitimate question. I have driven most manufacturers' DCT's. BMW, Porsche, Ferrari, etc.

None are this violent. They all shift lightning quick.
It's a light-hearted joke. I've always felt BMW DCT shift that way especially in sport+ maybe reflash your dct software with M4 GTS flash and see if you like that better?
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      06-21-2017, 03:34 PM   #12
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On a side note.
I've just returned from my second M Tour Day at one of the driving schools nearby. I've asked the most pro instructor about manual vs DCT and he said DCT all the way (also showed me why at the track). But to the point, I've asked about DCT upsetting car's balance during cornering and we tested it extensively on the track together and it turns out that even in Sport+ ECU limits those hard shifts in corners - it was smooth as butter all the time when he changed mid corner but on straight line from standstill it was felt hard. That's actually very clever by BMW and makes me go DCT 100%.
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      06-21-2017, 03:51 PM   #13
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Cool, didn't know that!
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      06-22-2017, 02:56 AM   #14
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Quote:
Originally Posted by MZWIE View Post
The difference between SPORT and SPORT+ for DCT shifts is big. In SPORT shifts are nice and crisp.

Currently not only are the shifts teeth rattling but also very embarrassing when having passengers. Every thinks there is something wrong with the transmission.

In SPORT+ it feels like a first generations SMG. I'm sure there must be a way to maintain fast shifts without the bang-bang.

I'm thinking some electronic value could be adjusted. Any ideas
This really annoys me too.

Basically it's the gearbox calibration strategy employed by BMW to simulate something different to make uneducated drivers think they're getting something extra, when in fact, it's just not nice.

In sport mode the car shifts quickly and smoothly, without the 'donkey kick' as I like to call it, but sadly when you go into sport+ to reduce DSC interventions (and have a bit more fun), this 'donkey kick' comes with it, to me it makes the car undriveable and I generally avoid using it. Sport or DSC off is really the only options I enjoy.

From a stability and safety point of view, sport+ is also it's own worst enemy. This gearbox calibration cuts torque and dumps it back in after a delay, very violently, and the sudden torque saturates the tyres instantly and causes a loss of traction with fires the DSC system into action to cut power. I would actually argue, full throttle down an undulating road, the car will be faster in sport, than sport+. And in the wet, sport+ is like a chocolate teapot, unless you like staring at a flashing DSC light all the time.

A friend of mine has a Cayman S (981 gen), and has the same issue, although it's not quite as bad as the BMW strategy.
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      06-22-2017, 09:06 AM   #15
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Quote:
Originally Posted by MZWIE View Post
There is always someone who is totally useless.

I asked a legitimate question. I have driven most manufacturers' DCT's. BMW, Porsche, Ferrari, etc.

None are this violent. They all shift lightning quick.
If you like Sport, why not use it with one press of MDM? Same thing if you are on Chassis and Driveline.... Just press the go button harder since your throttle mapping wont be the same as Sport + though.
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      06-22-2017, 03:32 PM   #16
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STEELIUS

Couldn't agree more....I like the "donkey kick". So back to my original question. It is obviously a code issue. We need to find out how to adjust this.

I don't like the idea of having DSC totally off. Never know what happens on any given day.
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      06-22-2017, 04:37 PM   #17
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Quote:
Originally Posted by Steelius View Post
This really annoys me too.

Basically it's the gearbox calibration strategy employed by BMW to simulate something different to make uneducated drivers think they're getting something extra, when in fact, it's just not nice.

In sport mode the car shifts quickly and smoothly, without the 'donkey kick' as I like to call it, but sadly when you go into sport+ to reduce DSC interventions (and have a bit more fun), this 'donkey kick' comes with it, to me it makes the car undriveable and I generally avoid using it. Sport or DSC off is really the only options I enjoy.

From a stability and safety point of view, sport+ is also it's own worst enemy. This gearbox calibration cuts torque and dumps it back in after a delay, very violently, and the sudden torque saturates the tyres instantly and causes a loss of traction with fires the DSC system into action to cut power. I would actually argue, full throttle down an undulating road, the car will be faster in sport, than sport+. And in the wet, sport+ is like a chocolate teapot, unless you like staring at a flashing DSC light all the time.

A friend of mine has a Cayman S (981 gen), and has the same issue, although it's not quite as bad as the BMW strategy.
So its the transmission shifting the car and not the lack of DSC that is causing the car to be unstable at the limit?
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      06-22-2017, 06:43 PM   #18
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Quote:
Originally Posted by lax01 View Post
Quote:
Originally Posted by Steelius View Post
This really annoys me too.

Basically it's the gearbox calibration strategy employed by BMW to simulate something different to make uneducated drivers think they're getting something extra, when in fact, it's just not nice.

In sport mode the car shifts quickly and smoothly, without the 'donkey kick' as I like to call it, but sadly when you go into sport+ to reduce DSC interventions (and have a bit more fun), this 'donkey kick' comes with it, to me it makes the car undriveable and I generally avoid using it. Sport or DSC off is really the only options I enjoy.

From a stability and safety point of view, sport+ is also it's own worst enemy. This gearbox calibration cuts torque and dumps it back in after a delay, very violently, and the sudden torque saturates the tyres instantly and causes a loss of traction with fires the DSC system into action to cut power. I would actually argue, full throttle down an undulating road, the car will be faster in sport, than sport+. And in the wet, sport+ is like a chocolate teapot, unless you like staring at a flashing DSC light all the time.

A friend of mine has a Cayman S (981 gen), and has the same issue, although it's not quite as bad as the BMW strategy.
So its the transmission shifting the car and not the lack of DSC that is causing the car to be unstable at the limit?
The car is very stable at high speed with the DCT.
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      06-22-2017, 06:47 PM   #19
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Quote:
Originally Posted by David1 View Post
The car is very stable at high speed with the DCT.
I'm saying...he's turned off all the driving aids and he thinks the slightly faster shifts are causing the car to be less poised/balanced (as opposed to the lack of driving aides making the car less poised/balanced)
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      06-22-2017, 07:35 PM   #20
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I'm just finishing break-in and will be hitting the track shortly in the M2 and will experience this for myself.

If I'm understanding the "issue" and donkey-kick is a good analogy, Porsche PDK-S does this too in sport mode as it approaches the rev limit under WOT. It's particularly severe in the GT3 but and a bit less pronounced in the GT3 RS. Note: PDK-S is different than PDK which doesn't do this nearly as badly. I believe it's done to minimize the shift time even further. Feature not a defect.
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      06-23-2017, 01:26 AM   #21
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Unfortunately you won't be able to turn it off or change it, as it's part of the cars fundamental transmission software. You'd need the development tools BMW have to create a new transmission calibration... it's massively complicated.
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      06-23-2017, 01:34 AM   #22
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Just try a back to back test.

Try changing gear in Sport and Sport+ at full throttle, see which one destabilises the car. Take note of how much DSC lamp flash you get in each too.

Maybe I'm just a bit cynical but subjectively the shifts in sport+, to me, don't feel any faster, or even fast enough to warrant the donkey-kick they bring... they just upset the car.

Just my thoughts
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