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Dual-clutch and manual transmissions on their way out

By Faiming_low on 22 Apr 2017

Attached Image Just when we thought dual-clutch transmission is the way forward, someone from BMW reckons that the fast shifting transmission might be replaced with the conventional torque converter-based automatic.

As seen in Motor Authority, Peter Quintus, Vice President for Sales and Marketing at BMW M, said he expects manual and dual-clutch transmissions to be phased out in the coming years. Other than the obvious low demand for manual transmission, he explained that manuals have poor durability when paired with high-torque engines. Current heavy-duty manual transmissions that can handle high torque are, according to him, "heavy" and having shift quality that was "awful."

As for dual-clutch gearboxes, Quintus said the advantages they once offered over an automatic, such as their lighter weight and superior shift speed, were no longer significant. Like the manual gearboxes, they needed lots of beefing up to make them more durable for high-powered cars which in turns hurts the advantage the dual-clutch have over the normal torque converters ones.

Also in the article, Quintus also mentioned that he wasn’t sure if a manual transmission would even be offered on the next-generation M3 and M4 due later this decade.

Viewed: 5,173 times

Faiming_low
Written by Faiming_low
Since young, Fai Ming has always centered his life around cars. In fact his first word was 'car' and not 'mum' or 'dad'. Aren't kids cute?



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Still2016 Apr 23 2017 05:02 PM
Its matter of time before the concept of cars we know today would be forever changed in the not too distant future。
Watwheels Apr 23 2017 08:53 PM

I thought the gearbox will be phased out if we are going electric if electric cars are the future?

Sdf4786k Apr 24 2017 08:55 AM

I supposed the torque converter "slip" and losses has being improved over time. Just waiting for how much more efficient over DSG data...

Turboflat4 Apr 24 2017 11:33 AM

I supposed the torque converter "slip" and losses has being improved over time. Just waiting for how much more efficient over DSG data...

It's not about efficiency or performance. I believe DCTs are still better performing than torque converter autos in raw shift speeds. Certainly, DCTs give a much better feel when driven in manual mode than even the best torque converter auto.

 

The issue is longevity and reliability when faced with massive power. The best torque converters are better able to handle this than the best DCTs.

 

BMW gets transmissions from:

 

- Aisin (slushbox auto for FWD models like the 2-series active tourer)

- ZF (8 speed slushbox auto for RWD models like the M140i, my car)

- Getrag (7 speed DCT for RWD models like many M cars)

 

Mercedes uses:

- in house full auto transmissions (I think for most of the AMG "automatic" models, there's no true torque converter)

- Getrag 7 speed DCT for selected flagship models like the SLS and the AMG GT (my car). This Getrag DCT is different from the ones in the BMW M cars as it is rated for much higher torque figures.

 

Interestingly, the "feel" of a DCT transmission and whether it "behaves well" is more related to software quality than the physical construction - the Ferrari 458 uses the exact same 7 speed DCT found in the SLS and AMG GT, but the Ferrari transmission behaves poorly compared to those in the German cars - this is simply because the software is set up better in the German marques.

 

From personal experience, the 7 speed DCT in my AMG GT gives me all the satisfying 'clunks' of a manual in Sport+ mode (how I usually drive) but feels mostly like a slushbox in auto shifting comfort mode (what I use for warming up the car from a cold start). The ZF 8 speed slushbox on my M140i is a fantastic transmission and feels great in auto shifting mode but I just can't seem to get a feel for shifting it with the paddles. It shifts very fast (imperceptible shift times), but it just doesn't have a connected feel like the DCT in the other car.

 

Sorry, I now realise my post has become rather rambling, but the take home message here is that:

 

- the "feel" of a DCT vs a slushbox will always be different

- the "feel" and behaviour of even the same DCT will differ as a lot depends on software

- when it comes to humongous power and torque, slushboxes are far more capable of staying reliable than any other form of transmission.

 

To be honest, I think BMW is making these statements out of desperation more than anything else as they seem to be losing the high horsepower race to AMG. They also have access to the ZF slushboxes - which, while not really like the DCT in feel - are very, very good and very reliable in the face of high torque demands.

 

Finally, the Germans are way behind the curve when it comes to manuals. Surprisingly the Americans (real dark horses when it comes to automotive innovation) have some of the best manual transmissions capable of handling superlative torque demands - e.g. the Tremec trannies used in the Corvettes.

Aaronlkl Apr 24 2017 03:38 PM

It's not about efficiency or performance. I believe DCTs are still better performing than torque converter autos in raw shift speeds. Certainly, DCTs give a much better feel when driven in manual mode than even the best torque converter auto.

 

The issue is longevity and reliability when faced with massive power. The best torque converters are better able to handle this than the best DCTs.

 

BMW gets transmissions from:

 

- Aisin (slushbox auto for FWD models like the 2-series active tourer)

- ZF (8 speed slushbox auto for RWD models like the M140i, my car)

- Getrag (7 speed DCT for RWD models like many M cars)

 

Mercedes uses:

- in house full auto transmissions (I think for most of the AMG "automatic" models, there's no true torque converter)

- Getrag 7 speed DCT for selected flagship models like the SLS and the AMG GT (my car). This Getrag DCT is different from the ones in the BMW M cars as it is rated for much higher torque figures.

 

Interestingly, the "feel" of a DCT transmission and whether it "behaves well" is more related to software quality than the physical construction - the Ferrari 458 uses the exact same 7 speed DCT found in the SLS and AMG GT, but the Ferrari transmission behaves poorly compared to those in the German cars - this is simply because the software is set up better in the German marques.

 

From personal experience, the 7 speed DCT in my AMG GT gives me all the satisfying 'clunks' of a manual in Sport+ mode (how I usually drive) but feels mostly like a slushbox in auto shifting comfort mode (what I use for warming up the car from a cold start). The ZF 8 speed slushbox on my M140i is a fantastic transmission and feels great in auto shifting mode but I just can't seem to get a feel for shifting it with the paddles. It shifts very fast (imperceptible shift times), but it just doesn't have a connected feel like the DCT in the other car.

 

Sorry, I now realise my post has become rather rambling, but the take home message here is that:

 

- the "feel" of a DCT vs a slushbox will always be different

- the "feel" and behaviour of even the same DCT will differ as a lot depends on software

- when it comes to humongous power and torque, slushboxes are far more capable of staying reliable than any other form of transmission.

 

To be honest, I think BMW is making these statements out of desperation more than anything else as they seem to be losing the high horsepower race to AMG. They also have access to the ZF slushboxes - which, while not really like the DCT in feel - are very, very good and very reliable in the face of high torque demands.

 

Finally, the Germans are way behind the curve when it comes to manuals. Surprisingly the Americans (real dark horses when it comes to automotive innovation) have some of the best manual transmissions capable of handling superlative torque demands - e.g. the Tremec trannies used in the Corvettes.

 

Very well written bro!

Turboflat4 Apr 24 2017 04:19 PM

Very well written bro!

 

Thanks bro, much appreciated. :)

lukeusesforce Apr 25 2017 11:36 AM

I've only ever driven 2 (BnB) cars equipped with DCTs, but I felt that more than reliability or shift speed, the low-speed feel can be quite a turn off.

In stop-start traffic and in carparks, those DCT cars are very lurchy and jerky (presumably this is the clutches engaging and disengaging.) There's also a feel of the engine having to work a bit (again I presume this is the clutch being slipped for better smoothness.) The feeling is a bit "sian-sian".

Maybe the DCTs in performance cars aren't like this, but being a family man I don't need lightning shifts, so I don't think I will take a DCT in my next car, thanks. I'd rather go back to a slushbox...

Ake109 Jul 01 2017 01:21 AM

It's not about efficiency or performance. I believe DCTs are still better performing than torque converter autos in raw shift speeds. Certainly, DCTs give a much better feel when driven in manual mode than even the best torque converter auto.

 

 

Another ding against DCTs is that in unusual situations like reversing turn up a hump, it doesn't have the torque multiplier effect of a slushbox so it can only do 2 things - rev and clutch slip. Programming that to cater to all situations is probably a herculean task. The slushbox can just wind up the torque and get you up that hump but the DCT needs to balance the rev and the slip without knowing what the driver wants exactly or how the angle of the hump is going to change in the next split second.

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