# BMW Exec confirms DCT Transmissions days are numbered



## Autoputzer (Mar 16, 2014)

The BMW executive didn't say DCT's were going away. The author of the article said that. The BMW executive did say that automatics are getting better (true), and manuals are likely going away (true).

A lot of manufacturers are putting DCT's in mundane cars (VW GDI's, Hyundai Tucson compact SUV's, etc.) A DCT eliminates the torque converter and the inherent losses they have. DCT's aren't great for stop and go traffic. The start off is a little jerky. 

The torque multiplication of a torque converter is great for towing... and drag racing. The amount of energy transferred by a shaft is torque x rotation speed. Torque converters translate slip into torque multiplication:

Output Torque = (eta) x (Input Torque) x (Input RPM) / (Output RPM) 

(eta) is the efficiency of a torque converter, usually above 0.9 now. But, if the output RPM is half the input RPM, the output torque is almost twice the input torque. That's awesome when you're pulling a trailered, 27- foot Grady White up a boat ramp. But, I'm not going to be towing with an M2 or a 911, or even a Hyundai Tucson.

I was at a BMW event a few years ago where an M product manager gave a presentation. He said that "the horsepower wars are over," that future M development will focus on lighter weight and better vehicle dynamics (read that as xDrive for at least the big M cars). But, the big M cars aren't really sports cars in the classic sense. They're more muscle cars, but really good ones. Admittedly, an AWD muscle car could take advantage of torque multiplication.

I've been to a bunch of Advanced M Schools. When a M car ends up on the side of the track, it's usually due to a DCT failure, and it's usually a big M car (M5/6). I broke a DCT on an M5, or more accurately it broke while I was driving it. The second most common for retirement was brakes (solved by CCB's on the M3/4/5/6's used at the school), followed by tires. M2's were having brake issues in heavy track use, rotor warping and pad material deposits on the rotors.


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## gkr778 (Feb 8, 2013)

Autoputzer said:


> The BMW executive didn't say DCT's were going away. The author of the article said that. The BMW executive did say that automatics are getting better (true), and manuals are likely going away (true).


Thank you Autoputzer. You are correct on all counts! Magna-Getrag, the supplier of DCT to BMW, offers a 7-speed version that's capable of handling 750 Nm of torque reliably (7DCL750).

In addition to incorrectly attributing the assertion "[DCT] still aren't completely capable of handling the power output of their highly-tuned engines" to Mr. Quintus, this article by Caleb Jacobs also used the nonsensical phrase "single clutch automatics".

If Jacobs' writing is representative of _The Drive_, this publication should not be taken seriously.


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## Autoputzer (Mar 16, 2014)

gkr778 said:


> Thank you Autoputzer. You are correct on all counts! Magna-Getrag, the supplier of DCT to BMW, offers a 7-speed version that's capable of handling 750 Nm of torque reliably (7DCL750).
> 
> In addition to incorrectly attributing the assertion "[DCT] still aren't completely capable of handling the power output of their highly-tuned engines" to Mr. Quintus, this article by Caleb Jacobs also used the nonsensical phrase "single clutch automatics".
> 
> If Jacobs' writing is representative of _The Drive_, this publication should not be taken seriously.


Good catch on the "single clutch automatics." Yeah, the writer is clueless as well as being a BS artist.


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## gkr778 (Feb 8, 2013)

Since The Drive article is BS, perhaps a Bimmerfest admin article can correct the inaccurate title of the OP?


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## namelessman (Dec 23, 2004)

My recollection is that Honda did put a TC on DCT to smooth out the jerky startup. Is that TC + DCT setup used in Acura TLX?


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## gkr778 (Feb 8, 2013)

namelessman said:


> My recollection is that Honda did put a TC on DCT to smooth out the jerky startup. Is that TC + DCT setup used in Acura TLX?


You got it! In addition to TLX, Acura ILX also the same 8-speed DCT with torque converter.

The unit was designed and engineered in-house by Honda Motor Co.; the torque converter is supplied by Cardington Yutaka Technologies, Inc.


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