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Has DCT technology itself improved over the years?

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6K views 20 replies 7 participants last post by  DoubleThumper 
#1 ·
Hi Everyone,

Looking into buying a DCT version of the AT and I’m considering both 2016 and 2018 options. Of course ‘16 models can be found at a 1.5k discount compared to the ‘18 versions.

I’m not that interested in riding modes and all the electronics of the ‘18 model, but I’m now wondering whether the DCT technology materially improved in its AT second generation. Anyone that tried both?

I can’t manage to find a 2018 DCT tricolor in my region, and I got fixated with that color :).

Thanks
 
#7 ·
They have improved the algorithms for the down shifting beginning in 2018. The throttle by wire now blips the throttle to match the rpm for the gear changes which reduces shock loading the transmission and makes a smoother downshift. In 2020 the shifting has improved for cornering as the ECU can sense lean angles and deceleration more accurately. I read an article by one of the engineers from Honda who was involved in development of the DCT. He says they are always working on improvements to the operation of the DCT. The low speed throttle response also seems better to me with the 2019 AT vs the older 2016-17 models without throttle by wire.
 
#9 ·
"The throttle by wire now blips the throttle to match the rpm for the gear changes which reduces shock loading the transmission and makes a smoother downshift. "
I believe they implemented the blipping to make the downshifts even smoother but not "match rpm".
As you may know, DCT always pre-engages the next gears up or down and there is absolutely no need to rev-match- the gears have already meshed together.

That said, every year DCT is improved from year to year and I noticed that every other year they have added extra features.
Like already noted, the '16 to '18 was where many new features were added but it is hard to translate those into dollar for dollar worth.
YMMV (your mileage may vary) as they say, but I think they are worth the prices difference, today. No one knows how well the '16 prices will hold up :)
 
#14 ·
This is directly from the Honda Engineer in charge of the DCT development:
What do you think has been the biggest single improvement throughout the decade of DCT?

It’s not possible to pinpoint one particular change as most important. That’s because the system has evolved consistently over the decade, with different changes being introduced that not only improved DCT itself, but also made it bring out more and more the different riding characteristics required of each different model.

One of the first big steps was the automatic return to Automatic mode if you used the manual triggers as an override to select a gear. It’s a lot of programming to make the return to automatic as intuitive as possible, because you have to calculate the riding situation and therefore the rider’s intention – was it a downshift coming into a tight corner, a downshift to overtake on a straight road, etc. It’s not just a question of returning the system to Automatic after a certain number of seconds.

Later, we refined the way that the throttle blips on the downshift to accurately match the revs and make those shifts really smooth. These changes involved a lot of synchronization with the PGM-FI fuel injection controls.

We also introduced the ‘Adaptive Clutch Capability Control’ which uses the electronic control of the DCT system to ‘slip’ the clutch a little when the throttle position is changed initially from a fully closed or fully opened position. That really helped smooth out the bike behaviour.
 
#15 ·
Good catch!
But I wonder what the article meant by that statement "match the revs" did he really say that?
Most likely just another mistake in translation.
.
It doesn't take a genius to understand the basic function of gear changes within DCT.
All the odd and even gears are turning at the same rpm at all times, by design.

Machine Engineering Gear Automotive engine part Transmission part
 
#21 ·
When I think of the "DCT" subsystem, it includes:
  • The gearbox,
  • The sensor array,
  • And the firmware (the algorithm, or "logic").

Each play a critical role in the total functionality, behaviour and performance of the DCT. The DCT cannot function without any one of these components. Arguably, a fourth (4th) component can be included: The processing component. If the processing (including memory) does not get "clean" access to a [reliable] electrical source, then the logic will behave erratically.
 
#20 ·
The gearbox on the DCT functions identically to a std. gearbox using gears in constant mesh and engaging and disengaging gear dogs with the gears sliding on the shaft. On 2018+ models the throttle is automatically blipped on downshifts to unload the gears and allow smoother dis-engagement/ engagements of the gear dogs. That is what I am saying. Earlier models DCT did not automatically blip the throttle to do this and the gear changes could be rougher. That is what the Honda Engineer is also talking about.
 
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