Does anyone drive a dual clutch automatic?

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  1. MoodyBlues

    MoodyBlues - Crazy peacock person -

    Just wondering if anyone here has a vehicle with a dual clutch transmission. Frankly, I don't get it. I don't understand the thinking behind them and I don't understand why anyone would want them instead of a true manual transmission. :confused: Here's a bit of info from BMW:

    I don't get it--why would I want TWO clutches? My manual transmission vehicle is perfectly capable of shifting through all of its gears with one clutch. And why, with not one but two clutches, would I drive in automatic mode?

    If anyone here actually has a dual clutch vehicle, would you mind posting pics of its interior setup? And let me know if you like driving it. Everyone else feel free to toss in your thoughts, too!

  2. jhawkkw

    jhawkkw Chinchillin' Moderator

    I'm not really sure either, but it seems that most 7 speed manuals tends to come with these dual clutch systems. Seems like a nuisance on the surface to me.
  3. dibblebill

    dibblebill Well-Known Member

    How do yo udefine interior setup? The gearshift lever? I like my dual-clutch automatic.

    I've got a 2012 Jetta TDI Premium w/ Nav and the DSG transmission. the DSG supposedly shifts as fast as, if not faster than, a race car driver on manual. its a load of fun in 'manual' mode, but switches back to automatic easily for tedious city driving.
  4. MoodyBlues

    MoodyBlues - Crazy peacock person -

    The controls themselves. Are there actual clutch pedals, like on a manual transmission vehicle? Or are the two clutches engaged by hand? Or what? And, yes, I'd like to see a closeup of the gearshift lever.

    Good to know.

    But as I understand it, it's not truly manual, right? From WikiPedia:

    Just wondering, too, if you've driven real stick shift vehicles or if you came to dual clutch directly from automatic.

    FWIW, I learned to drive on an automatic, and drove those for the first few years. I had what can only be described as a traumatic initial experience driving a stick shift during that time, but later wanted to give it another try. When I did--and actually had a manual transmission that didn't have one of its gears missing--I fell in love. That was about 30 years ago and I've never looked back. So I'm basically just curious about this whole dual clutch automatic transmission thing--and not likely to buy one myself.
  5. Speed Daemon

    Speed Daemon Disabled

    First of all, there are major differences between dual clutch automatic transmissions and dual clutch manual transmissions. The automatics, like all automatics use torque converters and hydraulic controls. The manual ones are like normal manuals, but with two clutches.

    The manual ones are easier to understand because a typical manual transmission has two gear shafts. Using two clutches allows each shaft to couple and decouple to/from the engine separately, which provides a number of benefits. Most of these are best realized when the transmission is under computer control. Because the typical arrangement has odd gears on one shaft and even gears on the other, being able to actuate the shafts independently allows for easier synchronization of gears and much faster shifting than is humanly possible. Since having two sticks to stir would be self-defeating, dual clutch manual transmissions rely on computers, electrical actuators and flappy-paddle shifters.

    Because of all of the automation, it's not much of a stretch to get the computer to take over all of the shifting decisions, making a semi-automatic transmission. Because they can, that's why. :D Seriously, every true manual transmission driver has wished for an "instant automatic" at one time or another.

    Dual clutch transmissions are best known for being in racing and exotic cars, but have been used in economy cars (like dibblebill's Diesel VW), heavy trucks and even trains. The bottom line is that they're just more efficient.
  6. Speed Daemon

    Speed Daemon Disabled

    Nope, no clutch pedals, no shift levers. Two clutches means twice as many controls if try to you do it all the traditional way. I'm sure someone has actually built a two-shifter and two-clutch pedal transmission just for the fun of it. But since most of us don't have the extra limbs, computers are needed to make it practical.
  7. dibblebill

    dibblebill Well-Known Member

    I'll take a picture tomorrow or this weekend for you. I don't have flappy paddles (though they can be fun. Test drove a few cars with them). My 'Manumatic' mode consists of pushing the gearshift forward or backwards. I've driven a Focus Manual and a Mustang Manual, and that's it. Old roommate never let me near his Miata (or the subsequent Corvette, or his final Golf R he settled on... All manual)
  8. unnamedny

    unnamedny Well-Known Member

    Dual clutch transmission usually comes with pedal shifters. It's faster gear changing than automatic or manual, it has almost no delay in shifting.
  9. Speed Daemon

    Speed Daemon Disabled

    I learned to drive a manual shifter on the farm, and didn't immediately come to appreciate how fun they are in high performance applications until much later on. I did prefer their simplicity though. I can replace a manual clutch easily. Not so easy for an auto trans clutch band! With my Mustangs I became addicted to "point and shoot" driving, where I squeeze the throttle in direct proportion to how far down the road I want the car to be at any given time. No lag, no wild kick-downs, no problem. So much more feedback from the road too!

    My truck has a computer controlled 6-speed automatic transmission that, even though it has twice the number of gears as its ancestors, can never find the right one at any given time. I got pulled over for the first time in a very long time while I was being buzzed by a bunch of ricers. One was tailgating me, and as it disappeared from view, hidden behind the tailgate, I ever so gently added throttle. On a manual, I would have seen instant and linear results. In this slug I got nothing until, right as I was passing a parked police cruiser, it downshifted into a very low gear and gave me the scare of my life! Why the cop failed to see four brightly colored buzz-bombs driving recklessly and singled me out is still a mystery. :rolleyes: At least it was only a warning that I got.
  10. dibblebill

    dibblebill Well-Known Member

    I actually don't have any lag issues from my Jetta. THe kickdowns are very predictable and timely, and its almost always in the right gear. Unlike my old automatic Oldsmobile and Plymouth Voyager...
  11. Speed Daemon

    Speed Daemon Disabled

    You have a copy of the Porsche Tiptronic
  12. Speed Daemon

    Speed Daemon Disabled

    Pedal shifters? That's a new one! I gotta see a video of that in action!
  13. Speed Daemon

    Speed Daemon Disabled

    Be thankful that you have an American BorgWarner, not my German ZF transmission! I'm no fan of automatic transmissions from the American "big three", but this ZF is definitely worse. Custom computer programming has helped a little, but I'd prefer a Richmond or Tremec 6-speed manual in its place.
  14. MoodyBlues

    MoodyBlues - Crazy peacock person -

    Okay, now I'm thoroughly confused. :confused: I thought dual clutch was strictly an automatic thing.

    See above. :confused:

    That all makes perfectly good sense...but I'm still confused. I still thought/think that dual clutch is unique to automatic transmissions.

    Ugh! Not for me. *I* like making my own decisions. Therefore, as much as I would love to drive a race car, I would HATE having the sequential manual transmission it may very well have nowadays. Trust me, if I need to go from 5th to 2nd, there's a damn good reason for it! (Like traffic suddenly stopping on a freeway for an accident.) Or from 1st to 3rd. (Like coasting down a mountain.) I don't want any computer doing the thinking for me. :mad:

    No. Yes. No. Unequivocally no. Maybe. Yes. Okay!! Once every 10 years or so I'm in a situation where my clutch foot hurts like hell (creeping up to Griffith Observatory, in bumper to bumper traffic, to see the Space Shuttle Endeavour fly over the Hollywood sign comes to mind), and I find myself thinking--momentarily--gee, an automatic sure would be nice!

    I thought these were different--I know they use paddles, but I thought they were sequential manual transmissions, meaning that you can only up- or downshift one gear at a time, in order, but it's still a manual transmission.
  15. Speed Daemon

    Speed Daemon Disabled

    Oh no, not at all! Although automatic transmissions have varying numbers of internal clutch bands and packs to shift gears, that's a completely different thing from the clutch (or clutches) in a manual transmission.

    With the manual transmission, the clutch connects or removes the flywheel from the input shaft, so the motor doesn't stall when you're stopped and to make it easier when you shuffle the gears around. This clutch is traditionally controlled by your left foot.

    In an automatic transmission, the clutches apply pressure to one or more planetary gear sets, causing them to rotate differently and change the gear ratio. These clutches are traditionally controlled by a valve body (essentially an analog computer) which is in turn controlled by the gear selector lever, or in the case of old Chrysler cars, buttons.

    Oh, joy.

    See above. ;) The torque converter in an automatic goes where the clutch would be on a manual transmission. Like the manual clutch, it keeps the motor from stalling when you're stopped, and aids in shifting gears. But it's not a clutch.

    Now the really confusing part: Later model automatic transmissions have clutches where the clutch would be on a manual transmission, and it looks and even works like the clutch on a manual transmission. But it's there for a completely different reason. So your average automatic transmission is full of all sorts of clutches of varying shapes, sizes and functions!

    No. At least not the kind of clutch that is traditionally operated by your left foot. That kind of clutch is native to the manual transmission. They can take an automatic transmission complete with all those internal clutches that make shifts feel like chewing rubber bands, and graft a double clutch onto the front of it. But it's still like chewing rubber bands! No thanks!

    Like I said above, automatic transmissions, by design use all sorts of clutches to do pretty much everything. The single clutch in a traditional manual transmission has only one function: to couple/decouple the engine's crankshaft (via the flywheel) to/from the transmission's input shaft. Poetry in motion. :driver:

    As we already learned, manual transmissions use two or more parallel shafts to hold its gears, and the gears move up and down the shafts to enable different pairs of gears to mesh, thus giving you different gear ratios. No internal clutch packs or bands, no planetary gears.

    Here's the tricky part. You have two shafts with gears on them, and one is the input shaft. Why is that one shaft the input shaft? Why not the other shaft? The answer is that you can have more than one input shaft if you want to. That is, in a nutshell the whole basis for double clutch transmissions: You can apply engine power to either of the two shafts if you want to. You can apply power to more than two shafts, in fact. It's entirely possible that one day we'll see a 6 shaft, 6 clutch transmission with God-knows-how-many gear ratios on it. :eek:

    The next logical question is "why?" I covered that in a previous post, but in essence it's for faster-than-human shifting and better efficiency.

    The good news is that you can tell the computer to get out of your way. And while flappy paddles may not lend themselves to the kind of gear-stirring that we both know and love, the transmission itself is not a sequential gearbox. If you slow the computer down so it waits until you have the chance to do at least a double-tap [sic], you can use multiple "taps" on the flappy paddles to go straight to the gear that you want. Inside the transmission it works exactly like it would with a stick shift, except that the computer is juggling what would be two sticks and the two clutches. But the important thing to know is that if you go from 5 to 2, you actually go from 5 to 2, with no stops in between. In fact, because of the second clutch you can go from 5 to 2 a lot faster than you ever could with a single clutch and a single stick shifter.

    Granted, it's not as visceral as having your hand on the shifter, and feeling things like the slight eccentricity in the pilot bearing, the thrust from the rear end and other tactile feedback that you'll never get with flappy paddles. That's why quite a few people absolutely hate flappy paddles, and the major supercar makers offer a standard shifter on their cars.

    Told you so! :laugh: But you want it just for the moment, right? You're not going to give up that solid connection between the flywheel and the pinion shaft that only a manual transmission provides. No "slushbox" torque converter! And when you want it gone, it's gone. Poof! :hello2: Can I get an Amen?!?!?

    Well, that's the beauty of the computer-shifted manual transmission. It gives you that direct connection, and the same random access gear changes that a manual transmission gives you. But it can do automatic once in 10 years, and go away the instant you want it gone.

    The bad news is that you have to find something else to do with your left foot and shifting hand. :(

    It's all about the interface. Flappy paddles are biased towards sequential shifting. A bad interface. But as long as the transmission itself has the same random access capabilities as every other manual transmission, love will find a way. :car:
    MoodyBlues likes this.
  16. MoodyBlues

    MoodyBlues - Crazy peacock person -

    Thanks for the excellent reply, Speed. :)

    --and I'm not willing to part with!

    After living in Dallas for so long, and then returning home to Southern California, I've rediscovered the joy of mountain driving. I LOVE, love, love the control I have in my 5-speed stick, 4WD vehicle going up and down winding, often steep, mountain roads.

    Shifting is so natural for me, so much a reflexive action, that it's hard for me to think in terms of something being SO MUCH faster that it would be noticeable--or desirable. You know what I mean? Like if it takes me 15 milliseconds to shift from 5th to 2nd, but a computerized setup could do it in 10 milliseconds...who cares?!


    On the very rare occasions when I've driven an automatic since switching to manuals, my poor left foot has felt so lost. I had to consciously, continually remind myself to keep my foot on the floor. And my right hand constantly found itself reaching for the gear shift...
  17. Speed Daemon

    Speed Daemon Disabled

    You're quite welcome! :)

    Me neither. Computers are fine for making the suck, squish, bang and blow part of driving more clean and efficient, and for helping with panic stops. But that's far enough for my tastes.

    When I returned to my homeland of Northern California, I made the mistake of allowing myself to get upgraded to a SUV. Big mistake! When I was driving to a party in Mountain View, I was on roads that were ideal for a little car like my Mustang. After that I rented Mustangs, but there's no place that rents manual transmission cars, so...

    Here in Wisconsin the rolling hills are great fun with a 5-speed!

    Who cares? WHO CARES?!?!? I'll you who cares! Wealthy old men, that's who cares! That's riiiiiight! Shriveled-up old farts who can barely see the road, who take their half-million dollar cars out exactly one day a year, and spend the other 364.25 days bragging about how they can shift faster than Aryton Senna ever could ('cuz he died in 1994 mainly). Them and race car drivers, and other wannabes. That's about it. :boring:

    To be fair, it's more like 500ms+ for the average driver. You can cut that in half if you're a young and fit race driver with lightning reflexes and a hand-made gearbox and shifter that costs as much as a nice house. So the 8ms that the latest dual clutch gearboxes can do is a significant improvement when you're drag racing...or road racing...or racing racing... If you're not racing, then not so much.

    I remember a fellow gearhead getting tickled when I told a driving story because my posture and hands and feet unconsciously did what I was talking about. Like a dog dreaming.

    Since I have to switch between my Mustang with its summer tires and my truck with its 4WD and pickup bed frequently, I find myself trying to press a clutch pedal that isn't there, and as I pull up to stop lights I'll try to move the automatic shifter side to side like I do with my manual to make sure it's in neutral before I release the clutch. It's embarrassing. Not really.
  18. dibblebill

    dibblebill Well-Known Member

    I appreciate the explanations. Didn't know that about the transmission. Its still expensive to get swapped. Just glad I didn't get that German one, then. I wouldn't trade the DSG in my Jetta for a manual any day of the week, but a sports car, I'd have a manual for sure.
  19. jhawkkw

    jhawkkw Chinchillin' Moderator

    The last time I drove an automatic, my left foot got confused while hunting for the clutch, and it found the break :eek:. Good thing I was on a deserted country road.
  20. dibblebill

    dibblebill Well-Known Member

    Alright, here's my gearshift lever.

    Attached Files:

    MoodyBlues likes this.
  21. MoodyBlues

    MoodyBlues - Crazy peacock person -

    dibblebill, the + and - next to D, which I assume means up/down a gear, how do you activate those? They kind of look like pushable buttons, but kind of not. :confused:
  22. Speed Daemon

    Speed Daemon Disabled

    Just to be clear, I'm not saying that German stuff is crap or anything like that. I was highlighting the irony of the situation, because German engineering tends to be top notch as a rule. In this case BorgWarner (two good German-American names, BTW) seems to have the better product. Although my transmission is a ZF design, BorgWarner designed the transfer case in my truck, which is so cool that it was a deciding factor for me buying it.

    You have a very nice package going on, for what it's designed to do. The turbo-Diesel and the extra-efficient transmission must give you excellent mileage without having to be obsessive about your driving style. When I'm on the road in my 4x4 and see my dismal MPG numbers, I wish I had something like that!
  23. Speed Daemon

    Speed Daemon Disabled

    If it works like the Tiptronic, you just move the lever forward to go up a gear, and back to go down a gear. It's a lever action, just like the B&M shifter I showed earlier. Unlike the B&M, which uses a ratchet mechanism to move an old-school shifter cable, dibblebill's shifter has electrical contacts at the other end of the lever that make it an input device for the drivetrain computer that controls the double-clutch transmission.

    Dibblebil, when you're in manual mode, if you give it two or more bumps, will it skip a gear or two? I don't see any reason why your transmission itself can't go directly from one gear to any other gear without any intermediate stops. The question is whether or not the shifter (and computer) supports it too.
  24. dibblebill

    dibblebill Well-Known Member

    I bump the lever to the right to activate it. It will let me skip gears so long as it doesn't think I'll damage the transmission or engine.
    Speed Daemon likes this.
  25. Speed Daemon

    Speed Daemon Disabled

    That's a real handy thing! I've inadvertently downshifted into first gear at speed, thinking it was third, confidently let out the clutch and heard that horrible sound of an engine over-revving and breaking valvetrain components before, and never want to go through that again. :eek: That's another nice thing about computer controls: they will stop you from doing something that you'd never want to do. Doubleplusgood!

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