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DCT and Turbo combo < C7 stick

 
Old 01-19-2019, 03:37 PM
  #41  
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Originally Posted by PurpleLion View Post
Especially when downshifting. A paddle shifted DCT is identical to a manually shifted transmission, but without the clutch.
Really??? That reminds me of a label that once appeared on Nalleys cans of Chili. The label read: "Chili con Carne without meat." Your contention makes about as much sense.

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Old 01-19-2019, 05:02 PM
  #42  
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Originally Posted by mschuyler View Post
Really??? That reminds me of a label that once appeared on Nalleys cans of Chili. The label read: "Chili con Carne without meat." Your contention makes about as much sense.
Only difference is that the clutch is operated automatically by the systems hydraulics. Still has a clutch, you just don't have to push the pedal since the clutch is operated automatically by virtue of your using the paddle. Not really that big of a difference!
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Old 01-20-2019, 01:59 AM
  #43  
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Originally Posted by PurpleLion View Post
Only difference is that the clutch is operated automatically by the systems hydraulics. Still has a clutch, you just don't have to push the pedal since the clutch is operated automatically by virtue of your using the paddle. Not really that big of a difference!
Tell that to my left foot.
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Old 01-20-2019, 11:50 AM
  #44  
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Originally Posted by Michael A View Post
Tell that to my left foot.
Hey Left foot, learn to use the brake, braking technique is where fast drivers get really fast.

Last edited by Lacquer; 01-20-2019 at 11:52 AM.
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Old 01-20-2019, 11:55 AM
  #45  
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Originally Posted by PurpleLion View Post
Only difference is that the clutch is operated automatically by the systems hydraulics. Still has a clutch, you just don't have to push the pedal since the clutch is operated automatically by virtue of your using the paddle. Not really that big of a difference!
Not to be presumptuous, but the above statement could only be written by someone who has never operated a clutch. There’s no way to modulate the clutch pressure on a DCT. So really, a HUGE bit of difference...
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Old 01-20-2019, 12:01 PM
  #46  
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Originally Posted by kozmic View Post

Not to be presumptuous, but the above statement could only be written by someone who has never operated a clutch. There’s no way to modulate the clutch pressure on a DCT. So really, a HUGE bit of difference...
Actually there is. A good DCT has several personalities available at a moments notice that will allow you to have super soft engagement to slam you in the seat shifts.
The one thing that many are missing is you will never have a money shift with a DCT, even in full manual mode.

Last edited by Lacquer; 01-20-2019 at 12:06 PM.
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Old 01-20-2019, 01:13 PM
  #47  
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For people not familair with DCT's, this might be instructive in terms of what DCT's can do. Many of the DCT's in use utilize clutch packs and shifting electronics and solenoids made by Borg-Warner. The solenoids move shifting forks identical to the forks that a stick shift moves in a manual transmission.

Here is a picture of the solenoids that move the shift forks back and forth to engage the gears. The shift forks are engaged by the square shaft linking the 4 pairs of solenoids. This is the module that allows the computer to do what your arm does in a manual transmission. The solenoids move back and forth inside their bores under electronic activation commands issued by the driver via the paddles on the steering wheel or via the software under automatic operation.
[img]https://www.kageki-racing.com/photos/services/nissan-gt-r-r35-transmission/gtrbox-(2).jpg

Now here is a picture of the gears and shift forks in a DCT that are virtually identical to those in a manual transmission. It's a little hard to see but there are 4 points with 2 square pins sticking up which is where the square shafts of the solenoids engage. 3 of those points are for the main forward gears ( gears 1 through 6) and machined into the gray colored forks and the 4th point is a dark oil covered "fork" for activation of the reverse gear via the round shaft.

The solenoids engage the shift forks at the point where the pins stick up. So the DCT is entirely like a manual transmission with helical gear sets, dogs, etc. and has nothing in common with an automatic transmission using valve bodies and torque converters.

Here is a clutch pack from the DCT along with all of the gears and shafts. Anyone familiar with the parts in a manual transmission will recognize the DCT's parts and see they are very similar.



In terms of clutch operation, for example the DCT in a Nissan GT-R has 4 adjustments that change the feel and performance of the shifts, 2 for each clutch pack. There is one clutch pack for odd numbered gears, 1-3-5 and one clutch pack for even numbered gears, 2-4-6. The adjustments are called "clutch capacity" and "clutch touch point". Each adjustment has a range form 0 (base setting) to +/-7. You can set all of the adjustments to negative values, and this allows clutch slip and softer engagement as you might use on the street, or all the adjustments to positive values which makes for harder, faster shifting. Using the softer negative settings for street use is ill-advised for track use as they allow for clutch slip which causes excessive heating. These are typically dealer adjustments, or via the use of a plug-in ECU tuner. One can have the computer learn the clutches at anytime to adjust for wear for the base 0 settings, and then program the capacities and touch points as desired, as many times as one likes, including just before and just after a track day. One thing that gets programmed via the settings is creep, where the car moves forward in gears with no throttle just like in a car with a slush box.

There is nothing to fear about a DCT, and many things to like, and that is one reason why virtually ever high end sports car on the planet currently made uses them. And like Tadge said, the manual's days are numbered. It was no surprise the new 700+ HP Mustang only comes with a DCT built by Tremec.
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Old 01-20-2019, 01:18 PM
  #48  
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Originally Posted by PurpleLion View Post
Only difference is that the clutch is operated automatically by the systems hydraulics. Still has a clutch, you just don't have to push the pedal since the clutch is operated automatically by virtue of your using the paddle. Not really that big of a difference!

So "using a paddle" is like 'shifting a gear lever"? I feel like I'm reading George Orwell's "1984" where it proclaims "War is peace." I don't know whether to laugh or cry, but I do feel sorry for you.

Last edited by mschuyler; 01-20-2019 at 01:21 PM.
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Old 01-20-2019, 01:40 PM
  #49  
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Originally Posted by mschuyler View Post

So "using a paddle" is like 'shifting a gear lever"? I feel like I'm reading George Orwell's "1984" where it proclaims "War is peace." I don't know whether to laugh or cry, but I do feel sorry for you.
Yes in that it performs the same action.

Do you use rev matching, do you double clutch - heel and toe?

Again many motorcycle riders don't use the clutch because they know how to rev match! Can do the same in a car w/o DCT.

Some people seem to be making a major issue out of a relatively minor difference IMO.

The important knowledge that one learns when driving a manual is when to shift up, when to shift down and what gear should be used. All of these decisions must be made when using a DCT if you have it in manual mode. If you have it in automatic mode on a track, you are giving up a lot of control.
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Old 01-20-2019, 01:52 PM
  #50  
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Originally Posted by Lacquer View Post
Actually there is. A good DCT has several personalities available at a moments notice that will allow you to have super soft engagement to slam you in the seat shifts.
The one thing that many are missing is you will never have a money shift with a DCT, even in full manual mode.

oh man... no kidding. ... loved the egear so much... ive destroyed a manual trannys... with a 1-2-1 shift.. w slicks... its not fun. will take a good dct any day....
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Old 01-20-2019, 01:57 PM
  #51  
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Originally Posted by descartesfool View Post
For people not familair with DCT's, this might be instructive in terms of what DCT's can do. Many of the DCT's in use utilize clutch packs and shifting electronics and solenoids made by Borg-Warner. The solenoids move shifting forks identical to the forks that a stick shift moves in a manual transmission.

Here is a picture of the solenoids that move the shift forks back and forth to engage the gears. The shift forks are engaged by the square shaft linking the 4 pairs of solenoids. This is the module that allows the computer to do what your arm does in a manual transmission. The solenoids move back and forth inside their bores under electronic activation commands issued by the driver via the paddles on the steering wheel or via the software under automatic operation.
[img]https://www.kageki-racing.com/photos/services/nissan-gt-r-r35-transmission/gtrbox-(2).jpg

Now here is a picture of the gears and shift forks in a DCT that are virtually identical to those in a manual transmission. It's a little hard to see but there are 4 points with 2 square pins sticking up which is where the square shafts of the solenoids engage. 3 of those points are for the main forward gears ( gears 1 through 6) and machined into the gray colored forks and the 4th point is a dark oil covered "fork" for activation of the reverse gear via the round shaft.

The solenoids engage the shift forks at the point where the pins stick up. So the DCT is entirely like a manual transmission with helical gear sets, dogs, etc. and has nothing in common with an automatic transmission using valve bodies and torque converters.

Here is a clutch pack from the DCT along with all of the gears and shafts. Anyone familiar with the parts in a manual transmission will recognize the DCT's parts and see they are very similar.



In terms of clutch operation, for example the DCT in a Nissan GT-R has 4 adjustments that change the feel and performance of the shifts, 2 for each clutch pack. There is one clutch pack for odd numbered gears, 1-3-5 and one clutch pack for even numbered gears, 2-4-6. The adjustments are called "clutch capacity" and "clutch touch point". Each adjustment has a range form 0 (base setting) to +/-7. You can set all of the adjustments to negative values, and this allows clutch slip and softer engagement as you might use on the street, or all the adjustments to positive values which makes for harder, faster shifting. Using the softer negative settings for street use is ill-advised for track use as they allow for clutch slip which causes excessive heating. These are typically dealer adjustments, or via the use of a plug-in ECU tuner. One can have the computer learn the clutches at anytime to adjust for wear for the base 0 settings, and then program the capacities and touch points as desired, as many times as one likes, including just before and just after a track day. One thing that gets programmed via the settings is creep, where the car moves forward in gears with no throttle just like in a car with a slush box.

There is nothing to fear about a DCT, and many things to like, and that is one reason why virtually ever high end sports car on the planet currently made uses them. And like Tadge said, the manual's days are numbered. It was no surprise the new 700+ HP Mustang only comes with a DCT built by Tremec.


hell yeah brother...... done w a street car w a stick...the dct is a game changer on the street for the 1/4...
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Old 01-20-2019, 02:01 PM
  #52  
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hell.. if its not awd... the front sway bar may be coming off or quick links installed...for weekends...
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Old 01-20-2019, 02:34 PM
  #53  
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Originally Posted by PurpleLion View Post
Yes in that it performs the same action.

Some people seem to be making a major issue out of a relatively minor difference IMO.

The important knowledge that one learns when driving a manual is when to shift up, when to shift down and what gear should be used. All of these decisions must be made when using a DCT if you have it in manual mode. If you have it in automatic mode on a track, you are giving up a lot of control.
I feel like I'm in Bizzaro World, a place where you pretend an auto is a manual. Now I'm supposed to believe the difference between the two is "relatively minor." So a DCT is just like a manual except it doesn't have a clutch pedal and it doesn't have a gear shift lever. Other than that it is the same!

Okie Dokie! But like I said, "Chili con Carne without meat" makes as much sense. Or does no one get that either?
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Old 01-20-2019, 02:47 PM
  #54  
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Originally Posted by kozmic View Post

Not to be presumptuous, but the above statement could only be written by someone who has never operated a clutch. There’s no way to modulate the clutch pressure on a DCT. So really, a HUGE bit of difference...
The clutch pack in the eLSD is hydraulically controlled. How do they modulate the amount of slippage there?

Last edited by JoesC5; 01-20-2019 at 02:54 PM.
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Old 01-20-2019, 03:10 PM
  #55  
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Siento tu dolor bro, pero disputas destruyendo una tranny en 1-2-1, sin carne es mejor q sin tranny...jjajajaa
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Old 01-20-2019, 04:04 PM
  #56  
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Originally Posted by mschuyler View Post
I feel like I'm in Bizzaro World, a place where you pretend an auto is a manual. Now I'm supposed to believe the difference between the two is "relatively minor." So a DCT is just like a manual except it doesn't have a clutch pedal and it doesn't have a gear shift lever. Other than that it is the same!

Okie Dokie! But like I said, "Chili con Carne without meat" makes as much sense. Or does no one get that either?
You are really missing the point. And numbingly repetitive to boot!

The guy you are "arguing" with is not saying what you say he is saying.

descartesfool's excellent post lays it out clearly. The DCT is internally almost identical to the typical stick many of us have operated for many years (in my case 40 WITHOUT owning any slushboxes). It is truly a hybrid. And so, to your left foot it won't feel ANYTHING like a clutch operated manual, but to your butt it will feel the same but much quicker. As you use it, it will perform better than either, though obviously you will need to find something to do with your left foot.

That will appeal to many manual lovers (I personally believe more than half), and probably prettty much all slushbox lovers. I can only speak for myself -- I would NEVER have a slushbox (at least like any one I have ever been forced to drive over the last 4 decades) -- but, if I am fortunate enough to afford a C8 before I am too old to enjoy it, I would be excited about the DCT.

I mean, I see your point, and the Nally's chili can example is really funny, but why can't you understand that we all get, and have gotten every time this stupid debate has cropped up, that the DCT has an automatically operated clutch (well, for efficiency, two of them) and therefore is different from today's M7 -- but those differences are far less important to some folks than others.
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Old 01-20-2019, 04:12 PM
  #57  
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Originally Posted by kozmic View Post
Not to be presumptuous, but the above statement could only be written by someone who has never operated a clutch. There’s no way to modulate the clutch pressure on a DCT. So really, a HUGE bit of difference...
Just my opinion. Some people are reacting to this as if they just learned how to drive a manual so I will be getting off of the subject.

For the record, I have been driving manual shift cars and motorcycles for over 58 years, both on the road and on the track. So, yes, I know how to operate a clutch!
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Old 01-20-2019, 04:33 PM
  #58  
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Originally Posted by PurpleLion View Post
Just my opinion. Some people are reacting to this as if they just learned how to drive a manual so I will be getting off of the subject.

For the record, I have been driving manual shift cars and motorcycles for over 58 years, both on the road and on the track. So, yes, I know how to operate a clutch!
okay, great... I have been using a clutch all my life too... cars/bikes/others... if you have as well, then I’m even more surprised by your previous comment... your opinion that a DCT could be used in similar ways as a manual, for your personal purposes, does not in any way mean there is “not really a big difference”. I actually like a good DCT for certain reasons, but “a third pedal and shifter” it will never be...

agree with the above... starting to feel like bizzaro-world around here...
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Old 01-20-2019, 04:39 PM
  #59  
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Originally Posted by kozmic View Post

Not to be presumptuous, but the above statement could only be written by someone who has never operated a clutch. There’s no way to modulate the clutch pressure on a DCT. So really, a HUGE bit of difference...
Originally Posted by JoesC5 View Post
The clutch pack in the eLSD is hydraulically controlled. How do they modulate the amount of slippage there?
Joe, apologies if it wasn’t complete obvious... my comment was about driver/operator interaction/modulation of the clutch.

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Old 01-20-2019, 04:53 PM
  #60  
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Most people who swear by sticks like virtually all my track buddies have never driven a car with a DCT on track, so they don't really know the benefits or drawbacks (can't think of any). But a few of them who have ridden with me on track said, "I guess all that shifting stuff is for the birds". One of those guys is the one who just ordered a P car with a PDK for the track. They are often most amazed by how the transmission can up-shift mid-corner so seamlessly it does not upset the car. That's something I could never do on track with a manual. Just one of the factors that makes a DCT tranny faster on track.

Here is another picture, a cut-way of an AWD DCT showing the input shaft/flange inline with the dual clutch-pack at the front and then the gear-sets behind. The two clutch packs are located inline one behind the other, as shown in the cut-away. Shift forks are under the gear-sets in this picture so you can't see them. You can clearly see the gold colored synchro-rings just as found in any manual transmission. This is a rear-mounted trans-axle like a C7 with the diff in the back of the transmission. As it is AWD, there is a separate output shaft driven by a gear via a multi-plate clutch pack you can see in the cut-away.



Here is a video of a ZF transmission as used by Porsche with a similar but different design for a DCT.


Another benefit of a DCT people often do not realize is that you can never mis-shift it, as when you want to upshift to 4th gear from 3rd under full acceleration but mistakenly put it into 2nd gear, and over-rev and destroy your engine unless you are fast with the clutch. In a DCT, the computer just won't ever let you do that. Gives you the option of full manual shifting but eliminates engine destroying mis-shifts.
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