RedLS6

Did you read the last sentence I posted? Here it is again;

One interesting thing about this transaxle is "if" and "how" it'll incorporate some form of the current E-diff capability. I wouldn't be surprised if GM partnered with Tremec or Linamar or another, given the cost to develop a new transmission.

http://www.linamar.com/technology



~

JoesC5

The AMG GT R has a DCT transaxle and it has a electronically controlled limited slip differential.

"Electronically controlled: rear-axle limited-slip differential

As standard, the AMG GT R is equipped with an electronically controlled limited-slip differential on the rear axle, which is integrated into the compact transmission housing. Its sensitive and rapid control elevates physical handling limits to a new level. It not only further improves the grip of the driven wheels, but also increases cornering speeds at the limit. The system operates with a variable locking effect in acceleration and overrun mode, and is perfectly tuned to various handling conditions and road friction coefficients."

No new frontiers have to be discovered to incorporate an eLSD onto a DCT transaxle.

As an owner of C6Z06, I sure hope that Linamar isn't involved, since they did such a bang up job machining the LS7's heads to perfection. Spare me.

RedLS6

Yup I know that, the interesting part is in guessing if and how they might improve it, instead of just using existing technology. There are more advanced diffs out there than either the AMG or the C7 diff, as well as simpler ones that make some tradeoffs and function almost as well. Always fun arguing with you, Joe.

Corvette#2

If this is true, it could really add to the long term desirability/collectibility of the ZR1. I know the 6 speed F430s are worth a lot more than an F430s with an F1 paddle shift transmission.

SSsedanM6

Change that caption to "Torque Converter Automatic", and everyone should agree with you.

I think it's absolutely ridiculous that you prefer a clutch pedal to DCT/PDk.
But, I still think you should have an option for a clutch pedal in a sports cars.
Even thought DCT makes the clutch pedal irrelevant to everyone but the nostalgic.

SSsedanM6

And that's why all of GM's excuses for not offering a DCT at the launch of the C7 were transparent lies, that insulted buyers, especially the Corvette Faithful.
The C8 better make up for previous shortcomings.

SSsedanM6

A DCT with more than 7 gears....

RedLS6

....represents new and improved technology targeting planetary ratio performance, which is what we want.

jimmyb

This how YOU get yourself in trouble....
I prefer a manual to an automatic (DCT or TC) in my sports cars. And it is NOT ridiculous, it is a PREFERENCE.

No one died and made you king, try to keep that in mind. Your money, your choice. My money, my choice.

jimmyb

Exactly. This comes up about once a year, with folks calling DCT's "manual". If it will shift itself, it's an automatic. Don't care if it defaults to paddles on start up....if there's a D in the pattern, it's automatic.

jimmyb

I am as well and I fear our time with 3 pedals is coming to a close. I will be shocked if the ME offers a manual (but I never thought they would make a C7 GS so...)

SSsedanM6

What part of "I think the rev-matching stick should remain an option" didn't you comprehend?

Your post is ironic because it's only people like you that are clueless about DCT that want to deny others the options they want,
not me.


I'll add this to the list of things you don't comprehend.
DCT actually IS a manual transmission.
There's no way for a human to operate both clutches while simultaneously working the gas and brake pedals.
So, the clutches must be activated by the computer.
Calling a DCT an automatic just makes you sound absolutely clueless.

Trouble? I'll be just fine, thanks.
King? OK, pal.

jimmyb

OK sport. EVERY car magazine that tests a car with a DCT calls it an "automatic". Feel free to check me.
Will a DCT shift itself?
What is YOUR definition of "automatic"?
You really are a piece of work. Not only do you NOT accept that anyone can have a different view, you also have to be nasty about it. Oh well, you'll be banned again soon since you just can't seem to figure out how to have a normal conversation without trying to be superior.

PS. I responded to you in the first place because of your "I think it's absolutely ridiculous that you...."comment.
And, I assure you, I have driven MANY DCT/PDK equipped cars. I like them, I prefer a manual. Is that OK with you?

PurpleLion

DCTs have historically been referred to as manual transmissions because they function the same as a manual transmission with out the normal parasitic losses of an automatic transmission. After a DCT completes a shift, the drive-train is locked just like it is with a manual transmission (with a manually operated clutch). DCTs do have an "automatic" operating mode and this mode can be the default, requiring the driver to select manual mode if he/she wants it. Recently DCTs are being called automatics - probably due to marketing concerns. So DCT equals direct lockup - very efficient vs an automatic - planetary with torque converter and with the traditional losses of an automatic.

This is now being complicated due to the fact that some DCTs are incorporating torque converters for startup / low speed operation. In this scenario, the torque converter drops out at some point and the transmission reverts to full locked operation. The torque converter in this setup is what will keep your wife happy! Also, if she asks you whether it is a manual or an automatic, you can tell her that it is an automatic! Especially since it functions just like a normal automatic!

When driving at a track, an accomplished driver would always use a DCT in manual mode so that he/she can downshift while braking at a corner entry, thereby using engine braking and getting the engine "on the boil" to use the throttle to help steer the car through the apex and out of the corner. When driving any transmission in automatic mode, you lose the benefit of having immediate control of the engine. In my view, when you use the paddle of an automatic (planetary) transmission, it is like you are asking the transmission to "please change gears", when this happens is under the control of the transmission. With a DCT transmission, the change is immediate and much faster than you would be able to change gears if the DCT had a manually operated clutch.

I am not an expert on automatic (planetary) transmission design, but I think that these transmissions shift using hydraulic pressure which might be why there is a lag in the completion of a shift whereas with a DCT gears are moved and clutches are engaged and disengaged using immediate acting servos. Hopefully someone can explain this better and also give us some idea of how planetary transmissions are getting faster (higher operating pressures?).

jimmyb

No doubt, DCT construction is that of a manual transmission, with computer controlled clutches (automatic that would be). My only point is that a DCT will function automatically (shift itself) which, in my mind, makes it an "automatic". It is not about the construction of the transmission, only how it behaves. This is just my opinion.

FWIW, the July 2017 Car and Driver featured a piece comparing the GT3, 720S, and Ford GT. All 3 cars had DCT's (the GT3 also offers a 6 speed manual as a no cost option). Car and Driver referred to the transmissions in all three cars as "7 speed dual-clutch automatic with manual shifting mode". Again, FWIW.

Bill Dearborn

What has that picture got to do with a DCT? It is a slush box which is different than a DCT. Still don't understand why the shifter location bothers you. Over the years shifters for manual transmissions have been located on the floor and the steering column. My first car a 55 Chevy had a manual transmission with the shifter located on the steering column. We used to call it three on the tree. What is the difference between that and having a couple of paddles located on the steering wheel? They still change the gears just with a hell of a lot less movement of your arm.

I find this video shows how close the DCT is to a regular manual transmission.
One of the reasons why you can't use a shift lever to move the gears and your foot to operate the clutches is because humans probably couldn't synchronize movement of the shift forks with which clutch is being engaged. You have one foot and would have to have two clutch pedals to make the unit completely manual. Might be a little bit of a challenge to operate quickly.

Bill

Suns_PSD

I know that every automatic transmission owner (DCT, WHATEVER) makes a valid point when they correctly state that manuals transmissions are often a bit slower at the racetrack, and if ultimate performance is the goal, then automatic is the choice.

But I'm not racing for money or trophies I just like to do some laps and have fun, and a manual transmission does that better for me.

I might also add out of all the supercars I've seen on the track many of them with DCT automatic transmissions, they've all been roadblocks for me. It's still mostly comes down to the driver.

JoesC5

Is a DCT with a torque convertor as used by Acura(and GM also has a patent on one) an automatic or a manual transmission?

jimmyb

^^^^^
Good question Joe!!!

thebishman

It would be more correct to describe a DCT type of transmission as a ‘manual transmission with automated control of the clutch action’. But this of course would be extremely confusing to the general public, hence over time these types of transmissions are referred to as ‘automatics’, even though they are far removed from a true TC transmission.

Personally I hope the C8 has both a true ‘Manual’ transmission with a third pedal for those that want/enjoy them, and a DCT transmission so that it can be as competitive with the competition as possible and offer the choice to those of us who now prefer a DCT far more than a manual.

Bish