Shaka

There will be no DCTs in a Vette ever. Discuss.

Matt26

No.

travisnd

I actually agree. Modern converter autos can shift in < 0.1 seconds. I think we'll see a very trick 8-speed auto in the later C7s and hi-po C7s.

ByByBMW

I would like to believe they might appear. BUT, with the power band of the LT1, a DCT may not improve track times or driveability sufficiently to justify the added cost.

Shaka

I saw this section appear so I quickly started this thread to be the first. It will be so recorded in history books.

When the next low information member brings this subject up in the future, he can be directed to this thread.

There is a lot more to this question than one would think. With unlimited funds anything can be done. The real question is, is it the smart thing to do? The only application that is smart for a DCT, is in small front drive cars. GM global high volume FWD cars will have DCTs within a few years.
With a front engine rear drive car, the engineering obstacles begin to mount.

The project should immediately be discarded, because of the questionable concept of this so called advanced technology.
It is not advanced at all, because an Italian engineer installed such a device in a armored vehicle in the early 30s so that the vehicle would not get stuck in the sand or mud.
It has redundant features which adds mass and is totally dependent on modern electronics to function in a modern application although there were expensive English cars that that used them after the war.
It is in the 40s that the cyclic slushbox as we know it today became a more desirable direction for automatic transmissions rather than constant mesh gearboxes. Henry Ford copied French cyclic gear designs for his Model T and the rest is history.
Applications for auto transmission in high performance is not new. Jim hall began in the 60s but during the past decade or so and DCT technology, the high performance slushbox idea is being revisited with renewed industry. The DCT in high performance cars will die because of a couple of major reasons.

We will soon get reports of the A6 in C7s. This is a modified current GM gearbox and not what is already in production elsewhere. This 'ancient' A6 will give you some insight as to the direction of high performance auto transmissions.

Without getting into the shortcomings of the DCT, especially coupled to very high torque engines, which hopefully will be discussed at length as this thread unfolds, lets examine it from GM's point of view.

Are any of you familiar with GM's corporate culture? Does anybody know the major difference between a Rolls Royce or Packard Merlin engines and the Daimler Benz engines as opposed to the General Motors Alyson V12 engines that were used in aircraft of the WWII?
Do you know why the Alyson engine was far far superior? Remember, examine it from a GM cultural point of view.
Where did the technology come from to place the C5 gearbox at the rear. How was it done on a very low budget?
Do you know what a trans axle is? Why doesn't a Corvette have one and won't ever have one? Think GM.

Some facts/questions to consider in this DCT/Vette application. Will GM be able to use this transmission in other model lines? Will a low volume GM car receive a dedicated gearbox/ transaxle??
Has GM already invested in not only superior alternatives, but cost effective multi mark crossover applications?
Lastly, will GM consider only one Corvette gearbox or two or even 3???
Also consider, mass reduction in modern cars is a universal objective.
My heart belongs to the sequential gearbox and automatic versions have already been seen in F1. There is absolutely no other way to go. LFA, anybody??
This is ultru light and strong and a torque converter or a dry clutch can be used with it.
The next generation of slushboxes will also be light and strong. A Corvette DCT, would be the heaviest and most expensive one ever made.

Please, only intelligent responses and remember,
Think GM stock holders.

truth.b

ok.. now seriously. I agree that a DCT won't help a Vette as much as a car with a narrow powered band (Porsche, Ferrari, etc..). I feel a 7-speed similar to the 8-speed ZF trans would be perfect. flame suit on

VIN666

I think GM knows that one of the reason their products sell like they do, is their aftermarket support. So I would hope they don´t go to a trans that´s borderline capable of supporting the stock power, let alone mods.

Rkreigh

wrong. the aftermarket is already stepping up and has them available so they will indeed be adapted by those with deep enough pockets.

the factory will just likely go "advanced" autos as they do a decent job, are cheaper and lighter, and way less complicated.

if you want a DCT, just pull out your wallet.

if you want the factory to put one in, don't hold your breath. it won't be anytime soon, if indeed ever.

Shaka

The after market has a DCT for a Vette?

VIN666

Never heard of that either...
And even if they do, that doesn't mean that it's a feasible solution for a mass produced car.
Hell, 632 CI pump gas engines that make 800/800 are available in the aftermarket too. Ever seen one in a production car?

BanditSRT

I hope so. The sound they make between shifts is great! I love the DCT in my GTI.

Shaka

I said only intelligent responses on this thread. OK?

JoesC5

The Porsche 911 Carrera 4s has both a 7 speed manual and a 7 speed PDK transmission available.

Curb weight with the manual is 3186 pounds and the curb weight of the7 speed PDK is 3230 Pounds, An increase of 46 pounds over the 7 speed manual.

A 6L80 Corvette transmission weighs ~122-125 pounds more than the TR6060 transmission.

Looks to me that a PDK(DCT) transmission in a Corvette would weigh less than an automatic transmission, shift as fast, if not faster, and the car would weigh less.

GM has said that the auto transmission was not capable of handling engine RPM's over 6,500, not high lateral g's on the track. It would seem to me that both of those restrictions would be a hindrance in designing high performance sports car.

The Porsche 911 Turbo S has 560 HP at 6,500-6,750 RPM with 516 lb-ft of torque and 553 lb-ft of torque with Overboost. So holding up to horsepower levels above the current C7's 460 is not a problem.

The Mercedes SLS AMG Black has 621 horsepower, revs to 8,000 RPM with 468 lb-ft of torque. I really doubt if a GM automatic transmission will stand up to that. Oh, and the SLS AMG Black has a 7 speed DCT.

VIN666

And neither of those vehicles are transverse layouts.
I don't think that there currently is a DCT that would just bolt right in.

Shaka

I'm not going to kick every dog that barks around here.
I can poke big holes in each of your points or so called 'facts'.

My standard response: Get a pencil and draw the layout of the C7 DCT from crankshaft to axle. Include all shafts including differential and clutches.
Did your post pass thru the intelligent filter?

VIN666

Hahahaha.
You mean. You mean bro.

b4i4getit

Whats the point of this thread ? There will be something better than the A6 coming soon. Who cares what it is called.

Shaka

As long as it is not called a DCT it will be fine with me.
There are a zillian threads praising the DCT and many posters want to see it on a Vette. This thread gives gives them the opportunity to present their case.
I personally can't see how it can be done within design objective parameters that Tadge stated.
If there is anybody that can show me how it can be done, I will be the first to congratulate them.

I see it as a big heavy expensive POS especially at the back of a Vette.
There are many factors to consider.

So if there is someone who advocates a DCT in a Vette who enters this thread and who can't present a reasonable feasibility study, I will attack them viciously.

JoesC5

I don't have to take a pencil and draw little lines like you, I just look past the end of my nose, unlike you.

What do you see in this photo(you can print it out and get out your crayons if that's what it takes)?

Shaka

Brother! What does a SLS cost? What does it weigh? How fast is it around the RIng? Do you think GM will build an 8000 rpm production engine? How high do you think the C7Rs engine will rev.?

Do you honestly think GM is going to build a transaxle like this?

What does this arrangement do to the CG, both longitudinally and vertically? Where do you put the golf clubs? Draw all the shafts with your crayons just for your own amusement. Check the angles of the side shafts. Plan and side view.


Or like this Ferrari FF. I'd would not admit to anybody that I was on this FF drive train design team if I were. I'd be ashamed.


They are both crap solutions and engineering nightmares.

Now, if you were talking sequential, I'd be with you.
Note how compact this is. Note were the single clutch is. Note the position of the gearbox in front of the rear axle. This is a thing of beauty, simplicity, lightness and strength.


Do you know that you can purchase this type of gearbox for your C7 right now? Today? There are some sequentials in Corvette street cars already.
Do you know that the LT1 requires a big flywheel/clutch or a torque converter bolted directly to the end of the crankshaft and they can't be remote? Do you know it can't rev up or down too fast therefore the gearbox does not need to change that fast as a F458 does.

Lastly, for this post anyway, GM will have a very light and strong A8 that will fit into Cadillacs and Vettes pretty soon.
Corvette does not have a transaxle which requires a single casing. This is engineering cost saving geneous which is the mark of GM.
I would like the M7, the A7 and for the hyper Vette, the sequential.
Or, just the sequential with a dry clutch or a torque converter. QED.