How much better is the C8 Tranny over the C7 Auto?

[Z_Rocks]

I just saw this video where John Hennessy is pushing this C7 ZR1. But listen to how fast the tranny shifts. It's pretty quick and the RPM doesn't drop.
I wonder how much better and quicker the C8 DSG is going to be over this tranny?

https://www.youtube.com/watch?time_c...&v=hBFKu3poI9Y

[SheepDog]

Your very interesting question might be framed in another way. What comparisons and testing did GM do? Comparing the ZR1's automatic against the DCT? Did they used scientific methodology in the comparisons and testing of the ZR1's automatic against the DCT? Did they choose the best one for the job? The fastest? The most reliable?

The cheapest one was the ZR1 automatic which is in house. The DTC is by an outside manufacturer and probably cost more than the in-house auto. The accounting department would naturally prefer the in-house automatic. Therefore the Corvette engineers probably had to make s case for using and buying the DCT from an outside manufacturer. The engineers probably had to fight for the DCT and were successful.

There are comparisons of the ZR1s quick automatic v. the Porsche PDK,[ which Porsche PDK is a DCT]. The Porsche PDK is said to be quicker on the up shifts and very much quicker on the down shifts. The Porsche PDK said to be better at figuring out what to do next, when to do it , and doing it efficiently/effectively.

It is said that the DCTs and Automatic Torque converters are both getting faster . Engineering is improving all forms of transmissions.

But, Which one is the coolest application for the C8 in 2019/20? At least until C8 figures out whether and how to make the manual work in the C8. The tranny that contributes the most to the visceral experience of the C8 will be "the coolest". Which one provides the quickest visceral experience and satisfaction.

The Corvette team has made a determination. Can we disprove their choice. The DCT.

[Z_Rocks]

Your very interesting question might be framed in another way.

Thank you Sir. Your answer was well analyzed and received.

[meyerweb]

Another factor: the 8 speed is said to be very quick when shifting itself, but much, much slower reacting to the paddles. The DCT should respond very quickly either way.

[JB]

Full on track performance the gm automatic torque convertor transmissions when left to their own are impressive.

the problem or fact is...at part throttle or less than track situation the torque convertor automatic was from a driver interaction perspective very much inferior...so gm finally listened to what consumers want...

at 7 tenths....at 4 tenths....at 10 tenths...the dct just is more communicative and offers a much more direct connection to the driver...

ive been a big fan of dct s for over a decade for its consistent quick shifts ...both up and down...

i enjoy driving manual transmissions yet i know I am not as capable as the dct in its ability to shift fast ..

dct s computer controlled shifts also allow for fine tuning the engine to offer more ho, more tq, more performance , better fuel efficiency ad lower emissions.

pretty much the greater control of the engine...the easier it is to bring the engine to maximum efficiency...

this oart Im really speaking of the advantages of dct compared to manual transmissions...

one of the aspects Im most excited about the c8 and even the ford gt500 is american performance brands delving into dct s...

besides car magazine writers no longer have the launch techniques their testers used to....

dct s make consistent performance acceleration numbers repeatable by anybody

[Bikerjulio]

I find a bit of conflicting information which I cannot resolve. Certainly I have seen critical videos of the C7 auto that harp on the slowness of the shifting. Yet GM have a 10-speed auto which they claim is the greatest thing out there. Could the Camaro auto be better than what's in the the C7? Is it that it cannot be packaged as a transaxle?

“There is simply nothing like the experience offered with the new 10-speed automatic in the Camaro ZL1,” said Aaron Link, ZL1 lead development engineer. “It delivers nearly instantaneous, lightning-fast shifts that alter your perception of what an automatic transmission can offer in a high-performance vehicle – whether you’re on the street, drag strip or road course.”

The greater overall performance and efficiency are due primarily to the 10-speed’s wider 7.39 overall gear ratio spread, which enhances off-the-line performance with an aggressive first gear ratio of 4.70. Smaller steps between the gears also help the engine maintain the optimal speed for maximum power at almost all vehicle speeds, especially when exiting a corner on a track.

“The gear ratios are so tightly spaced that the transmission is in the right gear and the engine is at the best rpm for transitions from corners to straights,” said Link. “And with the power from the ZL1’s supercharged LT4 engine, the force you feel in your seat as you accelerate out of a turn will put a grin on your face every time.”

Chevrolet testing has shown the ZL1 with the available 10-speed has faster shift times than the Porsche PDK dual-clutch transmission. In fact, the 1-2 upshift is 36-percent quicker than the PDK, while the 2-3 and 3-4 upshifts are 27-percent and 26-percent quicker, respectively.

“You touch the paddle and the gear changes with immediacy,” said Link. “The shifts happen so quickly and without delay that it almost feels like an extension of your reflexes. It’s a much more involving experience for the driver that really helps improve confidence and performance on the track.”

https://media.chevrolet.com/media/us...chevrolet.html

[SheepDog]

The C8 may have locked in on the DCT before the 10 speed was developed and there's no going back. C8 has been in testing for years now. The Germans are also said to have developed autos that equal or out perform DCTs in some applications.

But GM also said that the 8 speed was faster than the PDK. Guess they kept at it until they got it.

Those DCTs not only shift fast, in the isolated shift function, but down shifts from 8th to 1st faster than "Grammaw" can fall down the steps. . And sounds like that too. And sounds like a 50 cal machine gun doing it.
Kind of exciting, entertaining sounds when the Ferraris do it , not when Gram-maw does or not same excitement. I suppose that the 10 has its own rival rock band. And down shifts dramatically also.

think the 10 is not in a transaxle form,

[Z_Rocks]

And sounds like a 50 cal machine gun doing it.

In another post that I recently posted, This Porsche GT3 took off from a traffic light and I tried to stay with him. The road was near tall industrial buildings and he was going full throttle and every time he hit that pedal, it sounded like a sweet gun shot. Absolute zero RPM drop by the sound of the engine. And when he got to the end, he did a down shift and THAT sounded like 50 cal.

In one of the videos of C8R that was running at night, it also sounded the same way.
Removing that resonator from stock exhaust, it will create an orchestra...

[SheepDog]

In another post that I recently posted, This Porsche GT3 took off from a traffic light and I tried to stay with him. The road was near tall industrial buildings and he was going full throttle and every time he hit that pedal, it sounded like a sweet gun shot. Absolute zero RPM drop by the sound of the engine. And when he got to the end, he did a down shift and THAT sounded like 50 cal.

In one of the videos of C8R that was running at night, it also sounded the same way.
Removing that resonator from stock exhaust, it will create an orchestra...

there is video on another thread "C8 Visits he Bash . . . " . Shows the C8 at the circle at the Bash. Revving the engine like out of gear. while driving. Can DCTs do that. The Lt2 Sounds like a Wolf. Engine sounds husky and aggressive. Think the base ca is going to be a bit on the leanMean side. Banging gear shifts at the end.

[Mobius]

there is video on another thread "C8 Visits he Bash . . . " . Shows the C8 at the circle at the Bash. Revving the engine like out of gear. while driving. Can DCTs do that. The Lt2 Sounds like a Wolf. Engine sounds husky and aggressive. Think the base ca is going to be a bit on the leanMean side. Banging gear shifts at the end.

https://www.midenginecorvetteforum.c...4192#post34192

[Busa Dave]

Your very interesting question might be framed in another way. What comparisons and testing did GM do? Comparing the ZR1's automatic against the DCT? Did they used scientific methodology in the comparisons and testing of the ZR1's automatic against the DCT? Did they choose the best one for the job? The fastest? The most reliable?

The cheapest one was the ZR1 automatic which is in house. The DTC is by an outside manufacturer and probably cost more than the in-house auto. The accounting department would naturally prefer the in-house automatic. Therefore the Corvette engineers probably had to make s case for using and buying the DCT from an outside manufacturer. The engineers probably had to fight for the DCT and were successful.

There are comparisons of the ZR1s quick automatic v. the Porsche PDK,[ which Porsche PDK is a DCT]. The Porsche PDK is said to be quicker on the up shifts and very much quicker on the down shifts. The Porsche PDK said to be better at figuring out what to do next, when to do it , and doing it efficiently/effectively.

It is said that the DCTs and Automatic Torque converters are both getting faster . Engineering is improving all forms of transmissions.

But, Which one is the coolest application for the C8 in 2019/20? At least until C8 figures out whether and how to make the manual work in the C8. The tranny that contributes the most to the visceral experience of the C8 will be "the coolest". Which one provides the quickest visceral experience and satisfaction.

The Corvette team has made a determination. Can we disprove their choice. The DCT.

Interesting that you would make the statement that in house manufacturing and development is cheaper. Outsourcing to the best in class only makes sense---to many unknowns the product lines I am familiar with are much more sophisticated that anything in the automotive industry and we outsourced starting in 1993! It is still done except on a larger scale for new products.

[SheepDog]

Interesting that you would make the statement that in house manufacturing and development is cheaper. Outsourcing to the best in class only makes sense---to many unknowns the product lines I am familiar with are much more sophisticated that anything in the automotive industry and we outsourced starting in 1993! It is still done except on a larger scale for new products.

Ford and GM shared development cost on the 10 speed. Why? Nothing like it on the market? No industry alternative? Do they contract actual production out? Scale?

Chevy dos at least some of the engine assembly. The parts are done outside but who does the engine design. Seems that chevy is somewhat of an engine supplier with all the crate business. Scale?

the DCT is small scale !

Does that say that GM intends to make a lot of Blackwing . doing it at home.

[John]

Having taken the Plant tour three days ago, I am still in awe at how the Powertrain Build Center has grown, and grown and grown over the last two years. It is now a very size-able component within the Plant. Hard for any outsider to quantity accurate how much its square footage has increased, but my best guess is that it is now 250% is size compared to my last Plant tour in the summer of 2017.

[Busa Dave]

Ford and GM shared development cost on the 10 speed. Why? Nothing like it on the market? No industry alternative? Do they contract actual production out? Scale?

Chevy dos at least some of the engine assembly. The parts are done outside but who does the engine design. Seems that chevy is somewhat of an engine supplier with all the crate business. Scale?

the DCT is small scale !

Does that say that GM intends to make a lot of Blackwing . doing it at home.

The development of the performance envelope and a size envelope which is done in house. Then the decision is made on how many will ultimately be built not just for one year but for the production quantity as an estimate which absolutely drives cost and ultimately procurement decisions. From that is either contracted on a single source basis or maybe a competition in some cases. Know that in today's world competitive procurements specific evaluation criteria are not as heavily weighted on cost as one might think with new complex development items. Yes it is a specific component however, risk, financial stability, program management and previous experience on other products etc. for example make up the weighted criteria.

The joint development process is tremendously complicated legally additionally, in the transmission you mentioned above yes it is a very competitive segment of both manufacturers HOWEVER, do you think Ford and GM would jointly develop a DCT transmission that would be used on both the C8 and the GT? There is not enough volume there and this is the flagship of both corporations. This is not really an area that would lend itself to a cost savings utilizing a joint development effort additionally, the GT is a very low production vehicle compared to the Corvette which is mass produced.

[SheepDog]

The development of the performance envelope and a size envelope which is done in house. Then the decision is made on how many will ultimately be built not just for one year but for the production quantity as an estimate which absolutely drives cost and ultimately procurement decisions. From that is either contracted on a single source basis or maybe a competition in some cases. Know that in today's world competitive procurements specific evaluation criteria are not as heavily weighted on cost as one might think with new complex development items. Yes it is a specific component however, risk, financial stability, program management and previous experience on other products etc. for example make up the weighted criteria.

The joint development process is tremendously complicated legally additionally, in the transmission you mentioned above yes it is a very competitive segment of both manufacturers HOWEVER, do you think Ford and GM would jointly develop a DCT transmission that would be used on both the C8 and the GT? There is not enough volume there and this is the flagship of both corporations. This is not really an area that would lend itself to a cost savings utilizing a joint development effort additionally, the GT is a very low production vehicle compared to the Corvette which is mass produced.

Thank for your insight.