Do all DCT's operate in the same manner?
Thread Starter
Race Director
Joined: Oct 2000
Posts: 14,064
Likes: 1,166
From: N. Alabama
Do all DCT's operate in the same manner?
Supposedly this will kill the DCT's in short order:
https://thenewswheel.com/4-mistakes-...-transmission/
https://thenewswheel.com/4-mistakes-...-transmission/
Race Director
Joined: Mar 2007
Posts: 11,395
Likes: 8,559
Clearly not all DCTs work the same way. A comparison of what the referenced article says with what the C8 Owners Manual says shows that. Although written as if its applicable to any DCT, the article is likely only applicable to the DCT with which the author is familiar - and based on his bio, from that article, that might be a Hundai Veloster. He even says his source is this "Sources: Engineering Explained, 2014 Hyundai Veloster owner’s manual". Here are the author's credentials from that article:
"Aaron is unashamed to be a native Clevelander and the proud driver of a Hyundai Veloster Turbo (which recently replaced his 1995 Saturn SC-2). He gleefully utilizes his background in theater, literature, and communication to dramatically recite his own articles to nearby youth. Mr. Widmar happily resides in Dayton, Ohio with his magnificent wife, Vicki, but is often on the road with her exploring new destinations. Aaron has high aspirations for his writing career but often gets distracted pondering the profound nature of the human condition and forgets what he was writing…"
"Aaron is unashamed to be a native Clevelander and the proud driver of a Hyundai Veloster Turbo (which recently replaced his 1995 Saturn SC-2). He gleefully utilizes his background in theater, literature, and communication to dramatically recite his own articles to nearby youth. Mr. Widmar happily resides in Dayton, Ohio with his magnificent wife, Vicki, but is often on the road with her exploring new destinations. Aaron has high aspirations for his writing career but often gets distracted pondering the profound nature of the human condition and forgets what he was writing…"
Thread Starter
Race Director
Joined: Oct 2000
Posts: 14,064
Likes: 1,166
From: N. Alabama
I don't have a C8 and probably never will. So I guess the answer to my question is simply not all DCT's have the same characteristics. I have to wonder which one's are common to the characteristics in the article quoted? I hope the manual for the C8 is very detailed and all owners read it thoroughly. I can't even find a dealership after three different visits to different ones that knows how to properly refresh the fluid in my C7 ZR1 A8 transmission. Not to mention proper caster spec on the rear, yes, Caster on the rear. And if you think that is an iffy proposition, just wait until your first alignment on the C8. You might enquire of the service writer the procedure before turning your car over to them and ask if they have invested in the correct gauge just to make sure they know what they are doing.
Le Mans Master
Joined: Jul 2000
Posts: 6,559
Likes: 4,501
From: North Dallas 40 TX
The Corvette owners manual specifically tells you to apply the brake hard and the accelerator fully in launch mode. The is contrary to one of the points of the article. So they are not all programmed the same.
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,982
Likes: 12,383
From: NE South Carolina
I don't have a C8 and probably never will. So I guess the answer to my question is simply not all DCT's have the same characteristics. I have to wonder which one's are common to the characteristics in the article quoted? I hope the manual for the C8 is very detailed and all owners read it thoroughly. I can't even find a dealership after three different visits to different ones that knows how to properly refresh the fluid in my C7 ZR1 A8 transmission. Not to mention proper caster spec on the rear, yes, Caster on the rear. And if you think that is an iffy proposition, just wait until your first alignment on the C8. You might enquire of the service writer the procedure before turning your car over to them and ask if they have invested in the correct gauge just to make sure they know what they are doing.
NO issues except for the rear caster you are referring to where a special gauge is needed. UNLESS tracking I would not let the average tech touch the rear caster adjustment- can screw it up! If tracking only go to a shop who knows what they are doing AND has done it before. Typically a race shop. Otherwise all other adjustments like any other car.
Tremec bought a high-tech automotive design and development organization HOERBIGER Drivetrain Mechatronics BVBA located in Loppem, Belgium in ~2011. HOERBIGER products and software solutions are found in leading European sports cars, including Ferrari Italia 485, AMG SLS and McLaren MP4-12C.
They no doubt have dealt with all the issues. As Tadge said no issue letting the 1st gear clutch slip slighlty as it does at a red light. The trans is robust! Heck Emilia Hartford has pushed her C8 engine to 1000 hp. As I recall other than adding HD clutches and beefier axles she has not blow-up the DCT!
Last edited by JerryU; Apr 11, 2022 at 01:45 PM.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
And in those cars there is a tolerance called PIS ― Punto Incipiente Slittamento or point of initial slip ― which if misaligned causes the clutch to slip all the time, wearing it out prematurely.
This is not a transmission defect. They typically last forever.
Ray
Safety Car
Joined: Jul 2019
Posts: 4,079
Likes: 2,414
From: Florida
It's not the transmission in those cars, it's the clutch actuator. They have throw-out bearings. The C8 DCT does not use a throw-out bearing, it utilizes 8 pistons which force the driven disk against the flywheel.
And in those cars there is a tolerance called PIS ― Punto Incipiente Slittamento or point of initial slip ― which if misaligned causes the clutch to slip all the time, wearing it out prematurely.
This is not a transmission defect. They typically last forever.
Ray
And in those cars there is a tolerance called PIS ― Punto Incipiente Slittamento or point of initial slip ― which if misaligned causes the clutch to slip all the time, wearing it out prematurely.
This is not a transmission defect. They typically last forever.
Ray
The tremec does not have pistons actuating the clutches. They are fluid actuated like all dcts. The fluid is controlled by 8 solenoids on the clutch side.
Last edited by bhvrdr; Apr 22, 2022 at 06:41 PM.
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
Those cars all use dcts now (porsche always did). The dct in those cars do not have clutch forks or throw out bearings. They're wet sytems that use fluid to actuate them. They also are very robust and generally require less maintenance than our tremec.
The tremec does not have pistons actuating the clutches. They are fluid actuated like all dcts. The fluid is controlled by 8 solenoids on the clutch side.
The tremec does not have pistons actuating the clutches. They are fluid actuated like all dcts. The fluid is controlled by 8 solenoids on the clutch side.
"Next in line are the two normally open wet clutches positioned concentrically to save space. Hydraulic pistons [emphasis added] rotating with the clutches force them into engagement when commanded to do so by the transaxle's electronic control module."
Do you know something that the Society of Automotive Engineers is unaware of? Or are you gonna climb further out on that very thin limb?
Ray
Thread Starter
Race Director
Joined: Oct 2000
Posts: 14,064
Likes: 1,166
From: N. Alabama
In my above post citing an involved procedure for wheel alignment on the C8, I simply find 3 hours to be a rather inordinate procedure and fairly expensive, I would assume.
https://www.corvetteblogger.com/2021...-take-so-long/
https://www.corvetteblogger.com/2021...-take-so-long/
Safety Car
Joined: Jul 2019
Posts: 4,079
Likes: 2,414
From: Florida
I'm quoting from the SAE "Special Report: Engineering the C8 Corvette" Inside Tremec's Supercar DCT pp 21:
"Next in line are the two normally open wet clutches positioned concentrically to save space. Hydraulic pistons [emphasis added] rotating with the clutches force them into engagement when commanded to do so by the transaxle's electronic control module."
Do you know something that the Society of Automotive Engineers is unaware of? Or are you gonna climb further out on that very thin limb?
Ray
"Next in line are the two normally open wet clutches positioned concentrically to save space. Hydraulic pistons [emphasis added] rotating with the clutches force them into engagement when commanded to do so by the transaxle's electronic control module."
Do you know something that the Society of Automotive Engineers is unaware of? Or are you gonna climb further out on that very thin limb?
Ray
What i am saying is that the dct in all the cars you mentioned are in fact not using clutch forks and throwout bearings. They are hydraulically actuated (fluid activated) exactly like the c8 tremec. They use springs to open and hydraulic fluid to close. Yes there are bearings but they are activated by hydraulic fluid just like the cars you said use clutch forks and throwout bearings.
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
In my above post citing an involved procedure for wheel alignment on the C8, I simply find 3 hours to be a rather inordinate procedure and fairly expensive, I would assume.
https://www.corvetteblogger.com/2021...-take-so-long/
https://www.corvetteblogger.com/2021...-take-so-long/
Ray
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
What i am saying is that the dct in all the cars you mentioned are in fact not using clutch forks and throwout bearings. They are hydraulically actuated (fluid activated) exactly like the c8 tremec. They use springs to open and hydraulic fluid to close. Yes there are bearings but they are activated by hydraulic fluid just like the cars you said use clutch forks and throwout bearings.
And just to be clear, "hydraulically actuated" is another way to say fluid activated.
Yes there are bearings but they are activated by hydraulic fluid ...
And what about the pistons used to close the clutch? You said they didn't exist, remember?
The tremec does not have pistons actuating the clutches.
And I'm sure Porsche owners, especially those up to 1980, will be thrilled to hear that they have a DCT because you said
Those cars all use dcts now (porsche always did).
Do a little homework before you shoot from the hip. And brush up on the rules of capitalization.
Ray
Safety Car
Joined: Jul 2019
Posts: 4,079
Likes: 2,414
From: Florida
Not "activated" lol. .... "Actuated". Sorry about that. You got the idea i think.
Again, actuated. Just like your brake pistons are compressed against the pads via hydraulic fluid. Hope that helps you to be able to visualize it.
I have no idea why you are discussing a manual transmission with single dry clutch and were stating dual cutch transmissions from Ferrari, Lamborghini and Porsche are similar.
It's not the transmission in those cars, it's the clutch actuator. They have throw-out bearings. The C8 DCT does not use a throw-out bearing, it utilizes 8 pistons which force the driven disk against the flywheel.
PIS ― Punto Incipiente Slittamento or point of initial slip
PIS ― Punto Incipiente Slittamento or point of initial slip
Again there is no throwout bearing or clutch fork on dual clutch transmissions from Ferrari, Lamborghini or Porsche.
Last edited by bhvrdr; Apr 23, 2022 at 12:40 AM.
Racer
Joined: Nov 2021
Posts: 482
Likes: 231
From: Costa Mesa, CA
What part of "closed by hydraulic pressure on rotating pistons" did you not understand when you highlighted it to prove that the transmission has no pistons? Let me restate that: You circled the description that says it uses pistons to close the clutch in order to prove that it doesn't use pistons. You get that right? That is what started this discussion.
Seriously?
And the C8 transmission is a manual transmission. It's does not have a torque converter. It has a multi-plate friction clutch, you just don't have to engage/disengage it.
And Porsche did not start using the PDK transmission until 2009. So much for "Porsche always used it".
Ray
Seriously?
And the C8 transmission is a manual transmission. It's does not have a torque converter. It has a multi-plate friction clutch, you just don't have to engage/disengage it.
And Porsche did not start using the PDK transmission until 2009. So much for "Porsche always used it".
Ray
E-Ray, 3LZ, ZER, LIFT
Joined: Sep 2007
Posts: 34,982
Likes: 12,383
From: NE South Carolina
I'm quoting from the SAE "Special Report: Engineering the C8 Corvette" Inside Tremec's Supercar DCT pp 21:
"Next in line are the two normally open wet clutches positioned concentrically to save space. Hydraulic pistons [emphasis added] rotating with the clutches force them into engagement when commanded to do so by the transaxle's electronic control module."
Do you know something that the Society of Automotive Engineers is unaware of? Or are you gonna climb further out on that very thin limb?
Ray
"Next in line are the two normally open wet clutches positioned concentrically to save space. Hydraulic pistons [emphasis added] rotating with the clutches force them into engagement when commanded to do so by the transaxle's electronic control module."
Do you know something that the Society of Automotive Engineers is unaware of? Or are you gonna climb further out on that very thin limb?
Ray
Safety Car
Joined: Jul 2019
Posts: 4,079
Likes: 2,414
From: Florida
What part of "closed by hydraulic pressure on rotating pistons" did you not understand when you highlighted it to prove that the transmission has no pistons? Let me restate that: You circled the description that says it uses pistons to close the clutch in order to prove that it doesn't use pistons. You get that right? That is what started this discussion.
Seriously?
And the C8 transmission is a manual transmission. It's does not have a torque converter. It has a multi-plate friction clutch, you just don't have to engage/disengage it.
And Porsche did not start using the PDK transmission until 2009. So much for "Porsche always used it".
Ray
Seriously?
And the C8 transmission is a manual transmission. It's does not have a torque converter. It has a multi-plate friction clutch, you just don't have to engage/disengage it.
And Porsche did not start using the PDK transmission until 2009. So much for "Porsche always used it".
Ray
You said...
..two normally open concentric clutches opened by springs, closed by hydraulic pressure
Most people would just thank me for providing you the resource like you requested. No problem Ray.
And the c8 uses a tremec tr9080 dual clutch automated transmission Ray. Unfortunately there is no manual option sorry.
And again Ferrari Lamborghini and Porsche dct do not have throwout bearings or clutch forks.