Jan 15, 2006 4:33:05 AM
- Van911Turbo
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Board: Porsche - 911 - 997 - Turbo
Language: English
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Jan 15, 2006 9:31:39 AM
- guy2
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- Loc: germany
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- Reply to: Van911Turbo
Re: What are the difference between tip and PDK?
i try, but my english is not too good.
the tiptronic is a normal (old) automatic transmission with 5gears. it consumes around 5% of the engines power due to drivetrain loss in the tiptronic.
the PDK = porsche double clutch transmission is basicly a normal manual transmission, so there is no power loss compared to the tiptronic. BUT basicly this thing has TWO gearboxes. the first one is responsable for the 1s, 3rd and 5th gear and the second for the 2nd,4th and 6th gear. each of this "little" boxes has its own clutch.
imagine you are driving in first gear, so the clutch to the first gearbox is closed and gear one is selected while obviously the other clutch is opend. BUT there is alredy the second gear in the other box selected. so while you change gear from 1st to 2nd, the system just needs to open the first clutch and exactly in the same time the system closes the clutch to the second gearbox. so there is no pause during shifting, it is very fast and smooth.
so remember while you are driving in one gear the other box has already selected the next neede gear and both clutches are used at the same time, in a way, it is like a handshake.
i hope my description was understandable.
the tiptronic is a normal (old) automatic transmission with 5gears. it consumes around 5% of the engines power due to drivetrain loss in the tiptronic.
the PDK = porsche double clutch transmission is basicly a normal manual transmission, so there is no power loss compared to the tiptronic. BUT basicly this thing has TWO gearboxes. the first one is responsable for the 1s, 3rd and 5th gear and the second for the 2nd,4th and 6th gear. each of this "little" boxes has its own clutch.
imagine you are driving in first gear, so the clutch to the first gearbox is closed and gear one is selected while obviously the other clutch is opend. BUT there is alredy the second gear in the other box selected. so while you change gear from 1st to 2nd, the system just needs to open the first clutch and exactly in the same time the system closes the clutch to the second gearbox. so there is no pause during shifting, it is very fast and smooth.
so remember while you are driving in one gear the other box has already selected the next neede gear and both clutches are used at the same time, in a way, it is like a handshake.
i hope my description was understandable.
Re: What are the difference between tip and PDK?
Quote:
BD 997 said:
do you think anyone will buy tip if PDK does not come out 1st year production?
Yes. A lot of people don't really care about performance all that much and just want the newest toy to show off (just look at how many 996TTs there were with Tips). Once PDK gets here, it will be a different story, but as long as the Tiptronic is the only automatic option, there will be buyers for it.
Jan 25, 2006 5:16:18 PM
- Joost
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Re: What are the difference between tip and PDK?
Quote:
Joost said:
Ok, for upshifting I understand... one gearbox is in 3, the other in four... you drive in gear 3... what if you want to decelerate and select 2nd gear?
-Joost-
That example is not quite right.
On one shaft you always have gears 1,3,5 and the other shaft provides gearwheels 2,4,6. there is no difference for upshift or downshift, it is the same process.
If you are in 3 the other shaft has 2,4,6 rotating for next gear. Which one is actually chosen depends on your selection. That particular gear is engaged, the others on the same shaft idle. The duble clutch allows the transition between shaft one and two.
Not sure if text explanation clarifies the concept. Maybe there is some animation somewhere on the next (Audi, VW??).
Re: What are the difference between tip and PDK?
There's no question that PDK will eventually be a superior transmission. However, I would be leery to get one on its first year as there may be still bugs in it.
However efficient the PDK may be it will not be without losses. All transmissions, even manuals do have losses.
Up in the thread someone says that the Tip II loss is 5%. That may be true, and it is not a big loss. Actually, I'm told that the torque converter on the Tip II is only used in 1st gear. The transmission behaves like a manual from second up - a very efficient and very fast transmission, actually.
However efficient the PDK may be it will not be without losses. All transmissions, even manuals do have losses.
Up in the thread someone says that the Tip II loss is 5%. That may be true, and it is not a big loss. Actually, I'm told that the torque converter on the Tip II is only used in 1st gear. The transmission behaves like a manual from second up - a very efficient and very fast transmission, actually.
Jan 26, 2006 1:57:00 AM
- Avantgarde
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- Loc: City State
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- Reply to: ADias
Re: What are the difference between tip and PDK?
Quote:
ADias said:
Actually, I'm told that the torque converter on the Tip II is only used in 1st gear. The transmission behaves like a manual from second up - a very efficient and very fast transmission, actually.
Perhaps what you mentioned could explain the slight jerkiness experience during gear shifts in the Slushbox.
Anyone can confirm?
Jan 26, 2006 4:48:15 AM
- cookie monster
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- Loc: US , United States
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- Registered on: Dec 8, 2005
- Reply to: Avantgarde
Re: What are the difference between tip and PDK?
Anyone knows anything about the auto on SLR? It is supposedly a superfast supercar with an auto transmission and it is 5 gear I think. I owned the SLK 350 7G tronic and that gear box (1st year production) including the one in the CLS weren't very smooth. It had some jerkiness to it.
Jan 26, 2006 4:50:12 AM
- cookie monster
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- Loc: US , United States
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- Reply to: ADias
Re: What are the difference between tip and PDK?
Quote:
ADias said:
There's no question that PDK will eventually be a superior transmission. However, I would be leery to get one on its first year as there may be still bugs in it.
However efficient the PDK may be it will not be without losses. All transmissions, even manuals do have losses.
Up in the thread someone says that the Tip II loss is 5%. That may be true, and it is not a big loss. Actually, I'm told that the torque converter on the Tip II is only used in 1st gear. The transmission behaves like a manual from second up - a very efficient and very fast transmission, actually.
Actually, when I drove the tipronic (supposedly 3rd generation) on the test drive, it amazed me as to how smooth it felt compared to the 7G tronic. The problem with the 7G was that sometimes, the box didn't know what gears to select. The 5 speed tiptronic on the Porsche feels solid and smooth even though it maybe an older technology compared to PDK. I am also wary about 1st year PDK deployment on all lineup on Porsche.
Re: What are the difference between tip and PDK?
yah,
I think your explanation is great. Thank you! This clarifies some of the questions I had. However, one more is still in my head.
How does the system react when the driver wants to shift from one gear on the same shaft to another? For example, going from 6th to 4th directly?
Will the electronic have to go through the gear in between (in my example above this would be 5th) or is there another way allowing to 'jump' one gear?
TIA
Gregor
I think your explanation is great. Thank you! This clarifies some of the questions I had. However, one more is still in my head.
How does the system react when the driver wants to shift from one gear on the same shaft to another? For example, going from 6th to 4th directly?
Will the electronic have to go through the gear in between (in my example above this would be 5th) or is there another way allowing to 'jump' one gear?
TIA
Gregor
Jan 26, 2006 3:37:11 PM
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Ron (Houston)
- Rennteam Moderator
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- Loc: Houston, TX , United States
- Posts: 8812, Gallery
- Registered on: Apr 10, 2002
- Reply to: guy2
Re: What are the difference between tip and PDK?
Quote:
guy2 said:
i try, but my english is not too good.
the tiptronic is a normal (old) automatic transmission with 5gears. it consumes around 5% of the engines power due to drivetrain loss in the tiptronic.
the PDK = porsche double clutch transmission is basicly a normal manual transmission, so there is no power loss compared to the tiptronic. BUT basicly this thing has TWO gearboxes. the first one is responsable for the 1s, 3rd and 5th gear and the second for the 2nd,4th and 6th gear. each of this "little" boxes has its own clutch.
imagine you are driving in first gear, so the clutch to the first gearbox is closed and gear one is selected while obviously the other clutch is opend. BUT there is alredy the second gear in the other box selected. so while you change gear from 1st to 2nd, the system just needs to open the first clutch and exactly in the same time the system closes the clutch to the second gearbox. so there is no pause during shifting, it is very fast and smooth.
so remember while you are driving in one gear the other box has already selected the next neede gear and both clutches are used at the same time, in a way, it is like a handshake.
i hope my description was understandable.
Very well and easy to understand put, well done
.
Re: What are the difference between tip and PDK?
Quote:
Gregor said:
yah,
I think your explanation is great. Thank you! This clarifies some of the questions I had. However, one more is still in my head.
How does the system react when the driver wants to shift from one gear on the same shaft to another? For example, going from 6th to 4th directly?
Will the electronic have to go through the gear in between (in my example above this would be 5th) or is there another way allowing to 'jump' one gear?
TIA
Gregor
You have to sequentially go through all the gears. You cannot "jump" two gears. (With paddles you couldn't select a particular gear anyway.)
Jumping gears is also not advised for normal manuals. For other reasons, but still.
Pros always go through all the gears. You should watch a race driver when he gets from a straight line with top speed in 5th or 6th gear into a narrow curve with second gear. He switches down through all the gears in seconds with tip-toeing.
Re: What are the difference between tip and PDK?
Quote:
Gregor said:
How does the system react when the driver wants to shift from one gear on the same shaft to another? For example, going from 6th to 4th directly?
Will the electronic have to go through the gear in between (in my example above this would be 5th) or is there another way allowing to 'jump' one gear?
TIA
Gregor
I believe PDK is sort of a sequential gearbox, which means that it has to go through all the gears in any case. Or in other words, you can't select a gear directly. You have to tip the selector twice to make it go from 4th to 2nd. No sure though.
Re: What are the difference between tip and PDK?
Quote:
Matt C said:Quote:
Gregor said:
How does the system react when the driver wants to shift from one gear on the same shaft to another? For example, going from 6th to 4th directly?
Will the electronic have to go through the gear in between (in my example above this would be 5th) or is there another way allowing to 'jump' one gear?
TIA
Gregor
I believe PDK is sort of a sequential gearbox, which means that it has to go through all the gears in any case. Or in other words, you can't select a gear directly. You have to tip the selector twice to make it go from 4th to 2nd. No sure though.
no, it is possible - except it won't upshift/downshift as quickly (or smoothly). would be comparable changing gears on a Ferrari F1 or BMW SMG transmission (which works on the same principle, but with only one clutch).
Re: What are the difference between tip and PDK?
From Road & Track...
-----------------------------------
I've saved VW-Audi's Direct Shift Gearbox for last, as it's the newest (see our May 2004 Audi TT/BMW Z4 comparison) and also the most innovative. By the way, DSG also answers to the name of DualTronic; this, at its BorgWarner supplier.
DSG shifts offer essentially uninterrupted transmission of power (in feel, much like a conventional automatic). This is achieved by means of innovative twin-concentric clutches operating within what is otherwise a rather conventional gearbox.
Let's imagine that our Morgan model were DSG. (Please, stop laughing). With DSG, its input shaft consists of an inner shaft containing 1st and 3rd gears and an outer hollow shaft containing 2nd and 4th. The hollow shaft is linked to the outer clutch; the inner one, to the inner clutch.
When 1st gear is selected (by you or the computer), both the 1st- and 2nd-gear dog clutches are engaged. This would cause gearbox chaos but for action of the twin concentric clutches: With 1st gear selected, the inner clutch is engaged, but the outer one is disengaged. Thus, think of 2nd gear as being only pre-engaged.
Then comes the 1-2 shift, be it driver- or computer-initiated. It requires nothing more than disengagement of the inner clutch (freeing 1st gear) and engagement of the outer one (bringing 2nd into the transmission of power). That is, each of these gears is already locked to its appropriate input shaft, 1st to the inner one, 2nd to the hollow one.
Programmed logic identifies what happens next. If the car is accelerating, the 2-3 shift is preselected by locking 3rd gear to the inner shaft (after unlocking 1st), the inner twin-clutch still disengaged. If computer logic identifies deceleration, 1st gear gets locked in preselection of a 2-1 downshift. The appropriate shift occurs seamlessly with the timed engagement of one clutch and disengagement of another.
What's truly amazing is how transparently these actions occur.
A DSG/DualTronic tidbit on gasoline versus diesel: Supplier BorgWarner sees this gearbox as offering a gasoline-powered car perhaps 5-percent better fuel economy compared with its automatic-equipped counterpart. But it cites as much as 15-percent better diesel economy. Why the difference? Diesels produce their torque - and a lot of it - at relatively low rpm. And this is where conventional planetary gearsets (the heart of automatics, you'll recall) do not operate very efficiently.
-----------------------------------
I've saved VW-Audi's Direct Shift Gearbox for last, as it's the newest (see our May 2004 Audi TT/BMW Z4 comparison) and also the most innovative. By the way, DSG also answers to the name of DualTronic; this, at its BorgWarner supplier.
DSG shifts offer essentially uninterrupted transmission of power (in feel, much like a conventional automatic). This is achieved by means of innovative twin-concentric clutches operating within what is otherwise a rather conventional gearbox.
Let's imagine that our Morgan model were DSG. (Please, stop laughing). With DSG, its input shaft consists of an inner shaft containing 1st and 3rd gears and an outer hollow shaft containing 2nd and 4th. The hollow shaft is linked to the outer clutch; the inner one, to the inner clutch.
When 1st gear is selected (by you or the computer), both the 1st- and 2nd-gear dog clutches are engaged. This would cause gearbox chaos but for action of the twin concentric clutches: With 1st gear selected, the inner clutch is engaged, but the outer one is disengaged. Thus, think of 2nd gear as being only pre-engaged.
Then comes the 1-2 shift, be it driver- or computer-initiated. It requires nothing more than disengagement of the inner clutch (freeing 1st gear) and engagement of the outer one (bringing 2nd into the transmission of power). That is, each of these gears is already locked to its appropriate input shaft, 1st to the inner one, 2nd to the hollow one.
Programmed logic identifies what happens next. If the car is accelerating, the 2-3 shift is preselected by locking 3rd gear to the inner shaft (after unlocking 1st), the inner twin-clutch still disengaged. If computer logic identifies deceleration, 1st gear gets locked in preselection of a 2-1 downshift. The appropriate shift occurs seamlessly with the timed engagement of one clutch and disengagement of another.
What's truly amazing is how transparently these actions occur.
A DSG/DualTronic tidbit on gasoline versus diesel: Supplier BorgWarner sees this gearbox as offering a gasoline-powered car perhaps 5-percent better fuel economy compared with its automatic-equipped counterpart. But it cites as much as 15-percent better diesel economy. Why the difference? Diesels produce their torque - and a lot of it - at relatively low rpm. And this is where conventional planetary gearsets (the heart of automatics, you'll recall) do not operate very efficiently.
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