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Nov 14, 2007 1:26:54 PM
- silvershadow
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- Loc: Zuerich, Switzerland , Switzerland
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Re: For PDK fans...
Quote:
tortesq1 said:
Does Getrag also make the Volkswagon/Audi DSG trannies ? I thought Porsche was going to eventually adopt some sort of modified Audi DSG tranny ?
While I don't know for sure, I suspect Porsche wants to develop their own system and make sure that it works well, with low warranty costs. I also think they don't want to pay a high price for someone else's PDK version or pay royalties for it. They want their own, patented, which they then may license to others for fees. Again, this is just a guess based on Porsche's history of inventing and patenting new technologies and then using them and eventually licensing them to others.
Jim
Re: For PDK fans...
DSG compatible w/high-tq is seen in Veyron...but has cost/wt issues...and don't know if it's reliable/robust....or very sophisticated in inter-linking vs various chassis computer networks....
My guess is fast/smart autoboxes will be solution for fastest/smoothest/safest/most robust gearboxes, esp vs high-tq motors and very advanced chassis computer networks.....intuitively (as a non-engineer), suspect that human input re: gear selection will only slow/destabilize an advanced drivetrain/chassis computer network which is actively assessing chassis stability vs road surface and dynamics (steering/brakes/throttle) inputs of driver.....
Would speculate era of Luddite box will last 2-3 more yrs, to preserve sales to elder, nostalgia-seekers....and paddleshifters (or placeboshifters) will remain around for guys who will take a few yrs to admit that a smart, fast computer network will beat their alleged shifting choices/skills 99%+ of time, esp on bumpy, imperfect public roads....
My guess is fast/smart autoboxes will be solution for fastest/smoothest/safest/most robust gearboxes, esp vs high-tq motors and very advanced chassis computer networks.....intuitively (as a non-engineer), suspect that human input re: gear selection will only slow/destabilize an advanced drivetrain/chassis computer network which is actively assessing chassis stability vs road surface and dynamics (steering/brakes/throttle) inputs of driver.....
Would speculate era of Luddite box will last 2-3 more yrs, to preserve sales to elder, nostalgia-seekers....and paddleshifters (or placeboshifters) will remain around for guys who will take a few yrs to admit that a smart, fast computer network will beat their alleged shifting choices/skills 99%+ of time, esp on bumpy, imperfect public roads....
Re: For PDK fans...
Now that Porsche 'owns' VW/Audi, don't think they will need to pay any royalties to use their PDK, but Audi's version is rated for light duty, it does not have the capacity to handle Porsche's engines, especially the Turbo's. Veyron's one is a specially developed one off just for that car, built like a tank and weights like one too, hence it will be unsuitable fo 911 applications.
Re: For PDK fans...
Neither Porsche or Audi did develop current DSG gearboxes. It was done by BorgWarner and Getrag. And there are several version as you can see on Gertag web site. Current maximum is 750Nm for 7speed version. Only one problem with ALL DSG gearboxes(included the one in new Nissan GT-R)-they are all very, very heavy. Even heavier then current TIP in 997 Turbo...
Nov 17, 2007 10:47:12 AM
- silvershadow
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- Loc: Zuerich, Switzerland , Switzerland
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Re: For PDK fans...
What's the reason of having them so heavy?
Margin of safety is left a lot higher to account for small gear collisions? Rattle more pronounced? Dual clutch mechanism carrying with it a lot more components?
I'm not a gearbox expert but i'd like to know more on this argument
Margin of safety is left a lot higher to account for small gear collisions? Rattle more pronounced? Dual clutch mechanism carrying with it a lot more components?
I'm not a gearbox expert but i'd like to know more on this argument
Nov 17, 2007 10:52:56 AM
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Whoopsy
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- Reply to: silvershadow
Re: For PDK fans...
Quote:
Whoopsy said:
Veyron's system has to be beefy enough to handle 1000hp, normal Audi ones are quite a bit lighter but they only had to do with around 200-250hp.
Whoopsy,
Did you look at Getrag web site?
NO? Of course. Since new DSGs can handle up to 750Nm(HP are NOT important at all!)...
http://www.getrag.de/313.1?_search_=_DCT_&_results_=0&_offset_=0
Porsche will use costum version of Getrag 456 DCT. BTW, Getrag supplies manual gearbox for 997 Turbo, GT2 and GT3.
Nov 17, 2007 11:09:20 AM
- KresoF1
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Re: For PDK fans...
Quote:
silvershadow said:
What's the reason of having them so heavy?
Margin of safety is left a lot higher to account for small gear collisions? Rattle more pronounced? Dual clutch mechanism carrying with it a lot more components?
I'm not a gearbox expert but i'd like to know more on this argument
Design wise DCT are always much heavier then manual. Few critical issues for DCT are:
-much more heat
-way more complex layout
-much stronger gearbox components
In Golf GTI DSG is 35kg heavier then manual. In 997 Turbo it will be around 50kg. PDK 997 Turbo will be marginally faster at high speed then current TIP version but, it will be faster then manual(with LSD) on the track because PDK will use LSD(as option or standard remain to be seen). Porsche at least hopes so...
Re: For PDK fans...
Quote:
KresoF1 said:
PDK 997 Turbo will be marginally faster at high speed then current TIP version but, it will be faster then manual(with LSD) on the track because PDK will use LSD(as option or standard remain to be seen). Porsche at least hopes so...
Pdk with LSD will be faster(tracktime) than manual with lsd?
Re: For PDK fans...
Quote:
andrea said:Quote:
KresoF1 said:
PDK 997 Turbo will be marginally faster at high speed then current TIP version but, it will be faster then manual(with LSD) on the track because PDK will use LSD(as option or standard remain to be seen). Porsche at least hopes so...
Pdk with LSD will be faster(tracktime) than manual with lsd?
Well, as I already said Porsche(Marketing Department for sure) hopes so!
Re: For PDK fans...
That viewpoint may change in the near future. I grew up playing racing games. Paddle shifters have always felt more natural to me.
We don't see anyone pining for the good old days of non-synchronized gearboxes, do we? In fact, it's only because most of those that did are already dead.
We don't see anyone pining for the good old days of non-synchronized gearboxes, do we? In fact, it's only because most of those that did are already dead.
Re: For PDK fans...
Quote:
KresoF1 said:
Whoopsy,
Did you look at Getrag web site?
NO? Of course. Since new DSGs can handle up to 750Nm(HP are NOT important at all!)...
http://www.getrag.de/313.1?_search_=_DCT_&_results_=0&_offset_=0
Porsche will use costum version of Getrag 456 DCT. BTW, Getrag supplies manual gearbox for 997 Turbo, GT2 and GT3.
Actually I did, and I was too lazy to look up Audi and Veyron's torque output so I just use the hp rating, for argument sake it was enough. Didn't think someone is gonna use that against me
Plus I was just responding to someone on using Audi/VW's version or the Veyron's version.Anyway, the only one from Getrag with enough capacity is the one for mid or front engine application, so for 911 duty it will be a different version than that.
Believe me when I say I am excited by the prospect of PDK, it's gonna be lightyears ahead of the manual. Imagine any one of us here in a PDK car is gonna shift much faster and more precise than WR in a manual car
Re: For PDK fans...
Quote:
Whoopsy said:Quote:
KresoF1 said:
Whoopsy,
Did you look at Getrag web site?
NO? Of course. Since new DSGs can handle up to 750Nm(HP are NOT important at all!)...
http://www.getrag.de/313.1?_search_=_DCT_&_results_=0&_offset_=0
Porsche will use costum version of Getrag 456 DCT. BTW, Getrag supplies manual gearbox for 997 Turbo, GT2 and GT3.
Actually I did, and I was too lazy to look up Audi and Veyron's torque output so I just use the hp rating, for argument sake it was enough. Didn't think someone is gonna use that against me
Anyway, the only one from Getrag with enough capacity is the one for mid or front engine application, so for 911 duty it will be a different version than that.
Believe me when I say I am excited by the prospect of PDK, it's gonna be lightyears ahead of the manual. Imagine any one of us here in a PDK car is gonna shift much faster and more precise than WR in a manual car
I agree with you. PDK will be great, specially if Porsche offers it with optional LSD. Then facelifted 997 Turbo could indeed become an true icon again for all sportscars enthusiasts.
Re: For PDK fans...
Once the factory begins to use its customers as unwitting Beta testers for PDK transmissions their will be a lot of crying here about PDK clutch failures.
There is no clutch material on the planet that can take millisecond shifts for the same amount of times and miles as a slower shifting Porsche Manual or a Tip. PDK type transmissions have a realtively short life. If Porsche et al. has solved the clutch materials and heat problems I salute them, but I doubt they have.
If you plan to buy a PDK 997TT you better read the fine print on its new car warranty before writing the check.
Both Ferrari and Maserati regulary make customers pay for short lives of their F1 transmissions.
There is no clutch material on the planet that can take millisecond shifts for the same amount of times and miles as a slower shifting Porsche Manual or a Tip. PDK type transmissions have a realtively short life. If Porsche et al. has solved the clutch materials and heat problems I salute them, but I doubt they have.
If you plan to buy a PDK 997TT you better read the fine print on its new car warranty before writing the check.
Both Ferrari and Maserati regulary make customers pay for short lives of their F1 transmissions.
Nov 17, 2007 8:43:43 PM
- Turbo4ever
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Nov 17, 2007 9:08:52 PM
- WR
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Re: For PDK fans...
Doubt manual gearboxes will be extinct in a few years, surely not in europe. People here learn to drive cars with manuals at the local driving schools + most of the people here are short on money due to taxes and low salaries, hence I doubt that people will leave the manual gearboxes for extra 1500 Euro on a regular car.
Automatics are usually used by women or 70 years old german tourists, who rent the most expensive car to try to impress the locals.
Automatics are usually used by women or 70 years old german tourists, who rent the most expensive car to try to impress the locals.
Re: For PDK fans...
We're all missing the point. Automated manual gearboxes will kill the old stick shift on mainstream cars before they do on sports cars.
And not because of superhuman shifting times, but because of fuel economy.
Computer-controlled gearboxes means that an economy car is guaranteed to use the most fuel-efficient RPM and the most fuel-efficient gear at any time. That technology is currently used in hybrid cars, but might be used in any car.
To do so, the car needs some kind of auto box. Traditional auto boxes waste energy, so they're out. That leaves either CVT gearboxes (depending on design), or automated manuals.
Of course, if electric vehicles ever become mainstream, we won't even need gearboxes at all.
And not because of superhuman shifting times, but because of fuel economy.
Computer-controlled gearboxes means that an economy car is guaranteed to use the most fuel-efficient RPM and the most fuel-efficient gear at any time. That technology is currently used in hybrid cars, but might be used in any car.
To do so, the car needs some kind of auto box. Traditional auto boxes waste energy, so they're out. That leaves either CVT gearboxes (depending on design), or automated manuals.
Of course, if electric vehicles ever become mainstream, we won't even need gearboxes at all.
Nov 18, 2007 1:50:10 AM
- x838nwy
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- Loc: umm.....
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- Reply to: silvershadow
Re: For PDK fans...
Quote:
silvershadow said:
What's the reason of having them so heavy?
Margin of safety is left a lot higher to account for small gear collisions? Rattle more pronounced? Dual clutch mechanism carrying with it a lot more components?
I'm not a gearbox expert but i'd like to know more on this argument
a.) The dual clutch itself is very complex. Basically two clutches in one and EACH will have to be able to take the full torque and some. To do so, they'll have to be hefty and I suspect that to keep the inertia of the clutch & flywheel low, pretty small in diameter so they'll both have to be really beefy.
b.) You need a whole bunch of actuators and what not to engage/disengare the gears and clutches. Last I read about them, they use hydraulics to change the gears and if you include fail-safes and other bits and pieces that actually make the thing work, weights go up.
c.) The designs I've seen involve two concentric shafts. My guess would be that to handle a decent amount of torque/vibration/shock loads there's a bit of a packaging problem here in terms of physical size and perhaps even heat dissipation.
d.) I'm pretty sure there's got to be something about the synchronizers that I can't think of (not very familiar with them). Perhaps someone can shed some light (no pun intended
) on this.Generally speaking, there's a heck of a lot of things to stuff into that space. The problem here is that compared to manual or even plain old auto, the technology is very new and so to compare dsg's to a _good_ autobox in every respect is a bit inappropriate. At this stage, imo, it's less to do with Borg Warner or Getrag actually making them lighter, it's an incredible job they managed to make them at all (for high torque applications at such an early stage).
We've been making manuals since the stone age and autos since the 40's and all those engineers have been improving them since day one. As a result, they've become better and better. No doubt dsg/pdk will improve, perhaps at an even greater rate. Technology in materials, electronics and plain old ingenuity will no doubt improve things.
I'm pretty sure it will replace more and more autos in a whole bunch of mass produced cars for reasons mentioned. Plus if you drive a Camry or something, would you truly care how your car is changing gears? So if the dsg proves to be more economical and can feasibly replace autos, then I'm sure manufacturers will go for it.
The performance advantage will attract fans of sports cars. But will it ever completely replace manuals... I can't really say...
Re: For PDK fans...
Wow, IMHO this is *BY FAR* the most negative feature of PDK, per the dictum that weight is the enemy of all sports cars. Manual is already so heavy at 3494 lbs.--to me a major reason why the Turbo doesn't do as well at the track vs. GT3, etc., tip is 3572 lbs., so PDK might cross 3600?!
KresoF1 (or anyone else in-the-know, thanks in advance): Is it true the F1 type shifter in F cars is a much more "efficient" design? Faster shifting and lighter? If so why doesn't Porche head that way? Is reliability a problem with the F1 shifter?
KresoF1 (or anyone else in-the-know, thanks in advance): Is it true the F1 type shifter in F cars is a much more "efficient" design? Faster shifting and lighter? If so why doesn't Porche head that way? Is reliability a problem with the F1 shifter?
Quote:
KresoF1 said:
Neither Porsche or Audi did develop current DSG gearboxes. It was done by BorgWarner and Getrag. And there are several version as you can see on Gertag web site. Current maximum is 750Nm for 7speed version. Only one problem with ALL DSG gearboxes(included the one in new Nissan GT-R)-they are all very, very heavy. Even heavier then current TIP in 997 Turbo...
Re: For PDK fans...
F1 transmission in Ferrari IS a conventional manual gearbox with hydraulic and electronic help on shifting and clutch engage/disengaging.
PDK is a different kind of box, it uses 2 clutches to engage the current gear and the next gear, either up 1 or down 1, as parts goes it already has a second set of clutch and all it's associated hardware.
Advantage is that IF the transmission guess right on your up/down shift, it's much faster and smoother than any conventional gearbox, but if it guesses wrong, there is a time/smoothness penalty to select the correct gear.
So in a way, the dumb F1/conventional gearbox is much simpler, and kinda more efficient because it only follows orders, not guessing what you want.
PDK is a different kind of box, it uses 2 clutches to engage the current gear and the next gear, either up 1 or down 1, as parts goes it already has a second set of clutch and all it's associated hardware.
Advantage is that IF the transmission guess right on your up/down shift, it's much faster and smoother than any conventional gearbox, but if it guesses wrong, there is a time/smoothness penalty to select the correct gear.
So in a way, the dumb F1/conventional gearbox is much simpler, and kinda more efficient because it only follows orders, not guessing what you want.
Re: For PDK fans...
iirc, the Ferrari system takes considerably longer to shift - hundreds of milliseconds in comparison to tens with dsg's. Additionally the shift is potentially a lot smoother with the dsg.
From what I've read/heard Ferrari system can be made to shift pretty quickly too but it'd be very harsh. One suspects that it might cause problems in everyday use and would probably do horrible things to sophisticated systems such as that in the Porshce TT.
Imho, the dsg/pdk is a logical step forward, rather than the 'actuated manual' approach. Weights will come down in the next couple of years and the benefits in smoothness and shift times will be more evident... until true cvt's are sufficient developed, I guess...
From what I've read/heard Ferrari system can be made to shift pretty quickly too but it'd be very harsh. One suspects that it might cause problems in everyday use and would probably do horrible things to sophisticated systems such as that in the Porshce TT.
Imho, the dsg/pdk is a logical step forward, rather than the 'actuated manual' approach. Weights will come down in the next couple of years and the benefits in smoothness and shift times will be more evident... until true cvt's are sufficient developed, I guess...
Re: For PDK fans...
Guys,
that needs a bit of clarification. The DSG box mentioned above weighst about 50 kg more than the manual version and about 20 kg more than the common automatic transmission for those applications. Their efficiency rate is right between manual and automatic transmission, further depending (due to oil cirulation) if using a wet or dry clutch application. We are talking rougly about an efficiency improvement of about 10 percent, which translates into accordingly improving fuel economy and performance. Given an equal development rate, automatic trans. will not exceed those, at least from my point of view!
The F1 transmissions, if driven constantly at short shifting settings, are very unreliable. One can assume that improvements on calibrations and new technology (the projected electric drive support for example) will give that concept a fair share even in the future. Still it is worth to consider that it failed on a broad basis in everyday cars in Europe.
that needs a bit of clarification. The DSG box mentioned above weighst about 50 kg more than the manual version and about 20 kg more than the common automatic transmission for those applications. Their efficiency rate is right between manual and automatic transmission, further depending (due to oil cirulation) if using a wet or dry clutch application. We are talking rougly about an efficiency improvement of about 10 percent, which translates into accordingly improving fuel economy and performance. Given an equal development rate, automatic trans. will not exceed those, at least from my point of view!
The F1 transmissions, if driven constantly at short shifting settings, are very unreliable. One can assume that improvements on calibrations and new technology (the projected electric drive support for example) will give that concept a fair share even in the future. Still it is worth to consider that it failed on a broad basis in everyday cars in Europe.
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