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    The unspoken question about DSG/PDK vs. Manual

    I think the one fact that is frequently overlooked in the debate of the dual-clutch gearbox versus the manual gearbox is that Porsche is going to present the DSG/PDK gearbox with 7-gears.

    There is no indication that Porsche intends to offer a 7-speed manual, so I assume buyers will be left to choose between a 7-speed PDK or a 6-speed manual.

    I am a huge proponent of the manual gearbox, as I think it provides much greater driver involvement.

    However, I think cars like the GT3 cry out for more gear ratios. Anyone who has driven a 996 or 997 version of the GT3 on the track knows that the gears are too tall and widely spaced for optimum performance.

    This is necessary if one wants to retain the maximum speed of the GT3 (>190 mph). Adding a 7th ratio will allow a high top speed in 7th and better spacing of the remaining 6 ratios for acceleration and track performance. It will be a noticable improvement to performance (not because of the faster shifting of the dual-clutch, but because the car will be near its engine's power peak more often).

    I think this disparity will also serve as a marketing opportunity for Porsche. They will be able to show how their dual-clutch gearbox provides faster laps than the manual (with one fewer ratio), and will give customers a reason to spend the money for this expensive option.

    What do you all think?

    Re: The unspoken question about DSG/PDK vs. Manual

    With manual gearboxes, gear spacing can be an issue on some tight tracks. With 7 gears, people won't even have time to release the clutch before they have to upshift again.

    Paddle-shifting gives the driver enough time to actually use the additional gears.

    Re: The unspoken question about DSG/PDK vs. Manual

    Sounds like a reasonable theory to me. I've got to admit, as a die-hard manual rower I'll be faced with a quandary if it comes to a decision between a 6 speed manual versus a 7 speed flappy-paddle option.

    Re: The unspoken question about DSG/PDK vs. Manual

    Like you guys are saying.

    Since the shifts are perfect, extremely fast, and _effortless_ why not make it a seven speed? Will put power into road more efficiently.

    If you get tired of "too many" gears just flip to automatic mode.

    Gotta have a _performance_ edge to justify extra cost and make the choice more attractive for manual tranny diehards.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    The Groom said:
    With manual gearboxes, gear spacing can be an issue on some tight tracks. With 7 gears, people won't even have time to release the clutch before they have to upshift again.

    Paddle-shifting gives the driver enough time to actually use the additional gears.


    I disagree. On most tracks (not Nurburgring) with a GT3, you're only in 2nd, 3rd or 4th gear (some tracks you're rarely able to use 4th or not at all - car goes pretty fast in 3rd).

    With a 7spd, you'd still be in 2nd, 3rd and 4th most of the time, but the revs won't fall off as far when upshifting (better performance). It won't mean that much more shifting...

    With my 73RS replica, I have a custom gearbox with a very low and close gearset. I use 2nd, 3rd, 4th, and 5th gears on EVERY track (and barely redline in 5th on some at the end of the straight). It is not a burden - it's a pleasure

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    Grant said:
    I am a huge proponent of the manual gearbox, as I think it provides much greater driver involvement.




    On just this topic, there is now a very interesting and at times hilarious review, in Sports Car International (a not-so-well distributed but often well written mag) of the new Mitsubishi Evo X - which now offers a DSG. The author Jay Lamm echos Grant's view on DSG-style trannys, as he says:

    "But the issue with such transmissions is never the shifts themselves, it's the electronic decisions that go into making them. Being a dual-clutch design, the Getrag constantly pre-selects what it thinks the next gear will be. That helps a lot when conditions are basically normal, but if you want to do something odd-back off the gas and then ask for an upshift, say-it doesn't quite know what to do. Similarly, even in S-Sport, the most aggressive of TC-SST's three modes, it refuses to pull as screaming a downshift as you would and won't hold a gear when you back off to let someone pass."

    Review is here: http://www.sci-mag.com/art1/art1p1.html

    What this admittedly single view appears to say is that while the fast shifting of a DSG/PDK is appealing, having its brain do things you would not have done yourself is not as thrilling. Might this be a reason that Ferrari have stuck with the single clutch F1, which does not try to out-think the driver?

    Later Lamm concludes:

    "The fact is, car companies inevitably pitch semi-autos as "sporty" precisely because that's what they aren't; no matter what the selector is made of or how many F1 cars use them, street-machine paddle-shifters don't exist to enhance driving pleasure. They exist to sell cars to the ever-increasing millions who won't (or can't) deal with a clutch."

    Them sounds like fightin' words for PDK fans...

    Re: The unspoken question about DSG/PDK vs. Manual

    It would be very difficult to use 7 Gears in a manual.

    The reason why the manual transmission for the 5/6 series BMW's with 7 speed SMG is that the shift pattern would be so complex no one could use it.

    Re: The unspoken question about DSG/PDK vs. Manual

    I asked that before and I 'm clear now.

    PDK no doubt, it provides much greater driver involvement for me and most important is faster lap time.

    I hope there are PDK for the facelift, I remember everyone told me the 997 RS mk1 would have 3.8 motor and end up just the same 3.6 motor , so I wish this time the PDK is true.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    Moogle said:
    It would be very difficult to use 7 Gears in a manual.

    The reason why the manual transmission for the 5/6 series BMW's with 7 speed SMG is that the shift pattern would be so complex no one could use it.


    Tom - It wouldn't be that hard. A six speed already has 4 vertical gates. You would simply have first gear below Reverse like the dogleg racing patterns used in cars like the early 928, pre-1972 911, BMW 635CSi Euro, etc. They were like this, where you only used 1st to get moving and used 2-5th for driving and it was more convenient than a standard 5 speed:

    R 2 4

    1 3 5

    I actually like that pattern alot. Although these cars were all only 5-speeds, it could easily be done with one more gate.

    Just imagine the current Porsche 6-speed pattern:

    R 1 3 5

    X 2 4 6

    and then make it like this:

    R 2 4 6

    1 3 5 7

    If people find it too hard to adapt to the switching of odd and even gears, you could do this too:

    1 3 5 7

    2 4 6 R

    There could be electric lock-out of reverse when car was rolling, so you would never have a risk of hitting Reverse when downshifting from 7th, for instance...

    Re: The unspoken question about DSG/PDK vs. Manual

    The only way this can work is if the shifter is actually gated (like in manual Ferraris). Otherwise, it's just a Type 2 over-rev waiting to happen.

    By the way, there's a reason dog-leg patterns were discontinued: while it's more convenient on a track, it's a PITA in stop-and-go traffic. Since cars are used more often in the streets than on a track, it's no wonder they are gone.

    To put it in a nutshell, I think your solution is looking for a problem.



    I don't get why "purists" like "luddite" gearboxes so much. Rowing is just as artificial as pressing a paddle. I sure hope you're not using one of those pansy synchromeshed gearboxes.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    The Groom said:
    The only way this can work is if the shifter is actually gated (like in manual Ferraris). Otherwise, it's just a Type 2 over-rev waiting to happen.

    By the way, there's a reason dog-leg patterns were discontinued: while it's more convenient on a track, it's a PITA in stop-and-go traffic. Since cars are used more often in the streets than on a track, it's no wonder they are gone.

    To put it in a nutshell, I think your solution is looking for a problem.



    I don't get why "purists" like "luddite" gearboxes so much. Rowing is just as artificial as pressing a paddle. I sure hope you're not using one of those pansy synchromeshed gearboxes.





    Once you get used to the F1 type tranny, there is not turning back to the manual. The benefits of F1 over manual are overwhelming. Even those who feel they want more involvement i.e.shifting and depressing the clutch, will find the F1 in competitive mode can engage the driver as much if not more.

    Manual transmissions are dinosaurs and it is time to bury them.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    nberry said:Once you get used to the F1 type tranny, there is not turning back to the manual.


    Nick - I have driven Ferraris with both F1 and manual gearboxes and I far prefer the manual, as do most of the knowledgable European journalists who have tried both.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    The Groom said:I sure hope you're not using one of those pansy synchromeshed gearboxes.


    Groom - I'd be more than happy to use a racing "Crash" gearbox without synchromesh, but I couln't afford it

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    The Groom said:
    To put it in a nutshell, I think your solution is looking for a problem.




    I'm afraid too many people would have difficulties with a four-lane shift pattern. I do know enough people who had to get used to a 6th gear already, using a "three lane" pattern leaves you with only three consecutive choices: keeping the lever in middle position, placing them left or right before performing the shift. The auxiliary lane used in reverse is usually disengaged by shifting resistance or mechanical lock. Unless you utilize something like this on a 7-speed box people will stay away from it.

    I agree that the additional gear will be further advantage for the DSG system, additionally performance-orientated engines as in the GT3 (with torque and power maximum at very high RPM) will benefit even further.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    Grant said:
    Quote:
    nberry said:Once you get used to the F1 type tranny, there is not turning back to the manual.


    Nick - I have driven Ferraris with both F1 and manual gearboxes and I far prefer the manual, as do most of the knowledgable European journalists who have tried both.



    Admittedly Ferrari's system has significantly improved over the years, however a self-shifting gearbox will always improve a driver with lesser shifting and driving skills, the performance difference might diminish the better the driver is!

    Re: The unspoken question about DSG/PDK vs. Manual

    Grant thank you for highlighting the possible shift patterns, however, due to gear configurations, a simple, intuitive layout like the ones you mentioned are not possible. That is what I meant originally.

    You would wind up with something like

    R 3 5 2 6

    X 1 7 4

    Something like this was published in an article (British CAR magazine, circa 2006) about why it was difficult for them to make the 7speed SMG a manual when the 5/6 series first came out, the layout of the gears would make the resulting shift pattern terribly confusing.

    That is why despite 7speed SMG/F1 style transmissions, the manual is still a 6 speed.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    Moogle said:
    Grant thank you for highlighting the possible shift patterns, however, due to gear configurations, a simple, intuitive layout like the ones you mentioned are not possible. That is what I meant originally.

    You would wind up with something like

    R 3 5 2 6

    X 1 7 4

    Something like this was published in an article (British CAR magazine, circa 2006) about why it was difficult for them to make the 7speed SMG a manual when the 5/6 series first came out, the layout of the gears would make the resulting shift pattern terribly confusing.

    That is why despite 7speed SMG/F1 style transmissions, the manual is still a 6 speed.


    Tom - yes, I remember reading that too, but I don't buy it. I think the jumbled shift pattern is only a result of trying to modify an existing 6-speed or 7-speed SMG box.

    But, I really think there is no reasonble explanation that a freshly designed 7-speed manual box couldn't be made to have a logical shift pattern. Why would it be possible with a 4-speed, 5-speed, and 6-speed, but totally impossible for a 7-speed?

    I may be a bit cynical, but I believe BMW gave that bogus explanation as a reason not to pursue it, since it can't charge extra for a manual box and it wanted to steer people towards the more profitable SMG box.

    Converting the SMG 7-speed to a manual might be difficult, but there is no way it's impossible to build a fresh 7-speed with a logically arranged double-H pattern.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    nberry said:
    Quote:
    Once you get used to the F1 type tranny, there is not turning back to the manual.



    Of the friends who own Ferrari's they all owned cars with F1 transmission and within a year sold them and replaced them with proper manual stick shift 430's. The argument was crappy electronics and hydraulics that kept failing, but much more importantly a significant loss of involvement.

    They're now happily back driving sports cars rather than red PlayStation consoles.

    Re: The unspoken question about DSG/PDK vs. Manual

    It's funny you mention PlayStation consoles. I grew up playing racing games. Paddle shifters feel much more natural to me.

    I'll grant you that most F1-type transmissions suck. They're too unreliable and jerky. Yet, there is no reason that cannot be fixed in the near future. I've heard nothing but praise about the 599's F1 gearbox.

    Porsche has chosen to wait until the tech was ready for prime time. I expect not to be disappointed.

    Re: The unspoken question about DSG/PDK vs. Manual

    I think it's also a matter of how the software is implemented. I've driven 2 F1 gearbox style cars, 575M and E46M3. Both of these are pretty much a manual gearbox with the only diffenece being they don't have a clutch pedal. But you still have to shift with the paddle, the computer will not do it for you. The only exceptions are (a) you are in Auto mode, or (b) you are about to lug the engine. In those cases the computer will perform a shift (E46 will downshift in case (b) for sure, can't recall if the 575 does this also). Otherwise you are in complete control of which gear you are in and the shift speed is pretty much instant (ie. faster than 99% of drivers could do in a pure manual gearbox).

    I have also driven 1 DSG car, a Mk5 GTI. That was a whole different story. Even if you are in Manual mode, the computer sometimes still shifts on its own on both up and down shifts. Much less control for the driver. But due to the dual clutch system, the upshifts are very smooth indeed.

    Personally I prefer the software of the F and BMW over the VW. Hopefully Porsche will lean more towards the manual side when they implement the software in their PDK. It would be really nice if they offered some config options via the PCM to allow a driver to tailor the PDK software behavior to suit their tastes.

    One aspect of both systems (ie. F1 style and DSG) is that unelss there is a malfunction, downshift induced over-revs are no longer possible. The computer will refuse to downshift if your revs are too high for the pre-selected lower gear. I think even the most die hard supporters of the "clutch pedal forever" position would agree that can only be a good thing.

    Another interesting detail is the choice of where to mount the paddles. 575 mounts to the steering column whereas BMW & VW mount to the steering wheel. FWIW, I believe all F1 race cars use the latter but then their wheels have much less rotation than a road car.

    Re: The unspoken question about DSG/PDK vs. Manual

    I would tend to agree. for spirited mountain road driving, I only use 2-3-4...so more gears would be nice...But I love shifting so much that this ain't gonna happen :-)

    Re: The unspoken question about DSG/PDK vs. Manual

    Hi Grant!

    Great discussion topic on PDK/DSG! I would certainly agree that the "performance advantage" of PDK is likely to be primarily from closer ratios with a 7-speed gearbox, with a smaller gain from reduced shift times...

    Apparently, the new Nissan GT-R 6-speed dual-clutch transmission has a shift time of 0.2sec, which might sound slow compared to the Scuderia's 0.06sec... but it's also worth noting that the Borg Warner clutch pack is designed for a 155,000-mile life, compared to a Ferrari's 6,000-8,000 miles before the F1 gearbox needs a new clutch!

    "The six-speed GR6 transaxle was developed especially for the GT-R, partly because it's hooked up to a high-revving engine."

    "Developed partly by Borg Warner, which supplied the very compact clutch pack (designed for a 155,000-mile life), synchromesh and electronic control unit, each transmission is built by a single engineer working in a 'clean room'. The electronic traction control and limited-slip diff are integrated into the transmission casing."

    ...reportedly, there was a quote from Porsche that the PDK gearbox will help take the 911's performance to the next level!

    Cheers!


    Porsche PDK gearbox with clutch pedal...

    Porsche PDK gearbox with clutch pedal...

    The Porsche RS spyder sequential gearbox includes a manual clutch pedal which can be used for low speed manoeuvres...

    ...so maybe including a clutch pedal with a PDK dual-clutch gearbox would provide the perfect solution - allowing the potential for both sequential gear changing and manual gear changing at your option!

    While a racing sequential gearbox may not be an appropriate street solution - given cost, longevity, noise, etc - adding a manual clutch pedal to a DSG/PDK style gearbox could be a potentially interesting solution...

    If you're used to a manual gearbox, driving a semi-auto (SMG, F1, etc.) or dual-clutch (DSG) can seem a bit cumbersome for low speed manoeuvres... like playing the piano with your elbows!?

    Some manufacturers have built in some degree of creep into their semi-auto transmission, but many seem to end up cooking their clutches during low speed driving or parking, with the clutch trying to mediate the battle between the accelerator and the brakes...

    So given the option to also have an additional manual clutch pedal - which should be possible to engineer, given the RS spyder transmission - this could lengthen the life expectancy of the clutch and provide that additional subtlety you get with a manual transmission!

    ...and sometimes it's just great to be able to blip the throttle!

    Overall, a good manual still seems like the best solution - but wouldn't mind having the option of a sequential-style change for the occassional track day!


    Interesting!

    I wonder how many of the PDK enthusiasts would buy that option if they had to use a clutch pedal?

    Re: Porsche PDK gearbox with clutch pedal...

    Quote:
    Boxster Coupe GTS said:
    Porsche PDK gearbox with clutch pedal...

    The Porsche RS spyder sequential gearbox includes a manual clutch pedal [. ..[



    The RS Spyder box is a totally different system.

    I agree that a number of drivers, being fooled by the DSG's interface, might mistake it with an automatic gearbox incorporating a frictionless torque converter.

    It took ages to hone the DSG's layout & the dual-clutch element is the main feature of this system. An add., even auxiliary clutch pedal would, in my eyes, would dillute the concept.

    Re: The unspoken question about DSG/PDK vs. Manual

    Quote:
    Grant said:
    Quote:
    Moogle said:
    Grant thank you for highlighting the possible shift patterns, however, due to gear configurations, a simple, intuitive layout like the ones you mentioned are not possible. That is what I meant originally.

    You would wind up with something like

    R 3 5 2 6

    X 1 7 4

    Something like this was published in an article (British CAR magazine, circa 2006) about why it was difficult for them to make the 7speed SMG a manual when the 5/6 series first came out, the layout of the gears would make the resulting shift pattern terribly confusing.

    That is why despite 7speed SMG/F1 style transmissions, the manual is still a 6 speed.


    Tom - yes, I remember reading that too, but I don't buy it. I think the jumbled shift pattern is only a result of trying to modify an existing 6-speed or 7-speed SMG box.

    But, I really think there is no reasonble explanation that a freshly designed 7-speed manual box couldn't be made to have a logical shift pattern. Why would it be possible with a 4-speed, 5-speed, and 6-speed, but totally impossible for a 7-speed?

    I may be a bit cynical, but I believe BMW gave that bogus explanation as a reason not to pursue it, since it can't charge extra for a manual box and it wanted to steer people towards the more profitable SMG box.

    Converting the SMG 7-speed to a manual might be difficult, but there is no way it's impossible to build a fresh 7-speed with a logically arranged double-H pattern.



    Fair enough. In the end it was probably because of original packaging that the gear layout was modified on the original 7 speed SMGs...

    Re: Porsche PDK gearbox with clutch pedal...

    Quote:
    Ferdie said:
    Quote:
    Boxster Coupe GTS said:
    The Porsche RS spyder sequential gearbox includes a manual clutch pedal [. ..[


    It took ages to hone the DSG's layout & the dual-clutch element is the main feature of this system. An add., even auxiliary clutch pedal would, in my eyes, would dillute the concept.


    I remember an interview with W. Röhrl about PDK - he insisted on having a clutch pedal for low-speed and emergency manoeuvers. Maybe the production version will have one, too.

    That said, I wouldn't be surprised if the Boxster version was just a rebranded, slightly tweaked Audi DSG...

    Re: Porsche PDK gearbox with clutch pedal...

    what bothers me about pdk is the sound it makes when on you are on a high gear with very low rpm, then you slightly press the pedal.....you hear crunching of gears together or more of a gear rattle. you have to give an ear out, but it is there

    how can this be acceptable on a new technology . 


    --

    MY09 C2S Atlas Grey, PDK, LSD, spacers, PSE

    MY07 C2S Meteor Grey (Sold)


    Re: Porsche PDK gearbox with clutch pedal...

    I'm surprised nobody has mentioned sequential shifting.  I'm sure many of you have tried to shift down from fourth to third at high speed only to discover "it won't go".  I guess the little blocking plate in the shifter has moved such that you're really trying to get into first.  It's scary when you have a turn up ahead, you need to get ready for it fast, and the thing won't shift.  That's when I'd like a sequential shifter.  There's no way I can inadvertently try to get into first.

    Has anybody put the sequential shifter kit on their manual transmission?  How do you like it?


    --

    2008 GT3

     


     
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