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zeroshift gearbox

Discussion in 'Ferrari Discussion (not model specific)' started by ferrari_kid, Jan 19, 2004.

  1. ferrari_kid

    ferrari_kid Formula Junior

    Jul 5, 2003
    768
    i was reading the new racecar engineering mag and there was an article about a revolutionary new gearbox that can shift between gears without a noticeable change in power. it works by selecting two gears at once and doesn't use a clutch. when i mentioned it else where there were comparisons to subarus CVT or lawn mowers, but this is well beyond that. the author even predicted that within 10 years all cars will be built with this transmission because it's so cheap and efficient. anyone else read the article?
     
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  3. noony

    noony F1 Veteran

    Nov 25, 2003
    5,903
    Seoul
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    Johnathan
    DSG right?
     
  4. 96impalaSS

    96impalaSS F1 Rookie

    Dec 8, 2003
    3,504
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    Chris
    ive read about how Mercedes is making a 7 speed automatic transmission that goes from like 7th gear straight to like 4th without going through the gears.It just goes to whatever gear you need when you brake into the turn and then start accelerating out.Aweasome idea.
     
  5. PSk

    PSk F1 World Champ

    Nov 20, 2002
    17,673
    Tauranga, NZ
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    Pete
    Audi have developed and are now producing cars with a double clutch gearbox that does select 2 gears at once, ie. the one that is being used and then the one it thinks you are going to use next. Thus when you say to the computer that you want that next gear it just has to let the clutch out (I believe) ... thus extremely fast gear changes.

    The only negative is 2 clutches but clutches are pretty well sorted nowadays and also if you do not select the gear the 'brain' thinks next it takes a while to sort that out.

    Pretty clever stuff, but I have not heard of what you are talking about ... while have to keep a look out for the mag.

    Pete
     
  6. ze_shark

    ze_shark Formula 3

    Jul 13, 2003
    1,273
    Switzerland (NW)
    I drove an Audi A3 3.2 with the DSG box today, it's really bluffing. This gearbox is really well sorted out, never seen faster and cleaner shifts. Way beyond any sequential gearbox I got to try, M3 SMG2 or 355/360/575.
    If you don't listen to the engine, the only way to notice a gear change (up or down) is to witness the sudden rpm needle movement. No perceivable torque interruption, this is no mkg spin.
    No torque converter, perfectly smooth, superbly fast.

    Paddles allow to override at any time, but the auto mode does a pretty good job. Slow speed parking movements are easy (surprisingly the car moves on its own at idle like a real auto, don't know how they achieve this without wearing the clutch out), and power starts are very well managed, no excessive clutch slippage.

    Aside from the extremely over-assisted brakes, the car is really damn good for real life use. I would really consider eventually trading my S4 for an A4 3.2 DSG once there will be one.

    The only downside is that it's perfectly boring to drive. Perhaps a good fit for the Gallardo ? >:)
     
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  8. ze_shark

    ze_shark Formula 3

    Jul 13, 2003
    1,273
    Switzerland (NW)
    Further read on the topic that Porsche plans this as an option on the 997. Between the much improved esthetics, increased power (350hp in base version) and the DSG box, this could become a rather good every day car.
     
  9. robinh

    robinh Formula Junior

    Jan 3, 2004
    622
    Cambridgeshire, Engl
    Full Name:
    Robin
    Ok, the next generation of fighre aircraft are predicted to build without a seat for a pilot as the computer can do everything and people can't fly to the limits a plane can without dying.

    Cars it seems are going the same way, get in, it will sense who is in, adjust the seats, start the engine, ask you where you want to go and get there while you sleep - yawn, yawn, yawn.
     
  10. Victory

    Victory Formula Junior

    Jan 28, 2004
    410
    Something to look forward to, if Ferrari adopts this system as well.
     
  11. Bart

    Bart Formula 3

    Nov 1, 2003
    1,488
    Orange County, Calif
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    Bart
    Robinh,
    You are right. Just start the car, press the buttons into the nav system and away you go. Boring.
     
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  13. wazza

    wazza Formula Junior

    Oct 9, 2003
    614
    Correct me if I'm wrong, but isn't it the same type of gearbox and clutch setup that is used in Formula 1 now. ( ie, no driver imput needed)
    or is that something different.

    Wazza
     
  14. ferrari_kid

    ferrari_kid Formula Junior

    Jul 5, 2003
    768
    exactly the system i was talking about. the article in race car engineering went into a little bit more detail about how it worked yet didn't cover exactly what it was. i couldn't find any other sources that had information about the zeroshift system until this one, thanks.
     
  15. ferrari_kid

    ferrari_kid Formula Junior

    Jul 5, 2003
    768
    no, from what i read F1 hasn't even picked up on the system yet. it would be ideal for them but even their gear boxes have a point in time where they lose power (in transition between gears). it's being tested on GT class cars in the UK, specifically the TVR. i'm sure we'll see it in F1 soon though.
     
  16. ze_shark

    ze_shark Formula 3

    Jul 13, 2003
    1,273
    Switzerland (NW)
    I am skeptical that this will ever make it to F1, already would have long before VW/Audi was able to bring DSG to mass production if it made technical sense.
    I would not speculate on the actual benefit in terms of torque interruption time, the DSG system still implies a transition of torque between one clutch and the other, and F1 shifts are very fast.
    The main reason however why I would not see this making it to F1 is size (volume). F1 teams have constantly struggled to make hyper small and light gearboxes (with magnesium or even carbon housings), with huge reliability implications, for the sake of clearing the way for aerodynamics.

    Would be interesting to know who holds the patents for the double-clutch system.
     
  17. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,054
    It is a revolutionalry idea that is very simply.

    Simply replace the dogs on the gear and selector shafts with a rotational double catch**. When the gear shift is moved from one gear to the next, the old gear remains engaged. When the new gear is selected, a bind between the old gear and the new gear causes the double catch to release* on the that gear which is not being held by the gear select lever. A small spring and detent ball holds the gear when less than maximum power is desired. Thus it is the bind that occurs when two different ratios are selected that 'causes' one of the gears (the non-selected one) to disengage.

    I don't know if the double catch can be made strong enough for F1 applications at the current packaging size of F1 gears and synchros. But this seems like the kind of technology that would be worth a few pounds.

    As to completely taking over shifting activities, I don't know. I shift without a clutch all the time on my motorcycles and get very quick shifts. And although I roll off and on the throttle to smooth the transition, the clutch pack still takes a regular beating from this treatment.

    *I think both double catches actually disengage, but the one being held in place get to relatch after the binding moment.

    **I don't know if the real name of the dog replacement is called a double catch.
     
  18. ZeroShift

    ZeroShift Rookie

    Apr 1, 2004
    3
    Milton Keynes, UK
    Full Name:
    Phil James
    Thought I'd drop by to say Hi.

    F1 shifts are generally about 50ms, US open wheel cars about 70-80ms. Audi claim (or at least the press prints) 20ms for the DSG shift but you'll also read 200ms/0.2secs in some media. Whatever the time is, it's the 'kiss period' during which the two clutches fight one another i.e. one is taking up drive in sync with one letting go - it could well be as little as 20ms (i.e. 'faster than F1') but that's not the whole story. The actual time of a DSG shift involves the moving of two selectors and sync'ing of two clutch movements. If you do one shift, it feels really quick. Try doing two in a hurry e.g. 5-4-3 to overtake a truck and uncover how slow the shifts are as the gearbox goes through 4th en route to 3rd. An F1 shift of c.50ms is a complete shift - it's fast!

    Given the 'speed' of the DSG shift, you'd be led to believe that it's a performance advantage, right? Against an auto it is. Against a manual it's not. Check out Autocar stats comparing Audi A3 manual and DSG. The DSG car is slower to 60; has worse fuel economy/emissions, costs more and weighs more. DSG is not a sports box - it's a very good manumatic. It is however the only transmission type that can match ZeroShift's linear longitudinal 'g' - a function of uninterrupted torque to the driven wheels. Like all new transmissions, DSG benchmarks its advantages against autos. DSG is too heavy for F1 although it has been tried (as was CVT by Williams).

    Only ZeroShift benchmarks improvements against manuals and, by extension, all other transmission types including F1 sequentials.

    Here's the simple benefit of uninterrupted torque: inter-gear traction control. Easier on the driveline (no snatch to joints and bushes), enables mid-corner shifts etc..

    With reference to size, we've made a ZeroShift mechanism to fit in an F1 box and we can ZeroShift bikes too. Size (volume, weight) is one of our key advantages.

    Just because things haven't been done before doesn't mean they can't be done. That's the essence of inventing! :)

    Mitch Alsup has a good example of how zero-shifting can work but also outlines some of the problems.
     
  19. ferrari_kid

    ferrari_kid Formula Junior

    Jul 5, 2003
    768
    R&T tested an Audi TT with DSG vs a Z4 with SMG. The SMG beat the DSG to 60 by half a second. Normally the TT gets to 60 in 6.7 sec, with the DSG it gets there in 6.3. It really isn't much quicker. I can't wait to see some test times with the Zeroshift on some of these cars.

    It seems as if Audi's system doesn't do much other than keep uninterupted torque to the wheels. Even with the SMGs engagement and disengagement of the clutch it's still quicker than the Audi.
     
  20. tvrfreak

    tvrfreak F1 Rookie
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    Mar 31, 2003
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    A TVR Griffith assisted in the early days of the McLaren F1's development.
    A TVR Cerbera assisted in the early stages of the Mercedes-McLaren SLR's development.
    TVR's Speed 8 set records when it was introduced.
    TVR's Speed 12 broke new ground as well.
    TVR's Speed 6 continues to break new ground.
    The TVR Tuscan has set numerous records.
    The TVR T350 has set a record at the Nurburgring.
    The TVR Typon and T440 both used a special Carbon-Kevlar composite as integral parts of a chassis for the first time.
    TVRs regularly feature in the top 10, top 20, and top 50 choices of drivers' picks in top motoring mags.
    TVR is seriously committed to racing.

    And here we have TVR helping to advance automotive technology again.

    Hopefully they will come stateside soon. These cars just make me proud.

    Go TVR!
    :)
     
  21. tvrfreak

    tvrfreak F1 Rookie
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    Mar 31, 2003
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    I don't think this technology will take away from the driving experience. A decrease in the car's "lurching" between shifts is a good thing--an uninterrupted flow of torque results in acceleration gains, and enhances driving pleasure.

    I drove an Aston Martin Vanquish for sixty-odd miles (at least 20 of them uphill) last Friday, and it's only let-down was the extended time required for upshifts. That car is a primary candidate for this technology.
     
  22. ZeroShift

    ZeroShift Rookie

    Apr 1, 2004
    3
    Milton Keynes, UK
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    Phil James
    We're using the Cerbera as a test rig independent of TVR - it's my own car! It's the same principle as McLaren using a TVR as a mule really.

    I am a fully paid-up TVR nut - I've raced in the Tuscan Challenge and currently have a Red Rose Tuscan Speed Six as well as the Cerbera 4.5 that the ZeroShift workshop has 'kidnapped' for testing.

    The Cerbera is damned quick anyway but with the ZeroShift box it's extraordinary as it just piles on the mph - I reckon we'll get close to the McLaren F1's 0-100 time with it when we measure it. You're right, it does add to the driving experience, ZeroShifting feels/sounds like nothing you've heard before - the acceleration kicks you in the guts then holds you in the seat. The engine note just changes on each shift. Fantastic! :D

    Imagine doing it to a Vanquish! We'll be able to before long because the Vanquish uses a T56 box (one of the first boxes we're modifying). I think it will transform the car. We'd like to take a look at the 355/360 Ferraris with F1 kit, Maserati GT/Quattroporte with Cambiocorsa and BMW SMG. Our internals with their automation hardware using our FlatLiner technology will reveal how fabulous these cars are behind those clunky paddle boxes. :D
     
  23. ferrari_kid

    ferrari_kid Formula Junior

    Jul 5, 2003
    768
    We were talking about the F1's 0-100 times in another thread. McLaren says they get to 100 in 6.3 sec, Road and Track tested an F1 at 7.6 sec. What kind of 0-100 times do you expect in the TVR with the zeroshift tranny? That's pretty amazing if you can close in on that kind of time with a power to weight ratio that isn't very compareable. All that really says is that one of these cars, like an Enzo or F1, with zeroshift would be that much quicker.
     
  24. ZeroShift

    ZeroShift Rookie

    Apr 1, 2004
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    Milton Keynes, UK
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    Phil James
    To estimate the gain for ZeroShifting, decide how quick you think you shift now and subtract that from every gearchange between 0 and X mph. (Or your best lap time...)

    The 4.5 Cerbera has been variously timed between 8 and 9 seconds for the 0-100 dash. I understand on a particularly sweet run that one road-tester did a 7.9.

    The F1 only has one shift between 0 and 100 (it gets past 60 without shifting). The Cerbera has two shifts. Assuming you take 0.5 - 0.75 seconds out for each gearshift, that's up to 1.5 seconds off the TVR time. Bear in mind 0.5-0.75 is pretty quick shifting - most people are slower than this, especially for the cross-gate 2 to 3 shift. Travel-across-the-gate time makes no difference to ZeroShift - the ratio swap is still instant as 3rd overdrives 2nd, all the time you're moving the stick from 2nd, you're still in 2nd. (To get neutral you move the stick to neutral and lift off the gas.)

    You'd only get one shift advantage in a ZeroShift McLaren so the gain would be less (although you'd add up the gains on the way to 241mph...). Something else interesting is happening here... because there's no time penalty on shifts, there's more scope to play with the ratios or to even add ratios. Low 1st's and 7-speed transmissions would be logical.
     

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