Gary Knox

Hmmm - whadda' you think?

https://www.hagerty.com/media/mainte...e929c5764f483d

Zirconocene

I know some (many) people hate them but I quite like the SMG (that's BMWese for "semi manual gearbox", but in German) in my daily driver. For the SMG (and the Ferrari F1 transmission, as I understand it from YouTube videos) it is still a hydraulically actuated system, but computer controlled. It sounds to me like Ford's idea is to completely replace the hydraulic bits with small motors or solenoids (?, I dunno, I didn't actually read the patent) which seems pretty similar in scope to the BMW and Ferrari transmissions.

The SMG transmission is not the best in city driving but at even reasonable chat it does what it needs to marvelously and remains engaging in manual mode. Closer to full chat, where the car was designed to be driven (not by me, let's not pretend) it's nearly flawless.

I dig it.

Cheers

voskian

Interesting…I have a 2004 Audi TT with a DSG ( direct shift gear) trans that runs either auto or manual mode. The wet clutch is essentially engaged and disengaged when you apply the brake which acts as the “ clutch in/out switch” . Shifts are very fast and smooth. Very similar to Porsche PDK trans.

928cs

Modern version of the Sportomatic, or Ruf's EZK?

I don't really see the point.

Zirconocene

@voskian : I think that you must have the Audi version of the PDK (DSG = (I think) DoppelShalt Getriebe, or double clutch transmission). Everyone seems to have come up with their own name for them. BMW's is called a DCT. I don't know what the Italians call theirs, but it seems that most companies have landed on "DCT".

ETA: I know we had a thread a while ago on the ZF 8 speed but I would also take a modern PDK/DCT as a replacement for my auto. Seems like a delicious upgrade.

Cheers

Petza914

I think it actually stands for "Sequential Manual Gearbox" since you have to go through the gears in order.

honerboys

back in 1969 my parents bought a new vw bug - my mom could not drive a manual and vw offered what was known as an auto stick shift - no clutch pedal but when you moved the stick on the floor it would make an electrical connection which would hydraulically operate a clutch and disconnect the engine from transaxle - ford's shifter sounds very similar - only 3 forward speeds in the vw - vw didn't offer it for very long - that car is probably a collectors item now

928cs

It was called a Sportomatic by Porsche, and Autostick by VW.

sendarius

The Ferrari F1 style gearbox, with a computer controlling both the clutch and selector solenoids has made its way down the food chain into the lowly Fiat 500, and it's awful.

My daughter wanted one ('cause it's cute), so we took a test drive in a new one. The gear changing is SLOOOOOW, and the computer controlling the shifts is stupid.
Taking off from a stop is a matter of release the brake, press the throttle, and WAIT for what feels like ages. It is probably only seconds, but it was always long enough for the driver behind to become annoyed.

Then the damn thing would change gears at all the wrong times (like in the middle of a low speed turn) and take what seemed like forever to do so. Being halfway through a turn with no power available is NOT a nice feeling.

Once I checked and discovered that the selector solenoid is quite unreliable, and costs AUD$7000 plus installation, the search for something else started in earnest.

The Forgotten On

I have a DSG in my A3 TDI. It works alright in manual mode. Shifts are quick and it responds well to the flappy paddles. But put it in auto and it does some truly stupid things occasionally.

Step on it from a stop and it doesn't seem to want to move for like half a second of lightly engaging its clutches and then it finally takes off. It loves to spin tires doing this with like half throttle.

It also takes what feels like ages to downshift to a lower gear on its own when deciding through throttle input. It makes left turns in intersections... interesting to say the least because it cuts all power from the engine.

At least it is programmed to hold gears during corners and the hill hold and hill descent features are useful. But being a 2012 it has an early DSG, the DSG in the 2019 A7 loaner I had was fantastic in comparison. Smooth and quick even in traffic.

It would be fun to have a modern quick shifting DSG or auto in a 928 with at least 6 forward gears. It would make it much more fun around town!

Petza914

Not sure why. I get in current auto rental cars with 8 speeds and it seems like they're always shifting. With a good motor, I prefer fewer gears and to hold them longer. You only use about 3-4 gears out of 6 in a MT (not a 928) and only 3 out of 4 in a 928 auto around town. You can adjust the Bowden cable and install the shifter button kickdown relay to have more control of the shifting. I prefer manuals but am enjoying my 84 928 S with 4.7L motor that has the 4 speed auto with kickdown trigger.

Darklands

Darklands

Adk46

My wife's SmartCar has an electrically/hydrauilically (not sure which) operated manual gearbox. I suppose the theme of these must be either 1) do it quick, so only one jerk, or 2) do it leisurely, though this leads to two jerks (clutch disengaged - pause - clutch engaged). The leisurely approach in the Smartcar is unsettling, the jerks coming at a time that's unpredictable to both the driver and the passenger. The single (aggressive?) jerk approach might also be overly jarring in casual driving.

I think this is what justifies the added complexity of dual-clutch gearboxes - the reduction of either form of 'jerk'. Even then, some new to DCT/DCG/PDK may complain about how they are relatively jerky compared to a proper slush box. This had to be explained to the PO of the PDK Cayman I once owned, according to the service records.

I wish our 928 slush boxes were electronic and programmable, like the '96 Caprice "SS" I briefly owned last year. The PO had programmed it to downshift very readily. I don't suppose it's possible to McGiver such a thing onto them....

===============

The terminology **** in me must point out that "dual-clutch gearbox" is wrong: it's really "dual-gearbox", since each clutch is coupled to an independent set of gears. In diagrams, it's difficult to see the two clutches since they are co-axial, but the two sets of gears are easily seen (when colored red and green as above).

puyi

Not DKG (:-) nor sportomatic.

It seems to be as tell by zirc.... replacement of hydraulic part of similarly smg style clutch by electric command. It seems that the "auto" mod may not be available, so the trans is really manual but with automatic clutch