Haystack

I find the self-study and other audi guides to be very helpful.

Has anyone seen a link to a guide for the 7-speed S-Tronic tranny? I did a google search and poked around here and have not found anything.

Thanks in advance!

(Champing at the bit for the arrival of my new S6!)

ronbars

Try here. The 0B5 gearbox stuff starts on page 24.

wattz24

And on page 29 you see how we get that dreaded "lag" when the transmission preselects a gear and you do something to make it change it's mind. That's when it lags. Aka slowing down the car is still in a high gear and boom the red light changes green. And you "hit it" now the transmission has to jump from 5th gear to 3rd and that's when you get the big lag time. Since it's on the same "plate" you have to wait for the clutch to disengage select third and reengage. It's not taking any longer than what it would take if you are shifting yourself. But since we expect the car to drive like a automatic it seems like forever aka maybe 2 seconds or so.

nobbyv

Possible, but I don't see how that differs dramatically from a standard automatic. Or why those with S-Tronic S4s don't seem to have this issue (apparently). But I'd like to learn more, except I don't think you referenced the right page: page 29 shows the ATF filter and cooler. Can you clarify which page you mean?

goliath1

i dont know what this lag is all about. i mash the pedal and my eyes go to the back of my head. Maybe my S6 is special!!

mwar99

Mine goes from 7th to 3rd without any lag. My lag comes at rolling stops, not at speed where it would go from 5th to 3rd.

wattz24

Shifting
To drive forward, the driver shifts the selector lever into D and drives away in 1st gear. When a defined speed threshold of approx. 10 mph (15 km/h) is exceeded, 2nd gear is engaged in sub-gearbox 2 (reverse was previously engaged).
When the shift point for upshifting from 1st to 2nd gear is reached, the gearshift is made by the rapid opening of clutch K1 and simultaneous rapid closing of clutch K2 without any interruption in tractive power. To enhance shift comfort and preserve the clutch, engine torque is reduced during the gearshift (overlap).
The gear shifting process is completed within a few hundredths of a second. 3rd gear is now pre-selected in sub-gearbox 1. The process described above repeats itself alternately during the subsequent gearshifts from 2-3 up to 6-7.

Is the paragraph I was referring to.
As far as the rolling it also is the same lag as my example. Typically if you were rolling along in say third gear the car is preselected fourth and is expecting you to either accelerate slowly. And you "floor it" now the cars computers will say third and fourth are not going to cut it we need either 2nd or 1st. But none of those gears are preselected. So either way the car has to un-select the gears it's in and disengage and reengage the clutch. I've felt the same thing. But we have to remember our cars really are just fancy Manual transmission with automated clutches.

nobbyv

I understand your hypothesis. But BorgWarner quotes gear change times of 230mS. So even if the tranny had to change gears "twice", as in the scenario you outlined, that's still only half a second. The lag I experience is well in excess of that; it's about 2-3 seconds.

ronbars

Yesterday I was coasting down from about 25 mph and encountered a yield sign which I slowly rolled up to. At around 3-5 mph, I put my foot back on the gas pedal and got nothing for a solid 2-3 seconds. I must have been subconsciously giving it a little more pedal during the lag, as once the car moved forward it did so more quickly than I'd anticipated. Throughout, I felt nothing that would indicate that the transmission was trying to find the right gear. In fact I didn't feel a shift at all, and imperceptible shifts are not a hallmark of these transmissions at those low speeds.

I suspect the lag is at least partially a function of the drive by wire throttle programming. I'd like to datalog the position of the accelerator pedal versus the position of the throttle valves under these circumstances - past experience doing so (on other makes) has always proven interesting.

txgriz

I posted this in another thread too.

"The car does not down shift from 3 to 2 fast enough and rolling through a corner and then gassing it will show the problem. Easy solution I discovered on the track, manually downshift to 2 going into the turn with the left paddle (you do not have to be in manual mode to do this either). Boom, no lag out of the turn. You just have to remember to do this if you want the quick response. Careful though, you will burn through tires with all that juice coming out of the turns. "