Question for S8 Gurus
03-21-2012, 11:16 AM
#2
AudiWorld Member
You mean to "cure" the problem with the bigger engines mated with this transmission, that it acts quite harsh when you give the accelerator pedal a too quick punch from standstill?
I learned to live with the thing after a couple months, after going from a 1998 Volvo S90 4speed auto to this.
The thing is that this ZF 6HP26 transmission, as many other newer transmissions lock up the torque converter under heavy acceleration (20-30% or more throttle), and this creates a similar effect as dropping the clutch on a manual car (as the TC acts as a clutch).
This is especially apparent with 4L and bigger engines, as they are so powerful even in the low rev area, that they can "punch" the car forward.
My friend who has driven almost every A8/S8, Q7:s and so on with this transmission reported that this problem is especially apparent with bigger engines, especially the S8 5,2L V10 and the W12. Not such a biggie with TDI engines and V6/V8 as they don't have the huge power in the low rev area.
I'd also be interested in a cure for this problem. A start in 2:nd or 3:rd gear would be a solution that the engine can handle, but i don't know if the transmission likes it. Sould be able to code it so it starts in these gears only at low throttle and D mode. S-mode always start with 1st gear.
I learned to live with the thing after a couple months, after going from a 1998 Volvo S90 4speed auto to this.
The thing is that this ZF 6HP26 transmission, as many other newer transmissions lock up the torque converter under heavy acceleration (20-30% or more throttle), and this creates a similar effect as dropping the clutch on a manual car (as the TC acts as a clutch).
This is especially apparent with 4L and bigger engines, as they are so powerful even in the low rev area, that they can "punch" the car forward.
My friend who has driven almost every A8/S8, Q7:s and so on with this transmission reported that this problem is especially apparent with bigger engines, especially the S8 5,2L V10 and the W12. Not such a biggie with TDI engines and V6/V8 as they don't have the huge power in the low rev area.
I'd also be interested in a cure for this problem. A start in 2:nd or 3:rd gear would be a solution that the engine can handle, but i don't know if the transmission likes it. Sould be able to code it so it starts in these gears only at low throttle and D mode. S-mode always start with 1st gear.
03-21-2012, 12:28 PM
#3
AudiWorld Super User
Not sure I see it this way
To the OP, I don’t think there is a way to re code the transmission to do what you want.
I guess my view is different: I think Audi (and other manufacturers) intentionally code the pedal feel this way to make the car feel “powerful.” The term I am familiar with to describe it is “tip in.” Relates to how linear (or non linear) the throttle opening is vs. the gas pedal position. If the manufacturer sets it up to drive a lot of throttle movement from modest initial pedal movement, it can give you a feeling of lots of power. Good for test drives I guess.
It’s better (less touchy) on my D3 W12 than on my C5 4.2, though I’m crossing both engines and platforms there. Having driven a Jag Xj 4.2 with the 6 HP 26, it’s almost ridiculously bad/overly sensitive just off idle, to wear you can easily scratch the tires with modest throttle movement. I know from my MINI, it can ultimately typically be programmed; that car is known as having a difficult throttle feel, particularly with a stick. The leading aftermarket tuner for second (current) gen MINI’s offers different flavors of canned choices that are sorted by linearity of throttle feel. On the D3, just not that kind of aftermarket support w/ small owner base.
Nonetheless, one suggestion: run the adaptation for the throttle. Don’t know, recall process on D3, but remember it on my 4.2 C5. It may have “learned” some bad habits over time, so a basic “reset” via adaptation may help.
I guess my view is different: I think Audi (and other manufacturers) intentionally code the pedal feel this way to make the car feel “powerful.” The term I am familiar with to describe it is “tip in.” Relates to how linear (or non linear) the throttle opening is vs. the gas pedal position. If the manufacturer sets it up to drive a lot of throttle movement from modest initial pedal movement, it can give you a feeling of lots of power. Good for test drives I guess.
It’s better (less touchy) on my D3 W12 than on my C5 4.2, though I’m crossing both engines and platforms there. Having driven a Jag Xj 4.2 with the 6 HP 26, it’s almost ridiculously bad/overly sensitive just off idle, to wear you can easily scratch the tires with modest throttle movement. I know from my MINI, it can ultimately typically be programmed; that car is known as having a difficult throttle feel, particularly with a stick. The leading aftermarket tuner for second (current) gen MINI’s offers different flavors of canned choices that are sorted by linearity of throttle feel. On the D3, just not that kind of aftermarket support w/ small owner base.
Nonetheless, one suggestion: run the adaptation for the throttle. Don’t know, recall process on D3, but remember it on my 4.2 C5. It may have “learned” some bad habits over time, so a basic “reset” via adaptation may help.
Last edited by MP4.2+6.0; 03-21-2012 at 01:34 PM.
03-21-2012, 01:05 PM
#4
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Very nice and smooth take off from 2nd gear when you keep it slightly rolling. No question when you do Jack Rabbit start, but i between...
Sometimes I feel like I didn't properely catch a clutch and my left foot instictively starts mooving. ;-)
Sometimes I feel like I didn't properely catch a clutch and my left foot instictively starts mooving. ;-)
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