Intermittent Severe Throttle hesitation (not turbo lag)
10-09-2018, 05:28 PM
#11
AudiWorld Member
There are also a few types of lag/delays that generally get conflated together. If you bring the A4 into the mix then we have to talk about the dual clutch transmission. In particular your scenario of slowing down and then changing your mind and accelerating again. Dual clutch transmissions work on the principal that they are two transmissions and the currently idle transmission waits in the wings with the next gear pre-selected. But this strategy relies on the transmission to be able to predict what the next gear will be. If you do something that invalidates that prediction like speeding up suddenly again instead of coming to a stop the transmission has to reshuffle and there are also protection schemes kicking in. It might have already de-clutched to prepare for a full stop, but then suddenly it needs to re-engage the clutch. Or you are cruising on the highway in 7th gear and it has pre-selected 6th on the other shaft assuming that you'll eventually slow down, but suddenly you require full acceleration and instead it has to downshift several gears. This all leads to hesitations, lags and delays, especially if the next gear is on the same shaft. One shaft has the even gears and the other one the odd gears, so for example a sudden required downshift from 7th to 3rd will cause quite a delay as it first has to release the clutch and then change the gear on the current shaft.
I do experience the same throttle lag the OP references. That specific form of hesitation seems to be common amongst the different auto tansmissions.
10-10-2018, 05:56 AM
#12
AudiWorld Junior Member
Thread Starter
As everyone else is saying in this thread, the throttle hesitation is "normal" for these cars. I have an A4 Allroad and notice it mostly in D and still feel it in S. And very little in M but then again I tend to try it harder in S or M. It also bad for me when slowing down then having to hit the gas again. Like when your approaching a red light and then it turns green. I tend to account for these delays now and lightly touch the gas until I feel it catch after the hesitation then press the pedal down harder.
There is this thread over in A4 B9 forum on throttle lag you may find interesting to read. This specific post refers to a trick that supposedly reset the throttle map. I don't think this would elimate the hesitation but if you reset it and maybe drove it a particular way you, maybe could get it to feel better.
https://www.audiworld.com/forums/a4-.../#post25196184
if your really looking to resolve it there are a few different mods that are out that sound promising to help throttle response. The one that I'm most interested is the TCU+ transmission tune that DT power just released. There is a good thread here in the B9 S4 forum on the product. From what I read it doesn't completely eliminate the hesitation but supposed to make it a whole lot better.
https://www.audiworld.com/forums/s4-.../#post25212012
There is this thread over in A4 B9 forum on throttle lag you may find interesting to read. This specific post refers to a trick that supposedly reset the throttle map. I don't think this would elimate the hesitation but if you reset it and maybe drove it a particular way you, maybe could get it to feel better.
https://www.audiworld.com/forums/a4-.../#post25196184
if your really looking to resolve it there are a few different mods that are out that sound promising to help throttle response. The one that I'm most interested is the TCU+ transmission tune that DT power just released. There is a good thread here in the B9 S4 forum on the product. From what I read it doesn't completely eliminate the hesitation but supposed to make it a whole lot better.
https://www.audiworld.com/forums/s4-.../#post25212012
10-10-2018, 09:51 AM
#13
Coming from a B8.5 which had either a bug or a 'feature' that would default the car to comfort every time you got in it (it would display auto or dynamic but would 100% be in comfort unless you went from dynamic through the options back to auto/dynamic)...
I thought I'd just have to live with it. The newer cars allow you to set it to auto and it always runs in auto. It took a couple of days but the car adjusted to my 'lazy cruising and then occasional I want to go now' driving style.
I thought I'd just have to live with it. The newer cars allow you to set it to auto and it always runs in auto. It took a couple of days but the car adjusted to my 'lazy cruising and then occasional I want to go now' driving style.
10-10-2018, 10:09 AM
#14
AudiWorld Super User
Last edited by superswiss; 10-10-2018 at 10:12 AM.
10-10-2018, 01:33 PM
#15
Thank you all for posting your similar/same lack of performance from the ZF AT.
I think we all need to make Audi fully aware that we are not happy with the way they programmed this trans.
Here is my experience with this trans in my S4 and two previous BMWs that had this same ZF AT.
The ZF AT is a fantastic transmission. I know this because my last two BMW's, 335i Msport and 340i Msport, has this AT.
In both of those cars the ZF performed beautifully. It was always in the correct gear for cruising, sport driving, or slower speed rural driving up and down hills.
There were three main modes automatic D, D+S, and S.
And there is "manual" mode.
D was default and was on the quick side to get to top gear. With the mode refresh BMW and ZF improved the AT and it is smoother and faster now.
D+S mode is standard Drive in Sport mode.
This would hold gear a bit longer before up shifting giving a good amount of quicker response. Giving part throttle results in proper fast downshift to take advantage of the engines power to keep speed.
S-sport mode is similar to D+S, but holds gear even longer, a good bit longer. It downshifts with greater accuracy and will even drop 2 or 3 gears depending on how I am driving.
For the update BMW improved both D+S and S mode, buy allowing the trans to get to top 8th gear in D+S mode.
In full Driver Sport mode and S trans mode, top 8th gear would only come on automatically if car speed was above 70mph at steady highway cruise.
In the BMW in full driver select Sport mode in trans Manual mode, the trans would not up shift on it's own at all.
I could hit the rev limiter and it still wouldn't up shift.
The rev limiter would keep rpm in check.
Also, I could quickly do multiple down shifts, even up shifts.
I could go from 8th and quickly pull the down shift 6 times and the trans would skip to 2nd as fast as I could do it in a manual trans.
For up shifts, I could be in 3rd and do 3 quick up shifts on the lever, or paddles, and the trans would skip up to 6th or more if I want.
In my S4 I can't do that. Manual mode is much slower, and likes to be more like a sequential shift.
If I use the up shift paddle and try to hit it 4 times the trans seems to want to do 4 shifts and not skip.
Down shift is worse as it's much more common to want multiple down shifts. If I'm in 7th and I quickly pull down 4 clicks again it won't do it quickly, like it's waiting for me to make sure I really want that.
And yes, I'm not asking for a gear that will over rev the engine.
The ZF AT in the S4 is programmed VERY poorly by Audi.
It is not ZF's fault, nor the design of this AT, as proven by it's excellent and super fast and smooth operation in the BMWs.
In D mode the trans wants to go to top gear as fast as possible. In the BMW that was like "economy" mode plus regular D, with a very slow throttle response and up shifts too fast.
In my S4 in D mode up shifts happen before 2000rpm on light acceleration throttle. That is MUCH too low of an rpm for ups shifts.
On steady cruise on rural roads, in D mode, the trans will shift to 8th gear by 40mph. That puts the trans a tick above 1000rpm!
That is much too low. If I come to a small hill and give it a bit of throttle to maintain speed, all I get is that torque converter windup with no downshift.
I have to actually give it a good amount of throttle to wake the trans up.
S mode is a bit better. It is a bit more responsive, but nothing like Sport mode should be, as it is in the BMW.
In our S mode the system will hold gear a bit longer maybe another 500rpm, it depends on how much throttle we give.
But, it still wants to shift up as soon as possible, which is not good.
And, there is no other Sport+ mode to help things out.
To get the best performance and response in order to get some feeling of performance, I am using S mode to get up to speed, and then pull back on the gear lever for D when I'm above 60mph to take advantage of the lower rpm for better fuel economy.
S mode will shift to 7th if you are in a steady cruise speed, iirc, 50mph and above.
To get to 8th while in S mode you have to go to D mode.
Over all, this trans is lazy and unresponsive not because of ZF's design, but because Audi programmed it very poorly.
The only way we can get Audi to correct this massive error is to keep reporting the issue to our dealers and directly to Audi.
The Audi techs will not consider this a problem as the trans is functioning as programmed.
Still, we need to make sure that the service advisers note the "driveability" problem so that Audi can work on correcting the programming to bring this car up to the performance level is should be at.
The 340i Msport I just had was a 2016 model, and that 3 series is no longer being made. It's now an old chassis, and still it had a vastly superior performing ZF AT, that is the same trans as in our S4, even the gear ratios are the same.
Also, I just had an A4 with the dual-clutch DSG, and even though owners complain that it too is lazy at times, I found it to be much better programmed and more responsive in both D and S modes.
Overall shifts with the DSG are smooth, but not as smooth as the ZF, and certainly not any faster. The ZF is capable of super fast shifts, and it can do multi-gear downshifts faster than a dual clutch.
Audi didn't program it properly to take full advantage of what this trans can do.
It's NOT the engine, and it's not the turbo in this engine.
This V6 turbo is quite nice and powerful.
The 3.0 inline-6 in the BMW is a sweet engine as well, over all, it's smoother at idle and a bit smoother are higher rpm.
It too has a twin scroll turbo, just like our V6.
With a twin scroll there are two different exhaust inlets to the hot side of the turbo.
One inlet is fed by one bank of 3 cylinders, and it's design is optimized to spool up the turbo faster at lower rpm.
The other inlet is fed by the other bank of 3 cylinders, and is designed to optimize the turbo at higher rpm.
Twin scroll is a very good and advanced turbo design.
It's basically like using tuned headers for a turbo, rather than the old method of using the whole exhaust manifold.
As everyone has noted, the throttle is programmed to be lazy by not giving enough intake opening at part throttle, couple that to auto trans programming that favors up shifts way too soon, and the trans down shift smartly, and we have an overall feeling and experience of lag, lag, lag everywhere including throttle and trans.
We really need to complain to Audi to correct this.
The stop sport sedan models, S4/S5 should not be so unresponsive, especially given that BMW programs this same AT beautifully.
I know there are throttle boxes and AT reprogramming products, but the trans programming is $550 and the throttle box is, IIRC, $350.
That's nearly $1000 for something that Audi needs to address and correct, because we already paid for added performance not just a more powerful engine.
I think we all need to make Audi fully aware that we are not happy with the way they programmed this trans.
Here is my experience with this trans in my S4 and two previous BMWs that had this same ZF AT.
The ZF AT is a fantastic transmission. I know this because my last two BMW's, 335i Msport and 340i Msport, has this AT.
In both of those cars the ZF performed beautifully. It was always in the correct gear for cruising, sport driving, or slower speed rural driving up and down hills.
There were three main modes automatic D, D+S, and S.
And there is "manual" mode.
D was default and was on the quick side to get to top gear. With the mode refresh BMW and ZF improved the AT and it is smoother and faster now.
D+S mode is standard Drive in Sport mode.
This would hold gear a bit longer before up shifting giving a good amount of quicker response. Giving part throttle results in proper fast downshift to take advantage of the engines power to keep speed.
S-sport mode is similar to D+S, but holds gear even longer, a good bit longer. It downshifts with greater accuracy and will even drop 2 or 3 gears depending on how I am driving.
For the update BMW improved both D+S and S mode, buy allowing the trans to get to top 8th gear in D+S mode.
In full Driver Sport mode and S trans mode, top 8th gear would only come on automatically if car speed was above 70mph at steady highway cruise.
In the BMW in full driver select Sport mode in trans Manual mode, the trans would not up shift on it's own at all.
I could hit the rev limiter and it still wouldn't up shift.
The rev limiter would keep rpm in check.
Also, I could quickly do multiple down shifts, even up shifts.
I could go from 8th and quickly pull the down shift 6 times and the trans would skip to 2nd as fast as I could do it in a manual trans.
For up shifts, I could be in 3rd and do 3 quick up shifts on the lever, or paddles, and the trans would skip up to 6th or more if I want.
In my S4 I can't do that. Manual mode is much slower, and likes to be more like a sequential shift.
If I use the up shift paddle and try to hit it 4 times the trans seems to want to do 4 shifts and not skip.
Down shift is worse as it's much more common to want multiple down shifts. If I'm in 7th and I quickly pull down 4 clicks again it won't do it quickly, like it's waiting for me to make sure I really want that.
And yes, I'm not asking for a gear that will over rev the engine.
The ZF AT in the S4 is programmed VERY poorly by Audi.
It is not ZF's fault, nor the design of this AT, as proven by it's excellent and super fast and smooth operation in the BMWs.
In D mode the trans wants to go to top gear as fast as possible. In the BMW that was like "economy" mode plus regular D, with a very slow throttle response and up shifts too fast.
In my S4 in D mode up shifts happen before 2000rpm on light acceleration throttle. That is MUCH too low of an rpm for ups shifts.
On steady cruise on rural roads, in D mode, the trans will shift to 8th gear by 40mph. That puts the trans a tick above 1000rpm!
That is much too low. If I come to a small hill and give it a bit of throttle to maintain speed, all I get is that torque converter windup with no downshift.
I have to actually give it a good amount of throttle to wake the trans up.
S mode is a bit better. It is a bit more responsive, but nothing like Sport mode should be, as it is in the BMW.
In our S mode the system will hold gear a bit longer maybe another 500rpm, it depends on how much throttle we give.
But, it still wants to shift up as soon as possible, which is not good.
And, there is no other Sport+ mode to help things out.
To get the best performance and response in order to get some feeling of performance, I am using S mode to get up to speed, and then pull back on the gear lever for D when I'm above 60mph to take advantage of the lower rpm for better fuel economy.
S mode will shift to 7th if you are in a steady cruise speed, iirc, 50mph and above.
To get to 8th while in S mode you have to go to D mode.
Over all, this trans is lazy and unresponsive not because of ZF's design, but because Audi programmed it very poorly.
The only way we can get Audi to correct this massive error is to keep reporting the issue to our dealers and directly to Audi.
The Audi techs will not consider this a problem as the trans is functioning as programmed.
Still, we need to make sure that the service advisers note the "driveability" problem so that Audi can work on correcting the programming to bring this car up to the performance level is should be at.
The 340i Msport I just had was a 2016 model, and that 3 series is no longer being made. It's now an old chassis, and still it had a vastly superior performing ZF AT, that is the same trans as in our S4, even the gear ratios are the same.
Also, I just had an A4 with the dual-clutch DSG, and even though owners complain that it too is lazy at times, I found it to be much better programmed and more responsive in both D and S modes.
Overall shifts with the DSG are smooth, but not as smooth as the ZF, and certainly not any faster. The ZF is capable of super fast shifts, and it can do multi-gear downshifts faster than a dual clutch.
Audi didn't program it properly to take full advantage of what this trans can do.
It's NOT the engine, and it's not the turbo in this engine.
This V6 turbo is quite nice and powerful.
The 3.0 inline-6 in the BMW is a sweet engine as well, over all, it's smoother at idle and a bit smoother are higher rpm.
It too has a twin scroll turbo, just like our V6.
With a twin scroll there are two different exhaust inlets to the hot side of the turbo.
One inlet is fed by one bank of 3 cylinders, and it's design is optimized to spool up the turbo faster at lower rpm.
The other inlet is fed by the other bank of 3 cylinders, and is designed to optimize the turbo at higher rpm.
Twin scroll is a very good and advanced turbo design.
It's basically like using tuned headers for a turbo, rather than the old method of using the whole exhaust manifold.
As everyone has noted, the throttle is programmed to be lazy by not giving enough intake opening at part throttle, couple that to auto trans programming that favors up shifts way too soon, and the trans down shift smartly, and we have an overall feeling and experience of lag, lag, lag everywhere including throttle and trans.
We really need to complain to Audi to correct this.
The stop sport sedan models, S4/S5 should not be so unresponsive, especially given that BMW programs this same AT beautifully.
I know there are throttle boxes and AT reprogramming products, but the trans programming is $550 and the throttle box is, IIRC, $350.
That's nearly $1000 for something that Audi needs to address and correct, because we already paid for added performance not just a more powerful engine.
Last edited by TT-S4; 10-11-2018 at 09:52 AM.
10-10-2018, 02:01 PM
#16
AudiWorld Super User
^^ It has been brought up in the past, that Audi lacks an in between mode. Even though Audi has three chassis modes, the transmission and engine only have two. Comfort and Auto are actually the same. I think BMW and Mercedes have gotten this right by having two sport modes and one normal mode, but even the normal mode is responsive when it needs to be. Mercedes in particular who develops its own transmissions and then AMG gets a hold of it, turns it up to 110% and replaces the torque converter with a startup clutch. Done right the ZF8 can be a great transmission, but the AMG MCT is a notch above. However as said I think having two sport modes makes a difference. In some markets such as Europe, Audi slots in an Eco mode below Comfort, which actually adds a third mode to the transmission/engine, but from what I've read, D isn't any better in markets that get the E mode.
10-11-2018, 09:13 AM
#18
@JohnEnglish is correct. The B9 is no different from the B8.5 in this regard. Both stay in the last selected Drive Select mode. The only thing that reverts back to Comfort/Auto are the engine/transmission/exhaust setting due to regulations. Both always start in D, even if you had it in S before turning off the car, but everything else stays in the mode you had it previously. I also keep my B8.5 RS5 in Individual mode with everything in Auto, but the Sport Differential in Dynamic and it stays that way for at least 90% of my driving and a quick pull on the shifter engages Dynamic/S mode for the engine/transmission if I feel a bit more frisky temporarily w/o having to switch the entire car to Dynamic.
If I put the car in dynamic mode, turn it off, and come back and it displays 'dynamic mode' I expect the e/t/e along with everything else to be in dynamic mode or to go back to (and display) comfort mode. I don't expect a weird mis-mash of settings or to go from dynamic mode to something else back to dynamic mode.
The dealer told me this was expected, hence the phrase bug or 'feature' to do this. My B8.5 was acceptably programmed in comfort mode so I just left it there unless I was driving hard where the differences were profound.
As I mentioned before with my B9 it's very difficult (for me) to drive smoothly in comfort mode. Setting it to the auto preset works across restarts and fixes the issue for me.
10-11-2018, 10:05 AM
#19
I use "individual" mode pretty much 95% of the time, and trans is selected to "dynamic".
However, every time I start the car the trans is in "D" mode not "S".
To get it in S mode I have to pull back on the gear lever, which is not a big deal, or go back into the individual mode in MMI and re-select it.
However, every time I start the car the trans is in "D" mode not "S".
To get it in S mode I have to pull back on the gear lever, which is not a big deal, or go back into the individual mode in MMI and re-select it.
