991S PDK throttle hesitation from start
 

Have a May'12 build 991S, PDK, S-Chrono, S-PASM, 11k km. Now that summer weather has arrived, and driving-like-I-stole-it whenever possible, a throttle hesitation issue has come up.

On fast acceleration from a stop, the initial few hundred RPM's from idle, there is a hesitation. This is in manual or auto, Normal, Sport or Sport Plus.

Smooth application of throttle from start, this does not happen, but only when I hit the throttle as to get into traffic quickly. I haven't tried hitting the kick down button in this way as generally getting into traffic entails a 90 degree turn and I'd initiate a spin.

I've tried a left foot on brake pedal and raising throttle to 1,500 rpm type launch but that is not practical.

What is your experience?

Exact same for me (991-4S PDK). There is maybe a 1 second (?) lag when the accelerator is depressed aggressively from a stop when it feels like nothing is happening.

I just recently figured out that smooth application doesn't give you that lag but haven't played with it enough to figure out if I like that approach better.

I saw that thread at the time but not the end of it where it talks about the lag from a start so thanks for the link. FWIW I've never noticed an issue in 2nd gear or in the 2,500-3,000 rpm range. Interesting.

Made this video today to try to demonstrate the throttle response or acceleration hesitation issue.

I have the same car and have not noticed it... although compared to my Cayenne diesel with all the low end torque, the 991S seems slow at low rpm. I chalked it up to being a low torque, high rpm engine. Maybe a software tweak can fix it for you. I couldn't really see it in your video, I guess because I can't see the tach or your accelerator pedal.

Nice troubleshooting video.

Now, have you taken the service manager at the dealership for a ride to demo it to him?

I do notice the relatively low torque of the 991S before about 2,500 rpm at which point it comes alive. This is much before that at 900 rpm. I was concerned as well that the acceleration hesitation would be hard to see on the video. I'll try your suggestion - video of the tach and pedal.


Have an appointment July 18.

Let us know what they say. I chalked it up to PDK feathering the clutch to avoid excessive wear.

It is an automatic manual. Would you expect that feeling if you were releasing the clutch?

I know most here love their PDK 991's but I highly recommend a test drive in a 6 speed automatic corvette for a reminder of what a sports car that jumps off the line from idle feels like!

Good point. Definitely would not expect it...but beats me how a computer does it ;)

you nailed it right.many po owners found that out the hard way when they pulled up to a vette at a traffic light:bowdown::bigbye:

I had the update performed last Friday and have noticed the same thing. Immediately upon acceleration, there is a slight hesitation before the vehicle actually gets going. I've noticed this in all modes.

I think 911 owners are well aware their car is NOT a drag racer (read American Muscle) and more of an overall package (handling in addition). Don Garlits I'm not looking to be... Emerson Fittipaldi maybe...

So this was not an issue before the update?

What is the date of your build and have you had any previous service updates?

Mine is a May 14 2012 build and no updates. First to be Jul18.

This was not an issue prior to the update. I immediately noticed the hesitation when I punched the pedal from a stop or a slow roll. I have a November 2012 build and no product updates.

Buy a 997.2S :) JK. But I have no hesitation on my 997 w PDK. It moves off the line fast without delay when you hit it.

Seems like there's an issue that needs to be resolved.

I just did the update and drove a couple hundred road miles and a track session at Laguna Seca. It's okay, but not improved. Throttle tip-in is vague (be it from a standstill or various conditions going from a closed throttle to applying power) and there's some sort of hesitation around 3000-4000 rpm that I've diagnosed, but it's not intrusive and I've not had the opportunity to try to video the tach/speedo to see where it's happening. Downshifts are harsh and it still has a way of not quite getting the engine stop-start "right." I've read that Porsche is working on a stop-start for future models and model years that will allow the engine to shut off while the vehicle is moving below something like 10 km/h under brakes (which seems to me to be a good way to get around some of the problems.)

Any updates on this hesitation problem? It seems to be a common occurrence on most base model (2.7)981s with PDK having the hesitation from a dead stop. Owners have complained to Porsche with no positive results.

I have the same problem on my S.

I think this is an Porsche/Audi/VW wide problem. I have a newish Jetta TDI that has the problem the worst. You are never sure how long the lag will be. If you put your foot on the brake and push down on the accelerator nothing happens...the tach doesn't move a bit. My '06 A6 Avant has the same problem that is not near as bad. It happens much less often and the lag is less but crossing the highway in front of an oncoming dump truck can be a sphincter tightening experience. The lag that I notice on my April '12 build C2S with PDK is mostly when the engine is not yet up to operating temp. In my case it happens at under half throttle. I never floor it until the engine is warm.

As to the post concerning the Corvette's hole shot capability, 6.2 liters against 3.8 liters with cars of similar weight....that outcome is easy to predict.

Hi to you all, I traded my 2012 C63 in on a new 991S with PDK three weeks ago and I have not noticed any hesitation. Coming out of the AMG I expected to be disappointed down low but it has been a pleasant surprise.

I've also noticed the hesitation from a stop in my 2013 C4S. Had an M3 with DCT as last car which didn't have the issue so you can't blame it on the absence of a torque converter. I'm a little disappointed and hope Porsche will address it.

This is an interesting coincidence. I just finished reading multiple threads on the "PDK versus MT" threads as I get closer to deciding the final build on a 50th anniversary. I am wondering how pervasive an issue this is. Clearly, PDK proponents in previous threads LOVE their PDK's and for understandable reasons but I have not seen this issue in previous threads (maybe I missed something).
I would really appreciate it if 991 PDK owners would reply to this thread and comment on whether or not they have or are experiencing this. This would help folks like me who are still considering which tranny to go with and if this is issue is more pervasive, it may help push Porsche to address in a more timely fashion.
Thanks....

different car but same issue. 09 cayman base pdk. if i try to power brake it ,even a little ,i get lag. if i just release the brake and nail it i have no issues aside the car has very little torque.......but that is another issue.i have noticed that on winter days the trans can be a little "sleepy" the first minute or so of driving.i do like pdk...........but i am old.imho

I had a 991 C2 MT and now have a 991 C4S with PDK. Even with the hesitation issue from a stop, I still far prefer PDK. The lag reminds me of the delay you get as you let out a clutch on the MT. It just doesn't pop off the line as you'd expect from an automatic or a BMW DCT (getrag if i remember correctly). I like the PDK because you don't get the torque interruption as you work through the gears. It's much faster and smoother. I also hated the clutch on the 991 MT and thought it was way to stiff. I drive a 996TT and thought the manual execution on that car was much better although maybe too much boost. Porsche and ZF need to iron this out. Hope it can be fixed with a software patch.

Thanks for the follow-up and I look forward to reading more of these.
Has anyone either reached out directly to Porsche USA or asked their dealer to do so?

Identical problem with the 981 Base with PDK. There are currently 100 posts to a thread titled "Base Boxster hesitates from a dead stop". It affects the Base 2.7 981 Boxster/Caymans with PDK. The manual and S models do not seem to be affected.

http://www.planet-9.com/981-cayman-b...dead-stop.html

Maybe they fix it in the GT3 PDK-S

No issues on my 2013 C4S manual. Are folks only noticing this with PDK?

My Jan 2012 C2S has not had any hesitation problems from start. I think I can feel variations in response related to the torque curve when getting on it at various speeds, but it does not seem to be a PDK issue.

Had my service done last week with May PDK software update installed. No change in anything noticeable. Service manager tried other 991S's with PDK and found they all have this issue.

The throttle/acceleration hesitation is a delay. Hit the throttle hard from a stop, jumps 100 rpm from idle, delay, then continues without issue. No throttle hesitation issue when not in gear.

In Normal mode, idle is at 700. Hit throttle, it jumps to 800 rpm, delay, then keeps going.

In Sport and Sport Plus, idles at 800. Hit throttle, it jumps to 900 rpm, delay, then keeps going.

I think you've described it quite accurately.......now what are the chances that Porsche will come out with a fix? It is obviously affecting quite a few PDK cars both 991 and 981 recently. Is there anything that can be suggested to the owners of these cars to be more proactive?

I am not certain this is a 'problem', but perhaps it is just the ECU pre-managing the potential wheel-spin issue when accelarating strongly in the lowest gear (as it doesn't happen in the higher ratios).

There is no delay with launch control. Not an issue if you hold brake, paddle to N, rev to any rpm above idle, paddle to 1st and drop the brake - kind of launch.

Traction control on or off, no difference in any method of acceleration from a dead stop.

If the ECU is "pre-managing" for about .25 seconds than it is thinking in Neanderthal mode. Something else is at play.

We used to call this a "neutral drop" back in the say on automatics which was really hard on the transmission. Any reason to think it would be different on PDK?

Not likely. Search the GT3 forum for the video of the pre-production car that they were driving it onto a trailer and it kept stalling. I have a feeling it is intentional for clutch longevity.

when i was buying my car last summer, the PDK delay was the reason i went with a 7 speed MT. I had a deposit on a car with PDK with sport chrono, and the constant sensation of the car hesitating when i dropped the hammer drove me nuts. To me, it wasn't worth 5 k for the PDK if it hesitated, I can do that for free in my MT. However my wife's 2013 Audi S4 Stronic is a jackrabbit off the line in dynamic mode....

I have a March 2013 C4S and have been annoyed by the hesitation from standstill. Major issue when I'm looking for a small gap in traffic in main road when I'm trying to join from side street - I need to leave a much bigger gap because of this hesitation!

Told my service manager and was told this is normal.

FWIW, in that vid the driver stalled it once while trying to slowly crawl up a ramp into a narrow enclosed van. Watch from the 1:10 mark:

The GT3 PDK is structurally different. Different in the clutches and in the mechanisms. Also, the GT3 has two idle modes, one "free" (no creep) and one with "torque convertor" creep.

I have a 2012 S with sport plus, etc. It has the flat spot, it has throttle tip-in lag and from a standstill it has lurching and lag, but only with a closed throttle and very light throttle movements. If you just "accelerate" as in jumping into a gap in cross traffic, it shows no lag or hesitation. I've had the update and a couple of people drive it, including techs and the service manager, and friends who have other dual clutch cars. They all declare it "smooth, fine, nothing to notice" ... I think there's a level of expectation and I expect better, but people coming out of other dual clutch cars have different expectations or different "but dyno" calibration. I dunno. PDK is a long way from 100% developed, if you ask me. It's awesome on track and wide open in Super Duper Sport Double Plus You Betcha mode, but it's a clumsy oaf if you're in slow-n-go commute traffic or just rolling up to a stop light. I'm "conditioned" to just put it in N whenever it's likely to make a mistake. : ) Speaking of which, I wish Porsche didn't put the "idiot" lights (PRND) on the dash, it's just so crass. By all means, put up a numeral when a gear is selected manually, but otherwise ... seriously?

My understanding is that PDK-S in the GT3 has no "torque converter" creep off idle at all, in any mode.

This seems to me to be absolutely unacceptable. Who steps on a gas peddle expecting to go forward and waits for something to happen? On top of it all, this is a sports car that's known for it's immediate response to acceleration. Are they kidding?

This issue has also been reported by some Panamera owners. So it's not just a 991 issue, but a PDK issue.

I suspect that if you were to take it into the dealer for a fix, the response would be "they all do that".

No.
They'd say : " It's normal ".
:confused:

" Customer complaint : a slight hesitation from standstill
Customer thinks it's related to PDK
Technician tested the car using PIWIS and 20 min drive.
Technician's conclusion : found the behavior NORMAL and within factory specs "
:)

Hate to say it but it is a design problem most likely that won't be ironed out until they re-engineer the ECU system on PDK models..............I have had 2 German cars with similar system issues - hesitation - that have been re-flashed with no or little improvement..........problem solved when the entire ECU was redesigned with their next model update......both manufacturers denied there was an issue.....sort of like the IMS fiasco class action suit on the 996....what problem, it is "normal"......and actually it is "normal" for the design they developed............"the Germans might not be right, but they are never wrong culture......."

I read each of the mode descriptions somewhere. Someone posted a description here, but suggested every mode omits the "automatic" creep. I think that's fine, if so. It was a bit peculiar because I read somewhere that in one mode it would never upshift automatically. I have to assume it will upshift if the throttle has depressed the "kick down" button (pushing past wide open to depress a button) which is true for Sport Plus in the 991S and the 997S. We'll know soon enough.

The GT3 has hill "hold" so it shouldn't matter too much, but if you're driving in traffic and the clutch has to transition repeatedly from engagement and slip to free, I hope Porsche made the initial engagement a very smooth transition with a partial throttle.

Between the floppy "P for Park" automatic nature of parking with the PDK (and therefore being forced to use the "whirrr ... dunk" electric parking brake, Porsche has taken away two of the things you can use to recognize a driver taking care when they use their car. You can always tell the mechanically "sympathetic" from the guys that just wrench on the parking brake as hard as they can, as if arresting the car on a double black diamond ski run, rattling the ratchet across every notch so loudly you can hear it from the other side of the shopping mall parking lot. You can appreciate a driver that can slow to a smooth halt, precisely in the parking space, no curb rash, no steering gear forced to hold the weight of the car on the shoulder of one front tire; and exit the car without it lazily flopping and rocking on the "P" transmission tooth like an absent minded cop rushing to the donut store.

Just as it should be possible to move the car forward without the transmission when and how that will happen, the driver should be able to slow to a halt without the transmission injecting brief head-nodding disturbance through a half dozen downshifts into every red light even though the car is on a closed throttle ... where's the benefit to the driver or emissions or anything to do with the car by blipping down from 7th to 2nd then shunting into 1st just to make sure nobody forgot the driver can't drive smoothly in this car.

Hopefully in future generations of the 911, the engineers and designers will pick up on these finer points and, like the simple things (the door mirrors actually on the door instead of the A pillar, the window switches on the door panel) they'll revisit the blatant mistakes of the 991 and get the 911 back on track -- literally and figuratively.

I think Porsche has to look at their position in the market. To the south, there's the Corvette, which now merits serious comparison to a Carrera, if not a GT3. Yet. Bring on the Z06 to challenge the GT3 and the ZR1 to challenge the GT2. To the north, there's the 458, which is a dramatic advance over the F430. There's soon to be public information on the 458 Monte, said by some "in the know" to be more mechanical and much lighter. Isn't that exactly what we're all asking of the GT3? But it's heavier, and more electronic. Just as Porsche makes its move on the playing board, both GM and Ferrari have pieces in position already, and the next two moves appear to be in jeopardy.

In manual mode PDK-S in the 991 GT3 will not upshift automatically under any circumstances and there is no kickdown feature. This is true regardless of whether the car is in default mode or PDK Sport. I'm 100% sure about this.

This differs from regular PDK where, as you point out, even in manual mode there is a kickdown feature, and once the kickdown is implemented PDK will continue to upshift at redline automatically until you let off the throttle. Once you let off it returns to manual mode.

I don't think that PDK-S has hill hold. Other "special functions" associated with PDK like sailing, eco-shifting, and start stop aren't included either. Likewise your comment about multiple downshifts as you come to a stop; again in manual mode the car will downshift once just as you are about to stop so as not to stall the engine. Otherwise you must downshift for yourself. This is the same way the DCT in the Ferrari 458 operates.

Speaking of the 458, almost every reviewer so far has compared the 991 GT3 to the 458 very favorably, saying it will have comparable, if not better, performance at a price that's $100K less. If true, that sounds like pretty decent market positioning to me. As you say, we'll know soon enough.

:roflmao:
Brilliant writing as usual CarreraGT!
:thumbup:

Just so long as there's the equivalent of a Sport Plus mode so that PDK makes all the right decisions to upshift and downshift for best possible power to the ground, best possible throttle response, best possible torque response. I shake my head when I see journo's and "test" drivers running acceleration tests and they paddle the upshift -- if they want best possible performance from the car, it has to be the computers timing the perfect upshift for the conditions. A tiny headwind or uphill grade and the computers should adjust to upshift into the meat of the torque curve, a little tail breeze or downhill and the computer can make the calculations to upshift screaming into the last ignition pulse and the last crank rotation at the redline, and the driver can keep eyes and brain on steering the line.

If PDK is now smart enough to go to open clutches as the car slows under brakes during calm driving, that's great. I read somewhere either the next iteration of the 911 or the Panamera software will also stop the engine if the car is slowing, as if to a halt at traffic lights (something like 8 mph with brake applied.) That simple logic update would avoid most of the head-nodding and shuddering and wrong-footed mistakes of PDK in the 991.

PDK-S in auto mode makes decisions exactly the way you describe, with PDK-Sport being the equivalent of Sport Plus and taking the engine all the way to redline before upshifting. The difference being that those upshifts in the GT3 now happen at 9000 rpm. :)

In the end,what's different in the PDK-S than PDK in terms of internals?
Shorter gear ratios...we know...and software...

Maybe they'll use the PDK-S software in the 2nd gen PDK and this hesitation will go away...

The PDK-S differences we know:

shorter ratios
shorter shift times <100ms
top speed achieved in 7th
no crawl from idle in either auto or manual
no buffering of engine torque between shifts (Porsche calls it "torque overshoot")
just the two sport modes (no default eco shifting mode)
a true manual shift mode with no auto kickdown and auto upshifting at redline
elimination of special features (sailing, start stop, etc.)
shorter and more tactile paddle operation
reversed console stick operation with a revised stronger spring
lighter weight (a kilo or two IIRC)

As far as specific internal changes (size of clutches, mods to the geartrain, materials etc.) I'm not aware of any published info about that. FWIW, in one of the recent reviews, Porsche has claimed to have done 1000+ launch control starts to a PDK-S gearbox without failure.

Thanks Mike!
I pretty much knew all of these features,I was wondering if someone would have more information about internals. I guess we won't know more until someone decides to disassemble both and see the differences. Seeing how Porsche decided to change their strategy even with the GT department to make more profit(I wonder if VW had anything to do with it...), I wouldn't be surprised if PDK-S internals are not all that different from PDK's internals,in which case a PDK.2 so called " update " will come up pretty soon.

So, is this hesitation problem something that everyone is affected by or are recent production cars not having this issue? All I've read about the PDK is that it's sublime but this hesitation issue has become a subject out of the blue in just the past month. Where has everyone been the past year that this subject only just now surfaces?

Got mine in April 2012 and it has never hesitated.

That's good to know, Chuck. Maybe a poll of the membership can determine how many are and how many aren't affected.

Got mine three weeks ago and no hesitation.

Maybe a build date poll. My MY13 C2S PDK has a build date of Jan 2013 and I have the hesitation.

I didn't notice it for many months during the break-in period and not until I started driving it more aggressively.

Find a safe place without traffic. A parking lot will do as you will only need to accelerate from idle to say 1500 rpm and stop. Stare at the tach during this and you should be able to see it as well as feel it. Once you do, it will be staring back at you!

Simply floor the throttle in 1st from a stop and you will experience the following;
In Normal mode, idle is at 700. Hit throttle, it jumps to 800 rpm, delay, then keeps going.
In Sport and Sport Plus, idles at 800. Hit throttle, it jumps to 900 rpm, delay, then keeps going.

If you are smooth with the throttle, you may not see/feel it.

It's almost gives a sensation of turbo delay

Hi Carman, I took the car out today just to test this and I honestly have no hesitation. I traded in my 2012 C63 so I am used to immediate acceleration from a stand still. I can't fault the thing. I must say it is a rough change down from 2nd to 1st with the PDK if you are moving slowly. Having said that, the AMG was very similar and that never bothered me. Maybe it will develop over time, something to look forward to......not.

I also had the rough change from 2nd to 1st but after a recent software update it no longer thumps, it's actually very smooth now. I also (still) have the hesitation but it doesn't really bother me. The dealer said it was normal......as they all say...

Hmmm . . . . no hesitation. Just to be sure, you have to stomp the throttle, like a drag race.

Well maybe there is something "wrong", but in the end it's right! I didn't notice it for several months and attribute that to non aggressive driving and not being as in tune/familiar with the car as I am now.

Can you send me your PDK ECU? ;)

Without having experienced it yet, but based on all the comments, I've come up with a theory as to how to avoid the experience: Don't got straight to WOT from a standing start unless you're in launch control mode. Spirited driving on streets with traffic usually doesn't call for WOT from a standing start and you can get very spirited driving off the line with 3/4 throttle. Only go WOT once underway or during launch control. Problem solved.

Most certainly, if you go easy for the initial few hundred rpm and then floor it, you can avoid the delay sensation.

On the street with a 991S, WOT from a standing start is way beyond "spirited driving", well on the way to gonzo-nutso.

100% agree. I think those who are complaining about the delay are doing just that, though. Maybe on a deserted street and not in traffic, but it seems that the perceived lag is when WOT is initiated from a stop, not something to be done on streets, anyway.

Regardless, it's rather a pain in the rear to have a car that decides what it wants to do rather than doing what the driver asks it to do. I can think of a number of emergency situations coming from a standing start where a delay could be a safety issue, and no amount of excuses makes it OK.

What's really annoying is the manufacturer calling it "normal" operation.

In 50 years of driving I have never had the need to make an emergency WOT from a standing stop. If you want to WOT on street roads during normal driving, that's your business but you're going to have to adjust to the new normal. Otherwise, hit the gas off the line but just don't floor it and - voila! - no hesitation and probably no speeding ticket, either.

BS - a lame response. In an emergency situation, 99.99% of people will either floor it or slam on the brakes. The operation of the PDK is flawed in at least two ways that have been clearly identified by a LOT of drivers; why do you continue to make excuses for it?

Perhaps "flooring it" is not the correct term in that a spirited start from stop does not entail nor require leaving the pedal there until you are driving reckless. A simple quick 1/4 throttle will expose the delay.

Honestly, some of you are taking this way out of proportion in the thinking that the issue only occurs if you are driving "gonzo-nutso".

The delay only occurs at 100 rpm above idle and is more perceptible the more aggressive you are with the throttle. Tonight in normal mode and a just quicker than the next guy acceleration from stop (which for the 991S is completely lame) and the delay is there.

Take a look at my video in posting #5 to see how "gonzo-nutso" I am driving to expose this issue.

No excuses Porsche, just fix it.

I have no delay. That aside, 300 milliseconds would be 1) likely inside the variability in any sample of driver response time and 2) likely irrelevant in your hypothetical emergency statistic.

Posters here have shown actual 1/4 mile time slips as low as 11.7 seconds for the 991S. You will something with another hundred HP to beat that.

Not to take a stand one way or the other on whether the PDK delay is a meaningful problem or not, or should have been engineered away, but it is consistent with the fact that PDK is an automated manual gearbox with internal clutches. The clutch for the shaft with 1st gear is only lightly engaged at a stop to simulate auto transmission crawl and, unlike launch control conditions, isn't programmed to instantaneously "dump" under a sudden throttle application. It takes a brief moment to engage fully and transmit power.

For comparison purposes, imagine you're at a stop in a MT car with your foot on the brake, the clutch depressed, and the transmission in gear, the best possible scenario for a quick take off in an "emergency". I'd suggest that the time it takes to leave the brake, mash the throttle, and dump the clutch is hardly less than it takes for PDK to perform the same function internally. Many people would be on the brake, off the clutch pedal and in neutral at a stop and in the same emergency situation under those conditions it wouldn't even be a contest vs. PDK.

Just another perspective.

And a good one.

The time it takes an Auto transmission to make the car move from a stop when " mashing " the throttle should be 0s(instantaneously)! That was valid with the old single clutch tranny,why wouldn't it be true with the Double Clutch?

Watching your video, I think you are feeling the accumulated effect of e-throttle response, pdk clutch engagement and engine torque response.
If this really bothers you, you might be a good candidate for an electric car!

That is because they used launch control, where this delay issue does not exist.

No one is suggesting that the PDK doesn't offer amazing performance or that the delay causes a shorter 0-60 time, or in some way diminishes overall performance.
This is one amazing piece of engineering!

What the delay causes is a lack of smoothness on that initial punch of the throttle. That is what is annoying.

The take-up coding needs to be tweaked to eliminate this issue. In the next few months when the GT-3 gets into members hands we will know if this issue has been sorted.

No fluid coupled automatic transmission that I've ever driven has had "0sec instantaneous" response which is why most acceleration tests of auto trans cars, even before LC, were done by running up the engine against the brakes to load the torque converter. I haven't had experience with a single clutch auto manual so can't compare to a DCT. But from what I've read their operation is generally rough and abrupt around town so maybe there is a programming trade off. AFAIK, there's nothing inherent in the design of a DCT that would keep it from operating similarly to a SC auto manual, assuming the manufacturer wanted it to.

The only time I ever noticed this issue with my 997.2 S was off the line under WOT while autocrossing (not using launch control), never under any kind of normal or even aggressive street driving. Maybe the 991 PDK programming is "softer" in this regard and it's more noticeable in everyday use. It will be interesting to see how PDK-S is programmed in the 991 GT3.

Porsche never had a single clutch automated mechanical transmission. With its best manual transmission, attempting an instantaneous jump from a standstill more than 300 ms would be lost in slipping the clutch, spinning tires or most typically axle tramp and or engine bog, depending on how merciless one is with drivetrain mechanicals.

But thats not really the issue here- it is the apparently obvious enough delay that some are feeling and that they wish was not there. If folks are reporting it, I believe they are observing it. From the description one hopes it is sensor/software response and not clutch slipping. I bet the little sucker is very expensive to repair!

Mike,there's no delay or hesitation in any automatic transmission,at least not perceivable by one...you press the gas,you go!
I haven't noticed this issue with PDK the few times I've driven one,but I can understand why this would be annoying at some point...

As I understand it, with conventional automatics, there is always delay, smoothed over by the stator slipping until the fluids are spinning at the same speed. The best of them lock mechanically after that occurs.

Nick, now we can discuss the interpretation of "no delay"..... :)

As Chuck points out, there is some delay inherent in the design of a typical torque converter automatic; it's unavoidable AFAIK. Maybe PDK in the 991 has more; don't know haven't tried it.

Sorry,I think you've misunderstood my point...I know Porsche used their Tiptronic in older models,which is basically a Torque converter tranny,what I was trying to say is that there's no delay in a single clutch in general,just like there isn't in any Automatic transmissions...

Mike,I guess we can make a whole theory about one's perception of " delay ",but that's not what we're after here...
FWIW,the only time I've noticed a real delay in automatic transmissions is when driven at a constant speed,you decide to floor the accelerator all of a sudden. That's when you'll notice it,while the computer decides to downshift a gear,but never from standstill.
I haven't experienced it in the PDK,but seeing a few of the comments,it certainly seems there is more to it than just " one's imagination ".

I noticed this delay before I read about this in the forum. The delay is noticeable in most throttle applications from stand still, not just at WOT (I haven't even used WOT as my car has just finished 2000miles run-in). It is certainly more noticeable if I use more throttle, but even at 1/4 throttle I can consistenly notice it when moving off from a red light.

Very annoying as I described above when I try to join a main road from a side street -- I need to leave a bigger gap as the delay is a bit variable in duration.

Someone is going to have to document this behavior with a video that includes an accelerometer display and OBDII live data monitor. We need to see throttle position versus acceleration versus time. Until some quantitative numbers are provided that can be used to distinguish a car with the problem from a car without it, there will be no way to make progress towards fixing it.

Picked my 991s up in April, and have been experiencing this issue since. Terribly annoying, almost embarrassing.

I have only had by 2013 991 C4S for one month now and noticed this hesitation. I even remarked about it on an email to Porsche they had sent me to inquire about my experience. It reminds me of previous turbo cars I have owned. It does not take much throttle to notice. I did not realize that others were having issue also.
Cheers.

The e63 has the same issue. I think all dct, dsg, pdk etc trannies have this "issue". Got used to it...almost feels like the clutch needs a tenth of a second to disengage.
I changed my drive habits to roll off stops then mash the throttle.

The new E63? Was seriously contemplating that at my time of purchase.

How do you like it? Or did you just drive it.

Add me to the list. 2013 C4S. Issues began after "transmission software upgrade" at last visit to dealer about 6 weeks ago.

Funny, me too! I test drove the E63 and I liked it fine, but it didn't thrill my soul, you know? Then I thought, "if I'm going to spend over $100K on a car, I should just buy a Porsche". And so I did.

Mine was a 2010 had it for 3 years. Normally aspirated. I really liked it.
But I too noticed the hesitation especially in comfort mode immediately after I pulled off the lot.
It felt real sloppy.

I just changed my drive habits. Always drove it in manual and I feathered the throttle off stops before mashing it.

The other thing the 63 does is if you drive in manual, sport, or sport plus when coming to a stop the car will shift down all the way to first and the shift from second to first can sometimes be real jerky. If your in comfort mode the car will only come down to second and you will start from second at a stop- thus the sloppiness from starting t a stop in comfort.

But the full on power shifts in manual from 2-3,3-4,4-5 are super,super fast and the sound the car makes - you know that pop pop pop is amazing. Its a great transmission.

I drove 991 pdk and it is no where exciting as the e63 the 991 pdk is boring compared to the 63. I think though that the gt3's pdk will be like the 63.

It's interesting that a number of owners have first noticed the PDK hesitation after the transmission software upgrade. If this upgrade initiated or made the hesitation more pronounced, it does leave hope that another future upgrade can reverse or improve the problem.....hopefully eliminate it.

Issue was the same before and after the PDK software "May" update.

Has anyone who has this problem driven another car with a dual clutch transmission?

I have owned an Mitsubishi Evo X TC-SST and an Audi S5 (S-Tronic DSG). The TC-SST has massive insane lag, around half a second. It was one of the reasons why I got rid of it. The Audi DSG is much more responsive and if you slam the gas pedal...it usually moves fairly quickly.

Does anyone who experiences this problem left-foot brake? I started doing this in the Evo X TC-SST to reduce the severity of the lag problem... I would hit the gas while lifting off the brake...this overlap period would help with the lag problem. Sometimes though, when the Audi is coming to a stop, if you hit the gas too soon it will either do one of two things - slam and launch forward like you have been rear ended or bog down and not move for over a second. I prefer the violent slam and launch forward! Dual clutches have quirks.

I test drove a 991 4S and I launched it straight away...in normal driving I did notice that there was some lag (it had sport chrono+). I think I need to test drive it again reading this thread (and not kick the **** out of it so much). If I'm paying $140k for a car, I cannot tolerate a transmission that takes half a second to move.

Exactly. I still don't understand why so many drivers seem to be he11-bent on defending the quirks, rather than on trying to get some focus on fixing the poor performance.

:confused:

One thing I have noticed is that some people assume that because there is a Porsche badge on it, that it's perfect....or....they don't care, as at most of the porsche dealers i have been to, the cars have had purely cosmetic options...e.g. they have sports tail pipes and no sports exhuast! They don't have sports chrono...but have a rear view mirror in leather...they buy the cars for the image and don't drive them.

It's also sad that they don't recognize these things in car reviews....Porsche can put insane launch control on the cars so that they get a great 0-60 time....but when you drive them every day they are laggy and unresponsive.

I find it pathetic that Porsche does not have a solution to this issue. How about enabling the GT3 feature of pulling both paddles and releasing to initiate an instant clutch release?

Good news - it's fixed
 

Took my November 2012 build 991 Carrera S in for its 10.000Km oil change.

This car had the throttle hesitation from stand still as described here in this thread - and yes I agree, it was not a great thing.

Dealer informed me that my car needed its "control unit" updated but did not know what the update did except that it had something to do with the PDK.

I picked up the car and, since it was raining on that day and the roads were wet promptly spun the rears when pulling away from the first traffic light. Hmmm - something had changed.

Anyway, two days later with dry tarmac I could test this a little bit more in detail. Yes, there is no more hesitation left at all. RPM builds instantly with smooth application of clutch a moment later - foot flat and clutch is fully engaged at about 4000 RPM which is reached quickly in any mode. Perfect - could not be better !

Also, in Sport-Plus the gear changes with foot flat are much more violent than before. In fact they are what they where when I first did a test drive in an early 991 back in March last year - but my car sadly lacked the same response - I put it down on me just having got used to it. Clearly, that is not the case.

My 991 has got its 911 Mojo back. :cheers:

Rainier

What is the spec on your laggy and unresponsive 991S?

Had the PDK update on my to do list for months. Didn't think I would notice one way or another so saw no rush. Rainier's post got me in gear to bring it in, though. Thank you mate.

Just picked it up from dealership, but I had my labrador in the passenger seat, and she likes smooth riding better, so looking forward to testing later. ;)

Called to see if there was an update, apparently no updates are due. Just gotta learn to live with it.

my 2013 C4S does this^

Any updates on the hesitation issue?

Does it do it in all modes or just sport plus?

Thanks.

Unless you have a special secret update, this is a GT-3 feature as yet unavailable on any current 991 or 991S version.

Finally got it to work! Originally I was pulling both paddles and keeping them pulled back. Key is to pull both paddles and release them - car goes into shifts into neutral. Also I don't think it's an update issue since mine is a 2012 and the owners handbook describes this feature.

That's what in the new GT3, and yes in normal Carreras you need to release them.

More useful for spirited take off and a potential hesitation issue fix would be:
1. Pull both paddles and hold -> Shift to neutral
2. Adjust appropriate RPM
3. Release both paddles -> Engage appropriate gear (1st if standing still) in quickest possible fashion (like launch control but w/o foot on the breaks, or like quickly releasing the clutch on a manual)
I thought this is what is enabled on GT3 and was hoping to see this as an update for the regular C's - maybe should have gotten the manual after all......

Any new updates with the hesitation? Some 981 members at Planet 9 are pulling their hair out over this issue.

No more issues at all since I had my PDK updated.
It's great. Quick off the line in just the right way. No more need to try and fake it in some other way.
Also better behaviour when overtaking fast - everything has just been sharpened up.
Birdie told me the update is actually similar to the way it was when the 991 was first released. Then they had a few PDK breakages and tuned down the system while they tried to find out what was going on. Seems they are happy again so now we have it back the way it was supposed to work.

To add some cred to this, I can believe it as when I went for my first test drive in a C2S it was one of the very first of them in the country and the salesman was keen to demonstrate the quite violent gear changes when flooring it in Sport+ (with the PDK). When I got mine 9 months later it just did not feel that way at all - yes - there was still a bit of a "thump" when the gears got thown in but not the way I thought I remembered it. I put it down to me just having gotten used to the car. Well, it's certainly fixed and the way I remember it.

Rainier

Did you request the update from the CT dealership? The Joburg guys don't offer any information or pro-active advice regarding software updates. Is it something I should ask them to look at?

What was the date of the PDK update?

My May '13 release update did not make any difference in off the line hesitation - still the same from when new. (May '12 build)

In Sport+, the kick-in-your-ass upshifts seem less violent.

No I did not request anything. I took it for the 10.000Km oil service and they told me my car was marked for a "campain" to do with the PDK and engine control unit. The service manager could not tell me what the update was all about and that "most likely I would not notice any difference".
Well, boy was he wrong on that one. I felt the difference right away pulling out of the Porsche center !

I took delivery of the C2S in December 2012 and the update was done six weeks ago or so.

Rainier

Did you approach JHB with this? Dont feel like waiting for the service if this makes a diff!

I have not, because honestly I don't think my car suffers from the hesitation problem.

Bump

Add another 991S2 to the list of hesitation. I'll bring it up in 2 months when its annual is due.

I too have a hesitation mostly in 2nd gear acceleration (PDK) around 2500 rpm after startup. The car jerks forward and is very annoying. Called the dealer for the PDK update and asked them about this hesitation. They said that they have never heard of this before and the car needs to warm up for 3 minutes or 3 miles. Will see if the update will take care of this issue next week...

The first time I took my car in after Rainier talked about an update, my hesitation issue vanished. It's been quite some time now (as in months) and my car drives great. I punch it off the line all the time now and never worry about a delay.