Notices
991
Sponsored by:

slight hesitation on accel at 3k rpm (991 base, MT)

 
Old 03-21-2013, 01:28 PM
  #16  
mtony
User
 
mtony's Avatar
 
Join Date: Jun 2012
Location: ATL
Posts: 478
Default

Having this same issue with my '13 911S with PDK. Has anyone been able to get this resolved. It's really taking the driving pleasure away from my new car. Seems like all I do is try to feel it every time I got through the 2,600 to 3,000 RPM range. It's most noticeable in first and second gear, but occasionally I feel it in third gear also.
mtony is online now  
Old 03-21-2013, 02:51 PM
  #17  
Carrera GT
Wordsmith
Rennlist Member
 
Carrera GT's Avatar
 
Join Date: Feb 2003
Posts: 8,612
Default

Originally Posted by mtony View Post
Having this same issue with my '13 911S with PDK. Has anyone been able to get this resolved. It's really taking the driving pleasure away from my new car. Seems like all I do is try to feel it every time I got through the 2,600 to 3,000 RPM range. It's most noticeable in first and second gear, but occasionally I feel it in third gear also.
There seems to be much the same thing my 991S w/PDK.

I'd characterize it as a "dead" throttle tip-in. There's a delay when going from a closed throttle through the first millimeters of travel of the pedal, then the engine appears to pick up revs smoothly and then respond directly to the throttle pedal position. It's as if the electronics have some programming in that transition to compensate for driveline "shunt" and to smooth the transition from coasting to acceleration.

I've tried all kinds of combinations and permutations to convince the car to give immediate throttle response at tip-in but I've not found any useful solution.

It seems to be less pronounced when the car is driven vigorously or switched to Sport Plus.

I've asked the service manager about any updates as recently as two weeks ago and there's none.
Carrera GT is offline  
Old 03-21-2013, 03:09 PM
  #18  
mtony
User
 
mtony's Avatar
 
Join Date: Jun 2012
Location: ATL
Posts: 478
Default

Originally Posted by Carrera GT View Post
There seems to be much the same thing my 991S w/PDK.

I'd characterize it as a "dead" throttle tip-in. There's a delay when going from a closed throttle through the first millimeters of travel of the pedal, then the engine appears to pick up revs smoothly and then respond directly to the throttle pedal position. It's as if the electronics have some programming in that transition to compensate for driveline "shunt" and to smooth the transition from coasting to acceleration.

I've tried all kinds of combinations and permutations to convince the car to give immediate throttle response at tip-in but I've not found any useful solution.

It seems to be less pronounced when the car is driven vigorously or switched to Sport Plus.

I've asked the service manager about any updates as recently as two weeks ago and there's none.
Our issue is not related to throttle tip-in. It's always at the same RPMS and not necessarily from a stand still.
mtony is online now  
Old 03-21-2013, 04:05 PM
  #19  
Carrera GT
Wordsmith
Rennlist Member
 
Carrera GT's Avatar
 
Join Date: Feb 2003
Posts: 8,612
Default

Originally Posted by mtony View Post
Our issue is not related to throttle tip-in. It's always at the same RPMS and not necessarily from a stand still.
The hesitation at mid-range has been associated (rightly or wrongly) with variocams. The tip-in is more to do with software and who knows the motivation behind the compromise. Maybe it's emissions, maybe it's "drivability." Whatever the case, it would be great to have yet another button to turn off any expendable software and let the throttle have an analog, long travel feel. Ironically -- and I know I'm going off the end of a dead topic -- Porsche continues with this idea of "quickening" the throttle for Sport Plus but the conventional wisdom is to have a "slow" throttle to allow a skilled driver to have finer control over the throttle position. As ever, the marketing voice is louder than the enthusiast driver.
Carrera GT is offline  
Old 03-22-2013, 06:26 PM
  #20  
jmct
User
 
jmct's Avatar
 
Join Date: Dec 2012
Location: Connecticut
Posts: 132
Default

I had this on my 997.1 and notice it on my 991 C4S which I have had for two weeks. It is very noticeable to me, slightly more when cold.

On my 997.1, I took it to the dealer a few times and they said it was the variable cam adjustment that takes place at around 2,800/2,900 RPMs. The reason I took it in more than once is I couldn't believe it was that noticeable and was convinced it was a defect with the engine, eventually accepting their explanation. I had hoped it would be improved on my 991 but after driving it, I think it is about the same.

I'm a little surprised that Porsche hasn't done a better job with their variable cam system. I accept it as a somewhat weak feature of an otherwise great car.
jmct is offline  
Old 03-22-2013, 06:43 PM
  #21  
mtony
User
 
mtony's Avatar
 
Join Date: Jun 2012
Location: ATL
Posts: 478
Default

Interestingly enough, I can't feel it when accelerating through the 2600-3000 RPM range in neutral. Seems to only happen under load. I sometimes wonder if it could be some strange behavior form the PDK. Does anyone notice this with the manual transmission?
mtony is online now  
Old 03-22-2013, 07:52 PM
  #22  
dodo1porsche
User
 
Join Date: Apr 2011
Posts: 18
Default

It is very noticed on my 997.2 manual.
I cannot feel it on my Boxster S PDK.
So this cam lift is not noticeable on all engines. Some are very very difficult to notice.
The smoother one tries to drive the the more noticeable it will be. If I press the gas a bit harder in the lower RPM, you get the lift early and you won't notice anything the 2600-3000 range. inconveniece it remains.
dodo1porsche is offline  
Old 03-24-2013, 12:36 AM
  #23  
cmb13
User
 
cmb13's Avatar
 
Join Date: Dec 2009
Location: South Florida
Posts: 451
Default

I notice it on my new 991 MT. It feels like the power doesn't kick in until over 3000 rpms. I just thought it was a lack of low end torque. It does bother me, I must say. My 335i, which was a turbo, had a smoother torque curve than this car; the 991, even though it's NA, feels more like a turbo with lag.

I wonder if it can be programmed out.
cmb13 is offline  
Old 06-15-2013, 03:46 AM
  #24  
Mr.Boon
User
 
Join Date: Apr 2013
Posts: 25
Default

Same issue here, 2014 991 4S with PDK (got it 1 day). Only done 150km so far and I've already spotted this as an annoyance Sad to hear nobody has been able to get it fixed.
Mr.Boon is offline  
Old 06-15-2013, 01:45 PM
  #25  
Carrera GT
Wordsmith
Rennlist Member
 
Carrera GT's Avatar
 
Join Date: Feb 2003
Posts: 8,612
Default

Originally Posted by Mr.Boon View Post
Same issue here, 2014 991 4S with PDK (got it 1 day). Only done 150km so far and I've already spotted this as an annoyance Sad to hear nobody has been able to get it fixed.
My 2012 991S w/PDK just showed up on a factory update bulletin. You might get your dealer to check the VIN of your car to see if there's an update. Probably unrelated, but when they say "PDK" that could well mean engine management, since the engine and trans are so tightly integrated in software. I'm not too concerned about whatever the update does because the current throttle and steering software could only be improved.

Here's hoping they roll out the GT3 steering software asap. I'm beginning to really dislike driving software.
Carrera GT is offline  
Old 06-15-2013, 03:32 PM
  #26  
mtony
User
 
mtony's Avatar
 
Join Date: Jun 2012
Location: ATL
Posts: 478
Default

Originally Posted by Carrera GT View Post
My 2012 991S w/PDK just showed up on a factory update bulletin. You might get your dealer to check the VIN of your car to see if there's an update. Probably unrelated, but when they say "PDK" that could well mean engine management, since the engine and trans are so tightly integrated in software. I'm not too concerned about whatever the update does because the current throttle and steering software could only be improved.

Here's hoping they roll out the GT3 steering software asap. I'm beginning to really dislike driving software.
I recently had the PDK service bulletin performed on my car, but it didn't improve the hesitation at all.
mtony is online now  
Old 06-16-2013, 04:27 AM
  #27  
Mr.Boon
User
 
Join Date: Apr 2013
Posts: 25
Default

I have done a lot of research online, a lot of people have it, but not everybody. But for the people who have it, I have seen 0 who got it fixed. And many have gone to Porsche, but the local tech's just haven't got a clue what it might be.
Mr.Boon is offline  
Old 06-19-2013, 03:05 PM
  #28  
MJBird993
User
 
MJBird993's Avatar
 
Join Date: May 2002
Location: Beautiful North Carolina
Posts: 1,985
Default

FWIW, I noticed the same thing - the variocam phasing - on my 996.2, and it was a big part of the rationale for selling it. On my 997.2 I never noticed it at all. Both were MT.
MJBird993 is offline  
Old 07-26-2013, 04:14 PM
  #29  
Bocatrip
User
 
Join Date: Jul 2013
Location: Fl USA
Posts: 13
Default

Originally Posted by Mr.Boon View Post
I have done a lot of research online, a lot of people have it, but not everybody. But for the people who have it, I have seen 0 who got it fixed. And many have gone to Porsche, but the local tech's just haven't got a clue what it might be.
There have been many posts with the Base 981 hesitation from a dead stop on the 981 forums. It seems to be an issue with the base 981 with PDK. The 981 S owners do not have any issues. My test drive of a base 981 PDK came up with the same symptoms. Intermittently at a stop, when trying to accelerate either aggressively or easy, I can a huge dead spot where the car does nothing and then takes off. This very issue is keeping me from purchasing a new base Cayman. Why can't Porsche get it corrected? One owner mentioned that when he first purchased his car it was fine, and after he took it to Porsche for an update the symptoms began. Too bad, but I'm waiting for a fix.
Bocatrip is offline  
Old 03-25-2014, 08:25 PM
  #30  
MMK110464
User
 
MMK110464's Avatar
 
Join Date: Jun 2005
Posts: 160
Default

I have a 2012 997.2 C4S and it has been doing the stumbling/hesitation at around 3k rpm since I bought it.

The simple procedure outlined below has eliminated the problem for me almost completely.

As you all know, the car starts the auto idle procedure when its been parked for several hours (which is usually the case in the morning when the car is started for the first time that day) and the revs go to approximately 1,500 rpm for about 1 minute. When this happens, I immediately blip the gas and take the revs to between 3-4k rpm. This will deactivate the auto idle and the revs will fall to its normal level of 800-850.

Thats it. This procedure will keep your car stumble free as long as the auto idle is not allowed to engage.

Please give a try and give your feedback

Last edited by MMK110464; 03-30-2014 at 12:07 PM.
MMK110464 is offline  

Thread Tools
Search this Thread
Quick Reply: slight hesitation on accel at 3k rpm (991 base, MT)


Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: