Crown

Wonderbar:

Does the stop mechanism turn the engine off everytime you stop?  Stupid question, but could not find answer before...

In my experience it's a little more complicated than that.

First, the engine has to be warmed up before one would like to permit the start/stop to begin.  Cold engines are more temperamental (unpredictable?) than warm ones.

There also seems to be a small time delay after the car has stopped before the engine shuts down, called "leaving your foot on the brake pedal".  This prevents a "bucking" effect if one is continuously inching along in stop-and-go traffic using a nervous brake foot.

In my experience, the engine seems to shut down when it should and not when it shouldn't.  Apart from being a new experience, it seems just right to me.

--

Mike

2005 Carrera GT + 2008 Tesla Roadster +2010 Panamera Turbo + 2001 BMW Z8 + 1972 BMW 3.0 CSi +2009 Bentley Arnage T

Very helpful Mike and Aldo, thanks...

 Actually, I have this auto start&stop function in my M3. It works perfectly. When the engine stops you still have the radio. It doesn't change the setup ie if the DSC is off, when the car starts, it is still off. So you have to do nothing. Just release the brake and before you put your foot on the gas pedal the engine starts. Finally, it only works if the transmission is in "Auto/drive" mode. 

ONUR

11 M3 Coupe AW

09 Audi TTS Coupe - 07 997 Carrera S - 05 M3 Coupe - 03 M3 Coupe - 96 M3 Coupe EVO (PASS TIME HISTORY)

W8MM:

STRADALE:

.. Can't be very good for the engine or battery either...The AC continues to blow as hard if you're in 100F and stopped in traffic for a few minutes & your headlights don't dim???

In the Panamera and Cayenne, there is some sort of battery state-of-charge monitor that decides when the battery has "had enough".  If the battery-powered functions like AC compressor have drained too much charge, the engine re-starts before anything bad happens to the battery.

There is all sorts of "magic" going on behind the scenes to make the start/stop system ergonomically and technically successful.

Thanks Mike. Appreciate the answers.

I'm not familiar w/ battery technology, wouldn't this diminish battery life though, having to make thousands more starts? I would also think that it could actually lessen your gas mileage if you're in stop and go traffic where you're only stopping long enough for it to turn off, then turn back on, which revs the engine slightly using more gas then had you just stopped & idled.  

What happens w/ a stick shift car, if it wants to turn back on & you're in gear? Guess it wouldn't without clutch pressed...

Hmmmmm....Say you're on a really steep incline? If the car turns off w/ a stick shift seems like it could be a challenge. It already is now when someone in a truck pulls 6inches from your rear spoiler & you're stopped on a steep uphill. It's a quick maneuver with feathering the clutch w/ your left foot & a dance between the brake pedal & gas pedal w/ your right stopping the car from rolling backwards & that's when the car is running...... What's that going to feel like knowing you have to take your right foot off the brake to a gas pedal on a car that isn't running???    .. You'll need 3 feet.... I know you might not be familiar w/ all these questions, I'm sure Porsche has all this stuff figured out,  just curious/thinking out loud...

Maybe this all just a ploy to sell PDK...

 
--

08 PORSCHE Turbo Cabriolet - 06 Ferrari F430 - 04 Durango HEMI - 04 Harley Davidson Screamin Eagle - 93 Harley Davidson Nostalgia

Porsche-Jeck:

STRADALE:

Can't be very good for the engine or battery either...The AC continues to blow as hard if you're in 100F and stopped in traffic for a few minutes & your headlights don't dim???

Probably the system works the same as in the BMWs, meaning:

> it doesn't work as long as the engine is cold

> it doesn't work when it's too cold outside (energy needed for heating the cabin)

> it doesn't work when it's too hot outside (energy needed for cooling the cabin).

I bet the norm cycle for measuring mpg or L/100 km works with a nicely warmed up engine and perfect weather

http://www.thetruthaboutcars.com/2010/02/the-problem-with-start-stop-systems/

08 PORSCHE Turbo Cabriolet - 06 Ferrari F430 - 04 Durango HEMI - 04 Harley Davidson Screamin Eagle - 93 Harley Davidson Nostalgia

Wonderbar:

Porsche will be broadcasting the 991 press conference live via satellite from Frankfurt.  But from the press release it doesn't look like it will feed to the U.S.  Any ideas why?  Am I correct?

wonderbar, they will also broadcast it via internet. Starting from Sept 13 you will find more information on this page:

http://www.porsche.com/germany/sportandevents/autoshows/iaa-2011/ 

STRADALE:

I'm not familiar w/ battery technology, wouldn't this diminish battery life though, having to make thousands more starts? I would also think that it could actually lessen your gas mileage if you're in stop and go traffic where you're only stopping long enough for it to turn off, then turn back on, which revs the engine slightly using more gas then had you just stopped & idled.  

My Panamera has among the largest batteries I have ever seen in a passenger car.  It would seem to have plenty of capacity for heavy service.

Also, all the engineering work done on hybrid and purely electric vehicles has provided a technology base for taking care of automotive batteries and ensuring that they live a long and productive life.  When I wrote up-thread about a magic monitor that senses when the battery has "had enough" and relents of more demand, I was referring to all of the tricks and techniques for properly managing the battery to compensate for different temperatures, varying load demand, inferring the condition of internal chemistry, and the like.

Battery related technology has come a very long way recently.

Mike

2005 Carrera GT + 2008 Tesla Roadster +2010 Panamera Turbo + 2001 BMW Z8 + 1972 BMW 3.0 CSi +2009 Bentley Arnage T

W8MM:

STRADALE:

I'm not familiar w/ battery technology, wouldn't this diminish battery life though, having to make thousands more starts? I would also think that it could actually lessen your gas mileage if you're in stop and go traffic where you're only stopping long enough for it to turn off, then turn back on, which revs the engine slightly using more gas then had you just stopped & idled.  

My Panamera has among the largest batteries I have ever seen in a passenger car.  It would seem to have plenty of capacity for heavy service.

Also, all the engineering work done on hybrid and purely electric vehicles has provided a technology base for taking care of automotive batteries and ensuring that they live a long and productive life.  When I wrote up-thread about a magic monitor that senses when the battery has "had enough" and relents of more demand, I was referring to all of the tricks and techniques for properly managing the battery to compensate for different temperatures, varying load demand, inferring the condition of internal chemistry, and the like.

Battery related technology has come a very long way recently.

 Nope - the batteries are smaller then years ago a MB S-class had.

Last winter my Panamera after few days short driving at morning and evening had an empty battery. I had to call at 9 pm Porsche to come to help. In about on hour I had help in Ischgl (!!! superb service). The service guy told me that they have a lot of problems with Panamera, BMW 7-class and similar cars in winter. The batteries are to small. In the morning everyone drives the car with seat heating and after 15 minutes stops the car, no way the battery could charge enough.

AM
www.aldo-yachting.de

ALDO:

 Nope - the batteries are smaller then years ago a MB S-class had.

Last winter my Panamera after few days short driving at morning and evening had an empty battery. I had to call at 9 pm Porsche to come to help. In about on hour I had help in Ischgl (!!! superb service). The service guy told me that they have a lot of problems with Panamera, BMW 7-class and similar cars in winter. The batteries are to small. In the morning everyone drives the car with seat heating and after 15 minutes stops the car, no way the battery could charge enough.

Well, my battery looks pretty big to my eyes, but your MB S-class observation is noted.

My comments on battery size were directed to the start/stop function and when it is allowed to shut down and re-start the motor.  I can well believe there are other factors not to do with start/stop that can affect battery life.  Sounds like the alternator is too small if it can't keep up with electrical loads and recharge the battery at the same time.

--

Mike

2005 Carrera GT + 2008 Tesla Roadster +2010 Panamera Turbo + 2001 BMW Z8 + 1972 BMW 3.0 CSi +2009 Bentley Arnage T

Straying from the start/stop discussion for just a minute, the configurator on the South African website (including pricing for this market) has FINALLY become available.  I was pleasantly surprised to note that the base price for the 991 C2S is increasing by only 4.9% over that of the 997 C2S (from R1,080,000 to R1,133,000 - which, for perspective, equates to about $162k at the current exchange rate).  I'm sure the strength of the rand in recent times had a lot to do with the relatively small increase.  Of course, adding just a few "essential" options (sport exhaust, sport suspension, sport chrono package, etc, etc) very quickly takes this closer to the R1.4m ($200k) level.

What sent a chill up my spine, though, was the fact that the configurator would not allow me to deselect PDK - I got the following pop-up message: "Deselection of this option is not possible".  I suspect (hope) that this is just a temporary glitch in the configurator - but at the same time I can't help believing that this is probably a sign of things to come!  

PureBlue:

1) ...the configurator on the South African website (including pricing for this market) has FINALLY become available.  I was pleasantly surprised to note that the base price for the 991 C2S is increasing by only 4.9% over that of the 997 C2S (from R1,080,000 to R1,133,000) ...

2) What sent a chill up my spine, though, was the fact that the configurator would not allow me to deselect PDK...I suspect (hope) that this is just a temporary glitch in the configurator - but at the same time I can't help believing that this is probably a sign of things to come!  

1) I agree, not bad at all.  BTW Pureblue, I hear that our Century City friends are looking to drop their track day ban (albeit with strings attached)

2) The times they are a changin'...!

Come on guys, stop whining about stop/start:

1. You can switch it off.

2. It works.

I've driven cars with stop/start and whilst it takes a couple of hours to get used to it doing it, it's fine and simply doesn't affect how you drive. It's saves a little fuel and allows Porsche to get better ratings for fuel use. Would you rather they were forced to run lower power engines to get to the same required efficiency ratings?

So, with PDK, start/stop is engaged each time we use our brake to come to a complete stop?  Then if we creep forward in stop and go traffic, the engine will cut off each time?  Each time, the starter will kick in when we take our foot off the break.

If I'm on the 405 freeway in LA in rush hour, and everybody has start/stop, then it's gonna sound pretty funny when we hear everybody's engine starting up and stopping for the next hour....

2005 997S Blk/Blk

SoCal Alan:

So, with PDK, start/stop is engaged each time we use our brake to come to a complete stop?  Then if we creep forward in stop and go traffic, the engine will cut off each time?  Each time, the starter will kick in when we take our foot off the break.

If I'm on the 405 freeway in LA in rush hour, and everybody has start/stop, then it's gonna sound pretty funny when we hear everybody's engine starting up and stopping for the next hour....

There's a time delay so that inching along doesn't count as coming to a stop.  One has to hold the brake pedal down for a period of time before the system judges it should shut down the motor.  I've never had it be a big deal in any way in my Panamera Turbo w/PDK.

--

Mike

2005 Carrera GT + 2008 Tesla Roadster +2010 Panamera Turbo + 2001 BMW Z8 + 1972 BMW 3.0 CSi +2009 Bentley Arnage T

From Milanno Artworks:

pride355:

1) If you ever have to lift off the throttle in a corner, the car immediately starts to oversteer and this kind of oversteer, unlike throttle oversteer, is very dangerous. I always drive my cars DSC/PSM off unless it is raining. Once. I was fast into a corner and just in the middle of it, there was a car on my lane and I had to slow down so I lift off the throttle. Once I released the throttle, I had a sudden oversteer, I over corrected it and it went to other side. I countersteered to other side again. When I was just thinking that I'm loosing the back end completely, my lane had cleared and I just put my foot on the throttle and catched the back end. As soon as I regained the control, I checked the speedo and it was 155 km/h. It was the scariest moment I had in my 997. After 2 weeks from this incident, I wanted to try the same corner again. I was little aggrasive and quick with the steering wheel and never lift of the throttle. In the end my exit speed was above 170 km/h. So, 2 different scenario with huge speed difference. 

Well described, but this is the reason that I would tend to use PSM on the road (and turn it off on the track, if desired).  If you feel PSM is too intrusive on the road, then engaging Sport (with Sport Chrono option) will raise its threshold.  If you find this is still too intrusive for the road, then you might be driving a bit faster than is safe (not to judge - it's your choice).

73 Carrera RS 2.7 Carbon Fiber replica (1,890 lbs).  Former: 73 911S, Two 951S's, 996 C2, 993 C2, 98 Ferrari 550 Maranello

Budster:

 BTW Pureblue, I hear that our Century City friends are looking to drop their track day ban (albeit with strings attached).

Not exactly.  According to a recent letter received from PAG, tracking your car independently will still invalidate your 3-year maintenance plan, but they have decided to offer PSDS sessions in SA - so that you can safely enjoy your car on the track under the close supervision and watchful eye of a certified Porsche instructor. 

Thanks for the videos pjd!

Have you driven it w/ a stick cabriolet? After-market exhaust with it stalling & turning back on?? I enjoy having the cab & slightly better sound w/ the tubi but on a nice day driving with the top down think it would drive me mad having the engine turn -off & back on...  

You could "save fuel" without paying for gimmicks you don't want or need but are getting screwed for in the price... If you're driving like how Porsche 911's are designed/meant to be driven & "saving fuel" you may as well buy a prius and save lots... There's plenty of opportunities to "save fuel", they've already designed the car to be more fuel efficient without gimmicks,,, saving 1mpg or less by stalling every time you stop is pretty ridiculous (is the word that keeps coming to mind)  on a 523HP Twin Turbo sports car with big spoilers, gapping radiator vents & 325 tires...

RE: 2. - It "worked"/works just fine without it

I'm sorry with this one Porsche had a brain fart...

--

08 PORSCHE Turbo Cabriolet - 06 Ferrari F430 - 04 Durango HEMI - 04 Harley Davidson Screamin Eagle - 93 Harley Davidson Nostalgia

PureBlue:

What sent a chill up my spine, though, was the fact that the configurator would not allow me to deselect PDK - I got the following pop-up message: "Deselection of this option is not possible".  I suspect (hope) that this is just a temporary glitch in the configurator - but at the same time I can't help believing that this is probably a sign of things to come!  

 

I'm afraid Porsche is playing games with the PDK option. In the US configurator it appears if you want a manual C2 with LSD you're SOL, you have to check PDK. You can get a manual Boxster/Cayman with LSD, but not on a new 991 C2.

does anybody knows if the 991 uses a revised PDK  or its the same PDK of the 997.2 ???

SoCal Alan:

So, with PDK, start/stop is engaged each time we use our brake to come to a complete stop?  Then if we creep forward in stop and go traffic, the engine will cut off each time?  Each time, the starter will kick in when we take our foot off the break.

If I'm on the 405 freeway in LA in rush hour, and everybody has start/stop, then it's gonna sound pretty funny when we hear everybody's engine starting up and stopping for the next hour....

Right. I was thinking about it in below ground garages, closed in parking areas. You're stopped and waiting for someone to pull out when the car stalls... (Damn! Forgot to turn off the stalling thingy). No,  that won't sound strange, make you look like you can't drive. But maybe nobody's around to laugh at the weenie that can't drive his brand new 911.... We're already stereotyped, thanks Zuffenhausen...

--

08 PORSCHE Turbo Cabriolet - 06 Ferrari F430 - 04 Durango HEMI - 04 Harley Davidson Screamin Eagle - 93 Harley Davidson Nostalgia

 I suspect this will be a mandatory feature on all cars in the future. The fuel requirements are getting very difficult to meet. Porsche could have been at risk of reducing production to Ferrari levels  or bite the bullet and provide the feature on its cars.

Like all new features to meet regulations there will be initial resistance. Recall the anger directed toward CA emission laws (now nationwide), the Federal government seat belt requirements, mandatory safety glass and so on.

Today would any us of want to be behind a car that does not have a catalytic convertor or drive without fasten our seat belts? Would you buy a car which does not have safety glass? I don't think so.

Carrara:

Thanks for the videos pjd!

xandi911:

 

does anybody knows if the 991 uses a revised PDK  or its the same PDK of the 997.2 ???

It's fundamentally the same - perhaps a few tweaks and improved software.  But, the 991 GT3 is due to receive PDK-S with lighter weight and hopefully will have 7 real performance close ratios (not just a tacked on cruising 7th gear).

73 Carrera RS 2.7 Carbon Fiber replica (1,890 lbs).  Former: 73 911S, Two 951S's, 996 C2, 993 C2, 98 Ferrari 550 Maranello

 I think it would be cool if on the GT3 they offered a heavy duty sequential style shifter for the GT3 PDK. After all, the GT3 Cup's sequential is virtually clutchless. The only reason you have to engage the clutch on downshifts is for longevity. 

Carrara:

 I think it would be cool if on the GT3 they offered a heavy duty sequential style shifter for the GT3 PDK. After all, the GT3 Cup's sequential is virtually clutchless. The only reason you have to engage the clutch on downshifts is for longevity. 

But the sequential drives like crap even in the paddock, not to mention in traffic in a big city.

73 Carrera RS 2.7 Carbon Fiber replica (1,890 lbs).  Former: 73 911S, Two 951S's, 996 C2, 993 C2, 98 Ferrari 550 Maranello