Notices
Cayenne 955-957 2003-2010 Series I
Sponsored by:
Sponsored by:

Cayenne hesitation....learn to live with it

 
Old 08-17-2005, 04:13 PM
  #16  
ltc
Super Moderator
Needs More Cowbell

Lifetime Rennlist
Member
Thread Starter
 
Join Date: Mar 2002
Posts: 29,318
Post

rome,
There was a recent Panorama article (996TT Tip vs 6spd) by Walter Rohrl that had a very good description of the modern Tiptronic gearbox.

IIRC, there were something like 200 software 'patterns' algorithmically available to control the transmission in response to various inputs: temperature, rpm, ABS, eGas/throttle position, DRIVING habits (yes, really), etc.
Basically the Tiptronic will adapt its shift points in reponse to what it believes wil be current driving conditions based on past inputs.
The DME works in a similar fashion, although much more strictly controlled due to the nature of controlling an engine/ emissions, etc

Since PSM is tied into the DME and Tiptronic (via CAN bus), there will be different algorithms initially applied based on the car's 'understanding' that by disabling PSM, there will be 'spirited driving'; so the transmission may start out in D1 rather than D2, the eGas curves will be altered, etc....the end result being less perceived throttle hesitation lag (throw in turbo lag and spool ups just to further complicate engine management matters if you want to).
Now, if you drive long enough with PSM off, the Tiptronic control unit will begin to 'adapt' to this as your 'normal' driving........however, if you drive very conservatively, PSM on, trying to maximize fuel economy, you will end up with a different vehicle response.

Simple, huh?
ltc is offline  
Old 08-17-2005, 04:16 PM
  #17  
ltc
Super Moderator
Needs More Cowbell

Lifetime Rennlist
Member
Thread Starter
 
Join Date: Mar 2002
Posts: 29,318
Post

Originally Posted by mudman2
You don't need to be, its really something that is easy to live with, is it perfect ?, no, but what is ?, the "!"
Had to use the "!" didn't you.
Superman had Kryptonite, I get stuck with "!". Fine.

Originally Posted by mudman2
They did not have the ( ! )
That's it, keep poking the tiger with a pointed stick.....then when someone forgets to latch the door to the cage, DON'T blame the tiger.

Originally Posted by mudman2
Sorry rome a couple of in jokes may float over you for now.
True, but once he takes delivery, it will all of a sudden make sense.

P.S. NO, I'm NOT sharing my Purplesaurus Rex with the new guys......
ltc is offline  
Old 08-17-2005, 04:20 PM
  #18  
mudman2
Moderator !x2
Rennlist Member

 
mudman2's Avatar
 
Join Date: Jun 2003
Location: Southeastern PA
Posts: 5,981
Default

You crack me up !

:-)
mudman2 is offline  
Old 08-17-2005, 04:32 PM
  #19  
rome
Addict
Rennlist Member
 
rome's Avatar
 
Join Date: Aug 2005
Location: North Shore
Posts: 3,984
Default

Originally Posted by ltc
rome,
There was a recent Panorama article (996TT Tip vs 6spd) by Walter Rohrl that had a very good description of the modern Tiptronic gearbox.

IIRC, there were something like 200 software 'patterns' algorithmically available to control the transmission in response to various inputs: temperature, rpm, ABS, eGas/throttle position, DRIVING habits (yes, really), etc.
Basically the Tiptronic will adapt its shift points in reponse to what it believes wil be current driving conditions based on past inputs.
The DME works in a similar fashion, although much more strictly controlled due to the nature of controlling an engine/ emissions, etc

Since PSM is tied into the DME and Tiptronic (via CAN bus), there will be different algorithms initially applied based on the car's 'understanding' that by disabling PSM, there will be 'spirited driving'; so the transmission may start out in D1 rather than D2, the eGas curves will be altered, etc....the end result being less perceived throttle hesitation lag (throw in turbo lag and spool ups just to further complicate engine management matters if you want to).
Now, if you drive long enough with PSM off, the Tiptronic control unit will begin to 'adapt' to this as your 'normal' driving........however, if you drive very conservatively, PSM on, trying to maximize fuel economy, you will end up with a different vehicle response.

Simple, huh?
Whoa! Seems lilke a no-brainer to keep PSM off if it activates anyway when needed, and keeping it on lags performance and throttle response.

Is there any good reason to keep it "on" otherwise?
rome is offline  
Old 08-17-2005, 04:37 PM
  #20  
mudman2
Moderator !x2
Rennlist Member

 
mudman2's Avatar
 
Join Date: Jun 2003
Location: Southeastern PA
Posts: 5,981
Default

Well there is a reason, if your commuting, you will most certainly spill your coffee, the so called "lurch".

OK if its only you (you can drive home and change) but if your significant other is the passenger thats another issue.

Then the PSM on can give pretty smooth responses.
mudman2 is offline  
Old 08-17-2005, 05:30 PM
  #21  
RJay
Addict
Rennlist Member

 
RJay's Avatar
 
Join Date: Dec 2001
Location: MA
Posts: 1,010
Default

Originally Posted by ltc
rome,
There was a recent Panorama article (996TT Tip vs 6spd) by Walter Rohrl that had a very good description of the modern Tiptronic gearbox.

IIRC, there were something like 200 software 'patterns' algorithmically available to control the transmission in response to various inputs: temperature, rpm, ABS, eGas/throttle position, DRIVING habits (yes, really), etc.
Basically the Tiptronic will adapt its shift points in reponse to what it believes wil be current driving conditions based on past inputs.
The DME works in a similar fashion, although much more strictly controlled due to the nature of controlling an engine/ emissions, etc

Since PSM is tied into the DME and Tiptronic (via CAN bus), there will be different algorithms initially applied based on the car's 'understanding' that by disabling PSM, there will be 'spirited driving'; so the transmission may start out in D1 rather than D2, the eGas curves will be altered, etc....the end result being less perceived throttle hesitation lag (throw in turbo lag and spool ups just to further complicate engine management matters if you want to).
Now, if you drive long enough with PSM off, the Tiptronic control unit will begin to 'adapt' to this as your 'normal' driving........however, if you drive very conservatively, PSM on, trying to maximize fuel economy, you will end up with a different vehicle response.

Simple, huh?
Hmmm... so what the heck happens when you add a trailer into the mix? I'm think of getting one as a tow vehicle, does this exacerbate the problem?
RJay is offline  
Old 08-17-2005, 05:32 PM
  #22  
mudman2
Moderator !x2
Rennlist Member

 
mudman2's Avatar
 
Join Date: Jun 2003
Location: Southeastern PA
Posts: 5,981
Default

No you basically drive in manual mode with the trailer and keep it out of 6 for the most part.
mudman2 is offline  
Old 08-17-2005, 05:58 PM
  #23  
thecleaner
User
 
thecleaner's Avatar
 
Join Date: Jan 2005
Location: St. Augustine, Fl
Posts: 169
Default

Quote
"Hmmm... so what the heck happens when you add a trailer into the mix? I'm think of getting one as a tow vehicle, does this exacerbate the problem?"

Nothing to the response but you will see !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, Just ask Lewis.
Pass the kool-aid
thecleaner is offline  
Old 08-17-2005, 06:09 PM
  #24  
mudman2
Moderator !x2
Rennlist Member

 
mudman2's Avatar
 
Join Date: Jun 2003
Location: Southeastern PA
Posts: 5,981
Default

Come on Lance ! thats baiting the monster !!!
mudman2 is offline  
Old 08-17-2005, 06:15 PM
  #25  
thecleaner
User
 
thecleaner's Avatar
 
Join Date: Jan 2005
Location: St. Augustine, Fl
Posts: 169
Default

I can hear the growls down here!
thecleaner is offline  
Old 08-17-2005, 06:23 PM
  #26  
skl
Official Wednesday AM Red Bull F1 test driver
Rennlist Member
 
skl's Avatar
 
Join Date: Apr 2003
Location: North Scottsdale 3/4, Des Moines 1/4
Posts: 7,766
Default

Yes, if towing you should be in manual mode. I rarely hit 6th when towing. Maybe on level ground or downhill. Lewis and I both wonder if anyone towing with an enclosed car trailer can get it to work the lights without the famous ! and the "check trailer lights" message????? I could only get it to work properly with a small single axle enclosed go-kart trailer...
skl is offline  
Old 08-17-2005, 06:27 PM
  #27  
RJay
Addict
Rennlist Member

 
RJay's Avatar
 
Join Date: Dec 2001
Location: MA
Posts: 1,010
Default

Originally Posted by thecleaner
Quote
"Hmmm... so what the heck happens when you add a trailer into the mix? I'm think of getting one as a tow vehicle, does this exacerbate the problem?"

Nothing to the response but you will see !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, Just ask Lewis.
Pass the kool-aid
I'm afraid to ask...
RJay is offline  
Old 08-17-2005, 06:45 PM
  #28  
MadFox
Pepper Bartender
Rennlist Member
 
MadFox's Avatar
 
Join Date: Jan 2005
Location: Alabama USA
Posts: 2,227
Default

Originally Posted by mudman2
You crack me up ! :-)
Ditto, Mudman2.. LTC is on a roll. He must have spiked the Kool-Aid per his post on "spiced coolant" .... the last few posts are some of his best humor filled good info yet.. Darn it.. I'm not at home where I can get to the Cayenne humor liquid stuff and "be LTC happy", too!! (whoops !! unintentionally... wait, maybe Lewis can handle the !!! whilest sipping PurplesaurusRex? .. funny stuff... !!!!!!!! (okay, just want to see if the happy juice will keep biting sarcasm from emerging!!!!!!!!!!!!!!
MadFox is offline  
Old 08-17-2005, 07:13 PM
  #29  
rockitman
Super User
 
rockitman's Avatar
 
Join Date: Jul 2003
Location: Got Revs ???
Posts: 5,739
Default

hmmm, hesitation ? Don't have that. Ocassional vibration with 20's yes. Choice between the two Cayenne driving characteristics(LOL)..I will take the "good" vibrations....
rockitman is offline  
Old 08-17-2005, 08:10 PM
  #30  
mudman2
Moderator !x2
Rennlist Member

 
mudman2's Avatar
 
Join Date: Jun 2003
Location: Southeastern PA
Posts: 5,981
Default

Hey Chris long time no hear !
mudman2 is offline  

Thread Tools
Search this Thread
Quick Reply: Cayenne hesitation....learn to live with it


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: