Clutch Slipping or ??
#16
01-31-2012, 06:08 PM
512bb - thanks for the reply. Is there any way you can avoid this "bog"? Should I try launching at higher RPM? I try to slightly slip the clutch as opposed to dropping it and I always get this slight bog.
#17
01-31-2012, 08:25 PM
You can definitely slip the clutch a bit to reduce/eliminate the bogging, but beware that you are accelerating a lot of mass in a car that has a lot of traction. Fast acceleration from a standstill requires a balance of slip and traction. If the tires do not slip then the clutch should slip.
As an example if you look at top fuel cars (where the clutch is ON or OFF) the slip is taken by the tires and they deform at take off, like ringing a towel.
Again on the Turbo, given the level of traction the engine/flywheel momentum "jolts" the car to get off the line, but then there is a momentum loss which bogs the car. This is the time to slip the clutch a bit or take off at a higher RPM (higher RPMs though puts a lot of stress through the whole drive train).
On the all wheel drive PDK equipped cars I am willing to bet that launch control routes a bit more power through the front wheels during the first part of the take off. That is one of the only realistic ways I can come up with given the brutal off the line take off and lack of noticeable bogging from those cars.
Hope this helps. I am in Northern Jersey myself and it looks like there are a bunch of nice cars in the area. Let me know how it goes.
As an example if you look at top fuel cars (where the clutch is ON or OFF) the slip is taken by the tires and they deform at take off, like ringing a towel.
Again on the Turbo, given the level of traction the engine/flywheel momentum "jolts" the car to get off the line, but then there is a momentum loss which bogs the car. This is the time to slip the clutch a bit or take off at a higher RPM (higher RPMs though puts a lot of stress through the whole drive train).
On the all wheel drive PDK equipped cars I am willing to bet that launch control routes a bit more power through the front wheels during the first part of the take off. That is one of the only realistic ways I can come up with given the brutal off the line take off and lack of noticeable bogging from those cars.
Hope this helps. I am in Northern Jersey myself and it looks like there are a bunch of nice cars in the area. Let me know how it goes.
#18
01-31-2012, 09:42 PM
Doesn't sound like it was a clutch slip -- unless RPMs went up and the car didn't accelerate. Also, could the car have popped out of 2nd gear into neutral on you? If it is the clutch, I don't believe CPO would cover (even if you just bought the car). It looks like there's a pretty strict list on what CPO covers and doesn't cover (and the clutch is certainly not on that list). On the other hand, if you just bought the car, the dealer and/or Porsche could agree to a "good will" repair if they so choose. Good luck!
#19
01-31-2012, 10:16 PM
Join Date: Jul 2005
Location: Pacifica, Land of Fog
Posts: 123
Rep Power: 24 
I really don't think its the clutch, based on the test today. You know, I'm just going to drive the darn thing, enjoy the hell out of it, learn to be a better driver, and really get my $ worth. The last person paid $40K to drive the car 10k miles...I'll be damned if I am going to pay $4 a mile....I intend to enjoy the depreciation of this car! 
#20
02-01-2012, 07:02 AM
Here is a video of my clutch slipping on the track, it might help.
http://www.youtube.com/embed/SkkRT-SRxE0
http://www.youtube.com/embed/SkkRT-SRxE0
#21
02-01-2012, 07:18 AM
Thanks again and that makes perfect sense. I think I just need to learn to drive this car coming from rwd vehicles. Sadly I just moved to Chicago from Ridgewood area in NJ. Loved to meet up some 997tt folks here but haven't seen too many here so for some reason.
You can definitely slip the clutch a bit to reduce/eliminate the bogging, but beware that you are accelerating a lot of mass in a car that has a lot of traction. Fast acceleration from a standstill requires a balance of slip and traction. If the tires do not slip then the clutch should slip.
As an example if you look at top fuel cars (where the clutch is ON or OFF) the slip is taken by the tires and they deform at take off, like ringing a towel.
Again on the Turbo, given the level of traction the engine/flywheel momentum "jolts" the car to get off the line, but then there is a momentum loss which bogs the car. This is the time to slip the clutch a bit or take off at a higher RPM (higher RPMs though puts a lot of stress through the whole drive train).
On the all wheel drive PDK equipped cars I am willing to bet that launch control routes a bit more power through the front wheels during the first part of the take off. That is one of the only realistic ways I can come up with given the brutal off the line take off and lack of noticeable bogging from those cars.
Hope this helps. I am in Northern Jersey myself and it looks like there are a bunch of nice cars in the area. Let me know how it goes.
As an example if you look at top fuel cars (where the clutch is ON or OFF) the slip is taken by the tires and they deform at take off, like ringing a towel.
Again on the Turbo, given the level of traction the engine/flywheel momentum "jolts" the car to get off the line, but then there is a momentum loss which bogs the car. This is the time to slip the clutch a bit or take off at a higher RPM (higher RPMs though puts a lot of stress through the whole drive train).
On the all wheel drive PDK equipped cars I am willing to bet that launch control routes a bit more power through the front wheels during the first part of the take off. That is one of the only realistic ways I can come up with given the brutal off the line take off and lack of noticeable bogging from those cars.
Hope this helps. I am in Northern Jersey myself and it looks like there are a bunch of nice cars in the area. Let me know how it goes.
#22
02-01-2012, 10:24 PM
Join Date: Jul 2005
Location: Pacifica, Land of Fog
Posts: 123
Rep Power: 24 Here is a video of my clutch slipping on the track, it might help.
http://www.youtube.com/embed/SkkRT-SRxE0
http://www.youtube.com/embed/SkkRT-SRxE0
Hmmm...kind of sounded like that. We shall see...
Thread
Thread Starter
Forum
Replies
Last Post
ECS Tuning - BMW
Mini Cooper Vendor Classifieds
0
09-16-2015 03:02 PM
ECS Tuning - VW
VW Vendor Classifieds
0
09-09-2015 03:11 PM
