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Paddle shifter question?

PostPosted: Thu Oct 20, 2011 2:47 pm
by Jad
Does anyone know if anything can be done to help protect the transmission and engine in a paddle shift car in a spin? Normal manuals you put the clutch in, in automatics, the fluids can generally protect things, but what about the PDK style transmissions?

Re: Paddle shifter question?

PostPosted: Thu Oct 20, 2011 3:54 pm
by Greg Phillips
Interesting question. :?:

Wonder if the brains are in charge and know when to disengage the clutch in combination with the stability control???
Sounds like some fun testing under warranties :roflmao:

Greg

Re: Paddle shifter question?

PostPosted: Thu Oct 20, 2011 4:15 pm
by c4s4pcs
It seems that if you press firmly on the brake pedal (one foot in?), you should be able to lock up the drive train (as long as you aren't left foot braking while still right foot gassing...).

Re: Paddle shifter question?

PostPosted: Thu Oct 20, 2011 7:41 pm
by Jad
I assume ABS will unfortunately prevent lockup in most situations. Once you hit dirt, most traction control and ABS gets really confused, so I would hate to rely on that to save my car :surr:

Just hoping for some insight :roll:

Re: Paddle shifter question?

PostPosted: Thu Oct 20, 2011 8:24 pm
by c4s4pcs
Really, a very interesting question. One could "assume" that any reasonably smart system would disconnect thrust under the conditions of maximum braking and zero throttle - and I would propose that the Porsche system is more than reasonably smart. I think that the question is, under what conditions is the motive force interrupted? Obviously, at a stop, the clutches are disengaged - but what constitutes a "stop" to the PDK? I still think that a right foot shift from throttle to brake will cure all, but if left foot braking is employed, YMMV. It will be interesting to see what more knowledgeable people weigh in with.

Phil

Re: Paddle shifter question?

PostPosted: Thu Oct 20, 2011 11:06 pm
by Ted Myrus
Sounds like a "Tech Tactics West" puzzler. :idea:

Re: Paddle shifter question?

PostPosted: Fri Oct 21, 2011 9:26 am
by ttweed
Greg Phillips wrote:Wonder if the brains are in charge and know when to disengage the clutch in combination with the stability control???

I think this is the correct answer. From what I have read about the PDK, the software controls it based on many inputs.
The control unit receives information about the driver request, which includes the following:
• Selector-lever position
• Sport button and/or Sport Plus button
• Accelerator pedal position
• Brake signal
In addition, the operating state of the vehicle is also included:
• Wheel speeds
• Vehicle speed
• Road resistance
• Axial and lateral acceleration
• Altitude factor
• Engine and transmission speed
• Engine and transmission temperature
These input values are processed in the driving software and the driver request is executed, depending on the shift program and driver type detection.


I think the "axial and lateral acceleration" inputs will tell the transmission to "declutch" in a spin and no damage will be possible. There are many folks racing and autocrossing their PDK cars, spinnning them repeatedly, and reporting on forums that the engine does not stall, and no damage results to either the transaxle or engine. No worries, Jad. The Porsche engineering magic will save your equipment (unless, of course, you spin into something hard!)

TT

Re: Paddle shifter question?

PostPosted: Sun Oct 23, 2011 7:59 am
by Tawfik
Jad: On some paddle shifter cars (AMG, Ferrari, Lambo), keeping both paddles pulled in toward the driver for disengages the transmission just like a clutch. I don t know f the PDK does the same thing.

Re: Paddle shifter question?

PostPosted: Sun Oct 23, 2011 1:01 pm
by Jad
Thanks!

We made it through what looks to be the final DE school of the year without any incidents!!! I am not aware of any PDK type cars that spun to test their systems. The non-Porsche cars worried me more as Porsche's and spins have a long long long history together :lol: Other manufactures try to avoid spins, not just consider it a feature :P

Thanks to everyone that helped make the school a safe and successful program all year :beerchug:

Re: Paddle shifter question?

PostPosted: Sun Oct 23, 2011 1:05 pm
by Jad
Tawfik wrote:Jad: On some paddle shifter cars (AMG, Ferrari, Lambo), keeping both paddles pulled in toward the driver for disengages the transmission just like a clutch. I don t know f the PDK does the same thing.


I would love to see how many hands it takes to hold in both paddles, which may or may not move with the wheel, while frantically steering a spinning car to regain control  :bowdown: (Of course you also have to keep your hands off the wheel so you don't break your fingers if you do hit something! Quite a trick! :bowdown: )

Re: Paddle shifter question?

PostPosted: Wed Nov 02, 2011 3:03 pm
by smokin TT
Here is a little bit of experiance......not sure if it applies to the paddle shifter question. I have owned a 2007 C4S and 2009 Turbo with sport chrono and tiptronic with the steering wheel mounted thumb shifters.

On several occasions (both models) Autocrossing at El Toro and once at SOW I have been able to "kill" the car by spinning, or braking, downshifting and accelerating at the same time. I would think the simultaneous event of downshifting and acceleration might cause that but told by Porsche....not so. Curiously, the engine is on but the car will not engage into gear. Through trial and error, I figured out to "reboot the car" by turning off the engine and restarting the car.

So, maybe the car protects itself by disengaging the driveline electronically when sensing an event of significant control loss.

For what its worth.

Cheers,

Re: Paddle shifter question?

PostPosted: Sat Nov 12, 2011 11:24 pm
by tb911
I asked the question at Tech Tactics today

Was told the PDK disconnects whenever it thinks you are trying to stop -- as in, hard on the brakes. So "both feet in" is still good advice with a PDK -- can't hurt anything.