AWD Carrera 4 S
Discussion
ks 
I have to admit to jumping in with both feet here; assuming the OP was talking about the C4 systems fitted to 996 and gen1 997's - a pure mechanical system with no electronic intervention aside from the passive effects of brake modulation via PSM......
Well, always one to offer my head above the parapet; I looked into the Service Intro's from Porsche. The PTM system is adopted from the MY07 997 turbo (carried over unchanged); I checked the wiring diagrams for the Gen2 997C4 and there is no physical connection between the handbrake switch and the PTM ecu - though there is a digital CAN bus link for relevant system information. The instrument cluster has a handbrake switch input (for display) and this 'could' be put on the CAN bus via the cluster for consideration by other units.
The PTM system (the electromechanical clutch system linking the front axle and transmission) definition:
Porsche Traction Management is made up of the following systems:
PTM assists in finding total traction, for the fastest getaway from a standstill. In association with Sport Plus and Launch Control on the PDK the systems conspire to fire the car down the road in a way not far removed from being strapped to an exocet missile. The system is only active when 'slip' is detected between the front and rear wheels, depending on but not limited to steering input/accelerator position; in normal driving it is not 'active'. Unless the driver wants to do burnouts or play the silly fecker what purpose would disabling the front axle serve? The weight of the components, the drag from their connection and the 'dynamic feel' of such will still be evident. I presume there is a sense that the lack of drive to the front axle would give a different driving experience, there will be the "it's a purer drive" comment coming up I'm sure. In that case buy a C2 - you wont have to drive everywhere with the instrument cluster beeping and flashing at you.
I am intrigued from a geeky, want to know perspective but not sure if it would benefit the car if it is correct?!
Apologies for the long post
Well, always one to offer my head above the parapet; I looked into the Service Intro's from Porsche. The PTM system is adopted from the MY07 997 turbo (carried over unchanged); I checked the wiring diagrams for the Gen2 997C4 and there is no physical connection between the handbrake switch and the PTM ecu - though there is a digital CAN bus link for relevant system information. The instrument cluster has a handbrake switch input (for display) and this 'could' be put on the CAN bus via the cluster for consideration by other units.
The PTM system (the electromechanical clutch system linking the front axle and transmission) definition:
Porsche Traction Management is made up of the following systems:
- Full-time all-wheel drive with electronically controlled centre-differential lock for torque distribution between the front and rear axles
- Automatic Brake Differential (ABD) for traction improvement
- Anti-Slip Regulation (ASR) for slip control during acceleration and improved driving stability
PTM assists in finding total traction, for the fastest getaway from a standstill. In association with Sport Plus and Launch Control on the PDK the systems conspire to fire the car down the road in a way not far removed from being strapped to an exocet missile. The system is only active when 'slip' is detected between the front and rear wheels, depending on but not limited to steering input/accelerator position; in normal driving it is not 'active'. Unless the driver wants to do burnouts or play the silly fecker what purpose would disabling the front axle serve? The weight of the components, the drag from their connection and the 'dynamic feel' of such will still be evident. I presume there is a sense that the lack of drive to the front axle would give a different driving experience, there will be the "it's a purer drive" comment coming up I'm sure. In that case buy a C2 - you wont have to drive everywhere with the instrument cluster beeping and flashing at you.
I am intrigued from a geeky, want to know perspective but not sure if it would benefit the car if it is correct?!
Apologies for the long post
Bringing this back to life now I have a vested interest.
May also be worth mentioning that one of the guys at Silverstone demonstrated this feature in a 4 GTS during a driving experience day. That was a manual car, fwiw. Wife said it felt completely different on the ice hill.
If we get a bit of snow I might be able to test it.
May also be worth mentioning that one of the guys at Silverstone demonstrated this feature in a 4 GTS during a driving experience day. That was a manual car, fwiw. Wife said it felt completely different on the ice hill.
If we get a bit of snow I might be able to test it.
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