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What is the 7-speed manual gearbox?

 
Old 03-22-2013, 03:58 PM
  #46  
Carrera GT
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Originally Posted by GTgears View Post
It is hydraulically actuated. There's very clear pictures and I have just posted a partial of the written description. It is section 3, titled Power Transmission from the 991 Carrera/CarreraS technical documents. They go into some detail about how it is actuated and about the sensor that feeds back to the TCU telling the Electronic Pressure Adjuster (aka EDS7) when to apply force.

It is not an electric motor. It is actually a line that pressurizes the Cup Spring and pushes it inboard toward the 8 pins, which in turn clamp down on the clutch pack. There is even a thrust washer between the Cup Spring and 8 pins to deal with the fact that the LSD assembly is spinning, but the Cup Spring is not.

By "in use" I mean that I found a reference to PTV+ that said it was new for the 991 Carrera but was previously employed on the previous (997.2) turbo models.
I'd love to get my eyeballs on that doc. I'll go bug the service manager to order a set "for the shop."

So many questions! But I won't impose on you further, thanks for the follow-up.
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Old 03-22-2013, 04:03 PM
  #47  
Mike in CA
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Originally Posted by GTgears View Post
OK, I did my homework and have the factory tech documents. This adjustable LSD is a reality. I have seen the skematics. Here's an exerpt of their description of actuation of the LSD:

"Depending on the pressure applied in the pressure duct, the thrust washer is pressed onto the disk pack via 8 pressure pins and in this way achieve a locking value dependent on the pressure. This value is absolutely variable from 0 to 100%"

And

"An additional hydraulic control block is installed in the transmission for supplying oil pressure to the controlled rear differential lock..."

Furthermore, I have found reference to suggest that in addition to the 991 Carrera S PDK, this system is already in use on the turbo PDK vehicles.

Regards,

Matt
Thanks, Matt. Nice! I would imagine hydraulic actuation is faster reacting than an electric motor.
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Old 03-22-2013, 04:09 PM
  #48  
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Originally Posted by Carrera GT View Post
I'd love to get my eyeballs on that doc. I'll go bug the service manager to order a set "for the shop."

So many questions! But I won't impose on you further, thanks for the follow-up.
It's a shame your PM box is full...
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