PDCC
#47
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There is no indication whatsoever that the rollbar is different for PDCC. Nor does it have to be. With PDCC when driving in a straight line the rollbar is effectively uncoupled from the wheel carrier. This is what offers a more-compliant ride on rough surfaces. When one wheel gets hammerd there's no copy effect.
#48
There is no indication whatsoever that the rollbar is different for PDCC. Nor does it have to be. With PDCC when driving in a straight line the rollbar is effectively uncoupled from the wheel carrier. This is what offers a more-compliant ride on rough surfaces. When one wheel gets hammerd there's no copy effect.
#49
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#50
Okay, well if that's what happens then Houston, we've got a problem.
Because the entire PDCC range of motion is only about 2". I forget the exact number from the Elephant Racing article but people can go look it up if they don't believe me. So the car hits a bump bigger than whatever that is and … CLANK! PDCC bottoms out. Back to the guessing board…. there's a decoupling valve… there's a rubbery reservoir… they use special compressible fluid… for our American customers we must say….
But these are all What About Bob baby steps. Our ultimate destination down this road is active suspension technology. Which nobody has. Not even Porsche. Which if they did, they sure would not waste on PDCC.
Because the entire PDCC range of motion is only about 2". I forget the exact number from the Elephant Racing article but people can go look it up if they don't believe me. So the car hits a bump bigger than whatever that is and … CLANK! PDCC bottoms out. Back to the guessing board…. there's a decoupling valve… there's a rubbery reservoir… they use special compressible fluid… for our American customers we must say….
But these are all What About Bob baby steps. Our ultimate destination down this road is active suspension technology. Which nobody has. Not even Porsche. Which if they did, they sure would not waste on PDCC.
#51
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For those that would deign to read a word or three from Porsche there's a reasonable description of the operation of PDCC in this post in the 991 Technical Information Thread. It is even fairly accessible to those with neither a background in physics nor an understanding of basic suspension dynamics should anyone on this thread be lacking in those characteristics.
Though, a careful and thoughtful reading along with a more-advanced background in dynamics might be helpful in disambiguating the operation of anti-roll bars, springs, and dampers.
Though, a careful and thoughtful reading along with a more-advanced background in dynamics might be helpful in disambiguating the operation of anti-roll bars, springs, and dampers.
#52
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For those that would deign to read a word or three from Porsche there's a reasonable description of the operation of PDCC in this post in the 991 Technical Information Thread. It is even fairly accessible to those with neither a background in physics nor an understanding of basic suspension dynamics should anyone on this thread be lacking in those characteristics. Though, a careful and thoughtful reading along with a more-advanced background in dynamics might be helpful in disambiguating the operation of anti-roll bars, springs, and dampers.
"There are no separate controls for PDCC. When PASM shock absorber tuning is selected, PDCC activates the relevant control programme automatically."
#54
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#56
#57
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Great link Chuck - thanks for sharing. It's the best explanation yet (and with pictures no less) of what PDCC is and does.
However - I'm still confused. The article states >>PDCC comes on whenever the engine is started<<. Fair enough. Then what does it mean when I press the PDCC button and the orange light comes on? Am I disabling PDCC? This would be counter to the other "button conventions" where the orange light indicates "enabling"...
DaveGee
14' 911_50
However - I'm still confused. The article states >>PDCC comes on whenever the engine is started<<. Fair enough. Then what does it mean when I press the PDCC button and the orange light comes on? Am I disabling PDCC? This would be counter to the other "button conventions" where the orange light indicates "enabling"...
DaveGee
14' 911_50
#58
Great link Chuck - thanks for sharing. It's the best explanation yet (and with pictures no less) of what PDCC is and does.
However - I'm still confused. The article states >>PDCC comes on whenever the engine is started<<. Fair enough. Then what does it mean when I press the PDCC button and the orange light comes on? Am I disabling PDCC? This would be counter to the other "button conventions" where the orange light indicates "enabling"...
DaveGee
14' 911_50
However - I'm still confused. The article states >>PDCC comes on whenever the engine is started<<. Fair enough. Then what does it mean when I press the PDCC button and the orange light comes on? Am I disabling PDCC? This would be counter to the other "button conventions" where the orange light indicates "enabling"...
DaveGee
14' 911_50
The part I'd really like to see expanded on is the bit about the direction valve. This is the reason I was having such a hard time with decoupling. When decoupled, the fluid has to have somewhere to go. Its a closed system, so the only place it can go is to the other side of the hydraulic piston. Okay. But then lets say you hit a bump going straight (decoupled) then turn sharply before rebound. So I guess that's where the directional valve comes in. But its frustrating, this is the most interesting part of the whole design and there's barely three words on it. Which is three words more than the Porsche article linked previously, but still!
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In combination with the sport button you have four modes of operation.
Last edited by worf928; 01-01-2015 at 09:56 PM.
#60
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My head hurts...
DaveGee
DaveGee