fbroen

Oh, and thank you for the Cayenne video, btw. I didn't know how different the Cayenne solution was, to achieve similar result.

worf928

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.

chuck911

Can you please enlighten us as to how PDCC knows when, and when not, to allow the "copy effect"?

Larry Cable

in a straight line there will be no yaw angle on the accelerometers (or the steering sensor) so the PDCC s/w can "leave" the hydraulics decoupled...

That's my guess.

chuck911

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.

worf928

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.

STG

+1

"There are no separate controls for PDCC. When PASM shock absorber tuning is selected, PDCC activates the relevant control programme automatically."

Cjwl

Old men really can't drive these machines and feel any difference, go to happy hour and save a dollar on ur drink

Cheekymonkeyman

just wait 'till your ***** drop. Then you'll still be a jerk but with a deeper voice... (Sorry mods)

Cjwl

I think I saw u tonite. Your car grey 911, you grey man with a comb over.

chuck911

Well I'll be… it pushes, pulls and decouples! http://digital.nexsitepublishing.com/i/254815/26

DaveGee

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

chuck911

I think the consensus is its a dummy button. Maybe someone knows if it activates Sport PDCC. But as far as I know when you hit Sport it activates Sport mode on everything- throttle, PASM, PDCC- all at once.

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!

worf928

It means more-or-less the same thing it means when that button does not have the PDCC label. In that case it is putting PASM into sport chassis mode. With PDCC that button puts PASM and PDCC in sport chassis mode.

In combination with the sport button you have four modes of operation.

DaveGee

My head hurts...

DaveGee