PDCC
12-26-2014, 12:44 PM
#16
On my'13 C2S with SPASM and PDCC, I have no control for the PDCC. It's on full-time and fully automatic. I do have a "shock absorber" button. It is not an on/off button; it switches the shock settings between "normal" and "sport." I've seen that '14 cars with PDCC have a PDCC button on the console, but I don't know what it does. Knowing how PDCC works, I can't imagine that you could actually turn it "off." But perhaps it triggers something like a normal/sport differentiation like my shock absorber button does?
I'll find out shortly, because my 991GTS is due any day and it too will have SPASM and PDCC.
DMoore
'13 991S
'13 970GTS
'15 991GTS soon...
I'll find out shortly, because my 991GTS is due any day and it too will have SPASM and PDCC.
DMoore
'13 991S
'13 970GTS
'15 991GTS soon...
12-26-2014, 12:59 PM
#17
Rennlist Member
On my 2014 911_50 there is a PDCC button with a light presumably indicating on/off.
DaveGee
DaveGee
12-26-2014, 02:05 PM
#18
Rennlist Member
I do not see how it is possible to completely disable PDCC and have the car be at all driveable; think about it, the function of PDCC is to dynamically adjust the effective spring rate of the sway bars.
Turning it off would require that the system either enter "full stiff" or "full soft" neither of which would be particularly comfortable, unless it was a 'fail safe mode'.
Turning it off would require that the system either enter "full stiff" or "full soft" neither of which would be particularly comfortable, unless it was a 'fail safe mode'.
12-26-2014, 02:29 PM
#20
Three Wheelin'
Chuck -- semantics, but I don't think the rollbars are any softer. The hydraulic droplinks make them "softer" -- or harder for that matter -- but the rollbars themselves (but for the droplinks) are the same I think. The hardware bars are pretty dern beefy on Sport PASM (PDCC) setup (S-PASM having beefier rollbars than PASM). I think logic dictates that the bars themselves need to be at least as stiff as non-PDCC bars, in order for the droplinks to have something to leverage against.
Last edited by fbroen; 12-26-2014 at 02:46 PM.
12-26-2014, 03:42 PM
#21
Racer
Thread Starter
Join Date: Feb 2014
Posts: 387
Likes: 0
Received 0 Likes
on
0 Posts
will try and upload pictures of it if i can work out how to do it!!!
12-26-2014, 04:00 PM
#23
$10 says the mfd says normal/sport chassis when you toggle the PDCC button. That's what it says in my 2012.5 with PDCC
same photo I posted last time we had this discussion, the consensus with that in 2014 they added the sticker so it was easier to tell which cars had PDCC:
same photo I posted last time we had this discussion, the consensus with that in 2014 they added the sticker so it was easier to tell which cars had PDCC:
12-26-2014, 04:07 PM
#24
Racer
Join Date: Jun 2014
Location: Silverstone, Great Britain.
Posts: 346
Likes: 0
Received 0 Likes
on
0 Posts
12-26-2014, 05:36 PM
#25
Chuck -- semantics, but I don't think the rollbars are any softer. The hydraulic droplinks make them "softer" -- or harder for that matter -- but the rollbars themselves (but for the droplinks) are the same I think. The hardware bars are pretty dern beefy on Sport PASM (PDCC) setup (S-PASM having beefier rollbars than PASM). I think logic dictates that the bars themselves need to be at least as stiff as non-PDCC bars, in order for the droplinks to have something to leverage against.
You're right about the hydraulics making the bar seem stiffer. But this only happens when you need it to happen. Going straight down the road, no steering input, no lateral load (lateral load without steering is possible, for example on a crowned road) the hydraulics do nothing and you get the more compliant ride of the softer bar. But the instant you tweak the wheel to dodge that pothole the hydraulics kick in making the bar seem stiffer. It all happens so fast you're unaware, so of course it always feels like the bar is stiff. But go drive a car without it, then you'll see.
This also works in terms of your leverage logic. Imagine your great big non-PDCC bar is so stiff it only twists 1 single degree even when transmitting max cornering load. Now imagine your PDCC car comes with a noodle so soft you can turn it with your hand. It has to rotate 360 degrees, one full turn, to transmit the same force. However, Porsche has mounted the noodle with actuators at either end capable of twisting the bar 720 degrees, crazy fast. Then, in that case, as far as you are able to tell, the noodle feels stiffer than the big bar. I've totally exaggerated and changed the actuators, but basically, that's PDCC.
12-26-2014, 05:42 PM
#26
Race Director
True, SPASM cars have stiffer bars than PASM, PDCC or no PDCC. But compared straight across the bars used with PDCC are softer. The whole point of the system is to achieve both a more compliant ride when you don't need performance AND a more responsive ride when you do. The first goal would be impossible with a bigger bar. Yet if you read Porsche literature they specifically mention improved ride. You're right about the hydraulics making the bar seem stiffer. But this only happens when you need it to happen. Going straight down the road, no steering input, no lateral load (lateral load without steering is possible, for example on a crowned road) the hydraulics do nothing and you get the more compliant ride of the softer bar. But the instant you tweak the wheel to dodge that pothole the hydraulics kick in making the bar seem stiffer. It all happens so fast you're unaware, so of course it always feels like the bar is stiff. But go drive a car without it, then you'll see. This also works in terms of your leverage logic. Imagine your great big non-PDCC bar is so stiff it only twists 1 single degree even when transmitting max cornering load. Now imagine your PDCC car comes with a noodle so soft you can turn it with your hand. It has to rotate 360 degrees, one full turn, to transmit the same force. However, Porsche has mounted the noodle with actuators at either end capable of twisting the bar 720 degrees, crazy fast. Then, in that case, as far as you are able to tell, the noodle feels stiffer than the big bar. I've totally exaggerated and changed the actuators, but basically, that's PDCC.
12-26-2014, 06:45 PM
#27
12-26-2014, 06:47 PM
#28
Rennlist Member
12-26-2014, 07:29 PM
#30
Rennlist Member