The new 991 C4S!!
#466
11-25-2012, 04:02 PM
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Join Date: Jan 2012
Location: Silicon Valley, California
Posts: 2,293
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Yeah I hear ya... all valid points!
That said, I'm really 2nd guessing myself on the PDCC.
If it wasn't for the reported "harder" ride of the C4/S because of stiffer anti-roll bars I would have left the PDCC of my build... I'm 100% sure it works for both performance and comfort but... I'm afraid that what you said about the Audi system could be the case with Porsche too... even with warranty it would be a royal pain in the @ss (at the low low price of 4K
).
Sooooooo I'm kinda hoping to get some firsthand feedback from you buddy hehehehe.
I figure if you don't find it too harsh on those NY roads I should be fine without PDCC too ( mind ya I'd need to take into consideration that the anti-roll bars on the C4S cab are stiffer still than on the coupe...)
Anyway looking forward to hearing all about the first impressions of your new C4S!
That said, I'm really 2nd guessing myself on the PDCC.
If it wasn't for the reported "harder" ride of the C4/S because of stiffer anti-roll bars I would have left the PDCC of my build... I'm 100% sure it works for both performance and comfort but... I'm afraid that what you said about the Audi system could be the case with Porsche too... even with warranty it would be a royal pain in the @ss (at the low low price of 4K
).Sooooooo I'm kinda hoping to get some firsthand feedback from you buddy hehehehe.
I figure if you don't find it too harsh on those NY roads I should be fine without PDCC too ( mind ya I'd need to take into consideration that the anti-roll bars on the C4S cab are stiffer still than on the coupe...)
Anyway looking forward to hearing all about the first impressions of your new C4S!
#467
11-25-2012, 04:14 PM
Yeah I hear ya... all valid points!
That said, I'm really 2nd guessing myself on the PDCC.
If it wasn't for the reported "harder" ride of the C4/S because of stiffer anti-roll bars I would have left the PDCC of my build... I'm 100% sure it works for both performance and comfort but... I'm afraid that what you said about the Audi system could be the case with Porsche too... even with warranty it would be a royal pain in the @ss (at the low low price of 4K).
Sooooooo I'm kinda hoping to get some firsthand feedback from you buddy hehehehe.
I figure if you don't find it too harsh on those NY roads I should be fine without PDCC too ( mind ya I'd need to take into consideration that the anti-roll bars on the C4S cab are stiffer still than on the coupe...)
Anyway looking forward to hearing all about the first impressions of your new C4S!
That said, I'm really 2nd guessing myself on the PDCC.
If it wasn't for the reported "harder" ride of the C4/S because of stiffer anti-roll bars I would have left the PDCC of my build... I'm 100% sure it works for both performance and comfort but... I'm afraid that what you said about the Audi system could be the case with Porsche too... even with warranty it would be a royal pain in the @ss (at the low low price of 4K
).Sooooooo I'm kinda hoping to get some firsthand feedback from you buddy hehehehe.
I figure if you don't find it too harsh on those NY roads I should be fine without PDCC too ( mind ya I'd need to take into consideration that the anti-roll bars on the C4S cab are stiffer still than on the coupe...)
Anyway looking forward to hearing all about the first impressions of your new C4S!
That being said, Audi had DRC failure problems with the RS6 in '03 and '04 and they still put the system (with the same problems) in the '06, '07 & '08 RS4.
#468
11-25-2012, 04:16 PM
But truth be told 2 years is not a long time plus it's not the same system, the PDCC for the Cayenne and Panamera was to big to fit on the 991 so the designed a brand new system.
Oh and BMW + Audi had some issues on theirs... but again different systems.
You know what I'm going to post some new stuff I found on the PDCC here because it seems more relevant to the C4/S than the C2/S (because of it's stiffer anti-roll bars).
I hope this one doesn't get taken down... it should be OK.
I found some excellent stuff on some of the 991 systems and posted it on 6speed when the 991 first came out but it was taken down because the place I got it from had an agreement with Porsche and I didn't... the result was that they lost their rights (for that specific info) and had to take all their info down as well...
Needless to say I had no idea I needed a license/publication agreement from Porsche...I figured this is the internet baby!
Anyway I don't want that to happen again... no good for anyone.
Last edited by Psycho Sid; 11-25-2012 at 04:46 PM.
#469
11-25-2012, 04:34 PM
OK fellas here's everything you ever wanted to know about the PDCC system...
From a tech point of view that is... the induction of under-steer, reliability, feel etc... that's another story.
OK, it's a VERY in-depth and longggg post but also VERY informative!
Enjoy!
If you want to check the source here's a link http://blogs.insideline.com/straight...carrera-s.html
Suspension Walkaround: 2012 Porsche 911 Carrera S
By Dan Edmunds | November 28, 2011
We thrashed the new 2012 Porsche 911 Carrera S at the track and then we tossed it at some curvaceous mountain roads. Now it's time to give the 911 a much-needed rest and hoist it up on our new Rotary two-post lift for a clear look at the suspension that does the business.
This new 911 is in fact a 991 in the language of Porsche engineering, which is why the 991 prefix appears on the various components we'll soon see. You may also notice a bit of grit and grime under there because the roads were wet much of the time we had it -- except at the track, thank goodness.
Let's get on with it. Here's the 411 on the new 911 suspension.
From here we see what looks like the standard 911 setup: humungous brakes and a MacPherson strut suspension.
A forged aluminum front knuckle (orange) grasps the bottom of the coil-over strut. Like other 911s before it, the 991's steering (yellow) meets it up ahead of the front axle's centerline.
It's electric power steering this time out, but the components are buried beneath covers we don't dare remove. Steering feel earned mixed reviews, but steering accuracy and direct response are as good or better than what we've found in the model it replaces.
The lower control arm is partially hidden by a convoluted bit of ductwork that sends cooling, soothing relief to the brakes.
A lateral link and a tension link come together in a bolted joint to make that lower control arm. Forged aluminum, of course.
As we've seen before, the front stabilizer bar loops over the top of the lower control arm to meet up with the stabilizer link (yellow,) but here that link is something very special, indeed.
Meanwhile, the damper within the strut housing is fitted with PASM (Porsche Active Stability Management,) a continuously variable damping system with two driver-selectable operating ranges, Normal and Sport.
The stabilizer bar link (green) is hydraulic, as is its opposite number on the other side of the car. A central computer looks at body height sensors, steering angle and a host of other factors to determine how to make them behave.
On straight roads they can go limp to essentially remove the stabilizer bar from the picture for a smooth ride. In corners they can be made to "overdrive" what the stabilizer bar could otherwise do on its own to utterly eliminate body roll. Or the computer can dial in any amount of roll stiffness in between, and it can change its mind in real time as road conditions or driver inputs fluctuate.
Porsche calls this Porsche Dynamic Chassis Control (PDCC) and it's the first time they've fit it to a 911-series vehicle. Whatever you call it, it flat works. This very car pulled 1.04 g on our skidpad, and some of the credit has to be put down to the way this system can make use of all four tires instead of leaning heavily on the outside ones.
You could theoretically achieve the same skidpad prowess with a pair of very big stabilizer bars, but then the car would ride like Grade A dog doo. Conversely, a hydraulic anti-roll system such as this doesn't need a physical stabilizer in between the left and right struts at all, but in that case there'd be no fail-safe if the system developed a fault.
As for those looming red brakes, the massive 6-piston Brembo calipers have a pair of fixed bridges (yellow) for maximum caliper stiffness. This means the calipers have to come off when it's time to change the brake pads which, incidentally, are equipped with electronic pad wear sensors.
And now we know what these big hoses (green) are for: they feed hydraulic fluid to the PDCC active stabilizer bar struts.
This sensor, along with three more at the other suspension corners, measures the position of the lower control arm to deduce the position of the tire.
The PDCC system compares the readings to that generated on the other side to measure body roll, and the PASM active damping system uses them to understand the motions of the wheels in order to determine the amount of damping required, be it for ride, cornering, dive/squat, etc. It's likely the headlights use 'em too for auto-leveling.
Here's another look at the 6-piston Brembo calipers. The ventilated and drilled rotors they grip are 13.4 inches in diameter and 1.3 inches thick. This car stopped from 60 mph in 102 feet.
Out back we find a new beautiful-looking multilink suspension.
A sea of forged aluminum surrounds a coil-over monotube shock that naturally contains the same PASM damping internals found up front.
Our new Rotary lift makes it easy to get directly under the car to get a clear view of the 991's two lower links.
The rear shock (and the spring that surrounds it) attaches directly to the rear knuckle for a 1-to-1 motion ratio. Such a ratio demands a long shock absorber, so the lower link employs a fork shape to allow the shock to sit low in the car.
Camber adjustments are made via an eccentric cam on this link's inner end.
Think of the rearmost pair of upper links (yellow) as an approximation of an upper control arm and the forward link (green) as a toe link. Close as they are to the hot brake rotor, their outboard pivot bushings must be made of hardy stuff.
The top of the rear stabilizer bar link (white) is just barely in view, but the fact that it's mounted directly to the rear knuckle means it operates at a 1-to-1 motion ratio.
Our trio of upper links attaches to a forged aluminum subframe (yellow) that contains a notch (black) for an eccentric adjusting cam for the toe link.
Just like the front, our 991 911's rear stabilizer links are hydraulically controlled by the PDCC system.
Also like the front, rear height sensors on each side relay the position of the rear suspension to the car's central brain, which in turn shares this data with numerous systems.
The lightening holes in the rear knuckle allow us to see how the electric parking brake worms itself into the hat section of the rotor, where a drum parking brake lays hidden.
As for the real rear brakes, they're made up of 4-piston fixed-bridge fixed calipers and fully ventilated rotors measuring 13-by-1.1 inches.
A small NACA duct admits air into ductwork that sends air to the rear calipers.
Here's another view of the same ductwork.
All of this rides on massive 20-inch wheels, another 911 first. The fronts measure 20-by-8.5 and are wrapped with 245/35ZR20 rubber, while the rears consist of 20-by-11 wheels and 295/30ZR20 tires. I'd like to tell you how much they weigh all mounted up, but I have not yet equipped our new shop with a suitable scale.
For what it's worth, Porsche claims that the wheels are lighter (than what and by how much they don't say) thanks to a flow-forming process. They also claim the tires have 7 percent less rolling resistance (than last year, presumably) which makes the 1.04 g skidpad number we measured all the more amazing.
From a tech point of view that is... the induction of under-steer, reliability, feel etc... that's another story.
OK, it's a VERY in-depth and longggg post but also VERY informative!
Enjoy!
If you want to check the source here's a link http://blogs.insideline.com/straight...carrera-s.html
Suspension Walkaround: 2012 Porsche 911 Carrera S
By Dan Edmunds | November 28, 2011
We thrashed the new 2012 Porsche 911 Carrera S at the track and then we tossed it at some curvaceous mountain roads. Now it's time to give the 911 a much-needed rest and hoist it up on our new Rotary two-post lift for a clear look at the suspension that does the business.
This new 911 is in fact a 991 in the language of Porsche engineering, which is why the 991 prefix appears on the various components we'll soon see. You may also notice a bit of grit and grime under there because the roads were wet much of the time we had it -- except at the track, thank goodness.
Let's get on with it. Here's the 411 on the new 911 suspension.
From here we see what looks like the standard 911 setup: humungous brakes and a MacPherson strut suspension.
A forged aluminum front knuckle (orange) grasps the bottom of the coil-over strut. Like other 911s before it, the 991's steering (yellow) meets it up ahead of the front axle's centerline.
It's electric power steering this time out, but the components are buried beneath covers we don't dare remove. Steering feel earned mixed reviews, but steering accuracy and direct response are as good or better than what we've found in the model it replaces.
The lower control arm is partially hidden by a convoluted bit of ductwork that sends cooling, soothing relief to the brakes.
A lateral link and a tension link come together in a bolted joint to make that lower control arm. Forged aluminum, of course.
As we've seen before, the front stabilizer bar loops over the top of the lower control arm to meet up with the stabilizer link (yellow,) but here that link is something very special, indeed.
Meanwhile, the damper within the strut housing is fitted with PASM (Porsche Active Stability Management,) a continuously variable damping system with two driver-selectable operating ranges, Normal and Sport.
The stabilizer bar link (green) is hydraulic, as is its opposite number on the other side of the car. A central computer looks at body height sensors, steering angle and a host of other factors to determine how to make them behave.
On straight roads they can go limp to essentially remove the stabilizer bar from the picture for a smooth ride. In corners they can be made to "overdrive" what the stabilizer bar could otherwise do on its own to utterly eliminate body roll. Or the computer can dial in any amount of roll stiffness in between, and it can change its mind in real time as road conditions or driver inputs fluctuate.
Porsche calls this Porsche Dynamic Chassis Control (PDCC) and it's the first time they've fit it to a 911-series vehicle. Whatever you call it, it flat works. This very car pulled 1.04 g on our skidpad, and some of the credit has to be put down to the way this system can make use of all four tires instead of leaning heavily on the outside ones.
You could theoretically achieve the same skidpad prowess with a pair of very big stabilizer bars, but then the car would ride like Grade A dog doo. Conversely, a hydraulic anti-roll system such as this doesn't need a physical stabilizer in between the left and right struts at all, but in that case there'd be no fail-safe if the system developed a fault.
As for those looming red brakes, the massive 6-piston Brembo calipers have a pair of fixed bridges (yellow) for maximum caliper stiffness. This means the calipers have to come off when it's time to change the brake pads which, incidentally, are equipped with electronic pad wear sensors.
And now we know what these big hoses (green) are for: they feed hydraulic fluid to the PDCC active stabilizer bar struts.
This sensor, along with three more at the other suspension corners, measures the position of the lower control arm to deduce the position of the tire.
The PDCC system compares the readings to that generated on the other side to measure body roll, and the PASM active damping system uses them to understand the motions of the wheels in order to determine the amount of damping required, be it for ride, cornering, dive/squat, etc. It's likely the headlights use 'em too for auto-leveling.
Here's another look at the 6-piston Brembo calipers. The ventilated and drilled rotors they grip are 13.4 inches in diameter and 1.3 inches thick. This car stopped from 60 mph in 102 feet.
Out back we find a new beautiful-looking multilink suspension.
A sea of forged aluminum surrounds a coil-over monotube shock that naturally contains the same PASM damping internals found up front.
Our new Rotary lift makes it easy to get directly under the car to get a clear view of the 991's two lower links.
The rear shock (and the spring that surrounds it) attaches directly to the rear knuckle for a 1-to-1 motion ratio. Such a ratio demands a long shock absorber, so the lower link employs a fork shape to allow the shock to sit low in the car.
Camber adjustments are made via an eccentric cam on this link's inner end.
Think of the rearmost pair of upper links (yellow) as an approximation of an upper control arm and the forward link (green) as a toe link. Close as they are to the hot brake rotor, their outboard pivot bushings must be made of hardy stuff.
The top of the rear stabilizer bar link (white) is just barely in view, but the fact that it's mounted directly to the rear knuckle means it operates at a 1-to-1 motion ratio.
Our trio of upper links attaches to a forged aluminum subframe (yellow) that contains a notch (black) for an eccentric adjusting cam for the toe link.
Just like the front, our 991 911's rear stabilizer links are hydraulically controlled by the PDCC system.
Also like the front, rear height sensors on each side relay the position of the rear suspension to the car's central brain, which in turn shares this data with numerous systems.
The lightening holes in the rear knuckle allow us to see how the electric parking brake worms itself into the hat section of the rotor, where a drum parking brake lays hidden.
As for the real rear brakes, they're made up of 4-piston fixed-bridge fixed calipers and fully ventilated rotors measuring 13-by-1.1 inches.
A small NACA duct admits air into ductwork that sends air to the rear calipers.
Here's another view of the same ductwork.
All of this rides on massive 20-inch wheels, another 911 first. The fronts measure 20-by-8.5 and are wrapped with 245/35ZR20 rubber, while the rears consist of 20-by-11 wheels and 295/30ZR20 tires. I'd like to tell you how much they weigh all mounted up, but I have not yet equipped our new shop with a suitable scale.
For what it's worth, Porsche claims that the wheels are lighter (than what and by how much they don't say) thanks to a flow-forming process. They also claim the tires have 7 percent less rolling resistance (than last year, presumably) which makes the 1.04 g skidpad number we measured all the more amazing.
#470
11-25-2012, 08:32 PM
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Join Date: Jan 2012
Location: Silicon Valley, California
Posts: 2,293
Rep Power: 150 
somebody spent time to dissect this piece of engineering art! Being electrical eng myself I can appreciate the level of R&D that went into designing this beauty. Thanks much for sharing it Sid...you rock man!!
Last edited by Fester; 11-25-2012 at 08:35 PM.
#471
11-26-2012, 08:20 AM
!!!BREAKING NEWS!!!
Hold onto your hats fellas...
In May Porsche will be releasing not 1... not 2... but 3 new 991's!!!
Yes they're dropping the veil on the 991 Turbo, Turbo S and... the GT3 ALL AT THE SAME TIME!
That is the word from the GM at my dealer whom just returned from Germany where the news was presented to PAG's dealer network... he also said the cabs for the Turbo/S will follow 3 months later.
I can't believe it after a very slowwwww trickling of new generation variants the boys at Porsche have decided to open the floodgates... maybe they've been paying attention to the cries of agony rising from the pages of 6speed.
Or decided they were losing customers because people are tired of waiting... foreplay can last only so long!
Whatever the reason Porsche has made sure next year is going to be exciting!
Cheers!
Hold onto your hats fellas...
In May Porsche will be releasing not 1... not 2... but 3 new 991's!!!
Yes they're dropping the veil on the 991 Turbo, Turbo S and... the GT3 ALL AT THE SAME TIME!
That is the word from the GM at my dealer whom just returned from Germany where the news was presented to PAG's dealer network... he also said the cabs for the Turbo/S will follow 3 months later.
I can't believe it after a very slowwwww trickling of new generation variants the boys at Porsche have decided to open the floodgates... maybe they've been paying attention to the cries of agony rising from the pages of 6speed.
Or decided they were losing customers because people are tired of waiting... foreplay can last only so long!
Whatever the reason Porsche has made sure next year is going to be exciting!
Cheers!
#472
11-26-2012, 10:57 AM
Registered User
Join Date: Oct 2012
Location: Jeddah, Saudi Arabia
Posts: 53
Rep Power: 20
The next instalment in the 'red lines' series: Part 2 - red line of performance
https://www.youtube.com/watch?v=qYQz...eature=g-all-u
https://www.youtube.com/watch?v=qYQz...eature=g-all-u
#473
11-26-2012, 07:00 PM
Those Crazy Germans!
As beautiful and functional as it is though... it does make one consider on how many level of design this amazing symphony of engineering can go wrong... I won't stop me from ordering it though, I think, yeah... no...yes...no...yes..
The 991 is such an expression of these types of systems that one either embraces it or tries one toe at a time to inevitably end up at the same place... the future of motor-sports performance enhancement.
This is crazy news because I heard "via dealer" that there will be a Targa for 2014.. that would make 4 variants if your info holds up. And yes I think they need to step it up for the 911 options similar to how they did with the Cayenne and Panamera! There is a unique customer for each and delaying is only forcing others to look at other options and the competition is just too good right now to give room for "brand creep".
Wasn't the Targa suppose to be released right after the C4/S coupe and cab!?
It's going to be a wide-body awd as well so I was actually expecting that to come out before the Turbo and GT3... wow lots going on!
I can't wait!
#474
11-26-2012, 07:25 PM
Might sound like a strange question but I was wondering if since I just put my order in for a new c4s build, is there some customer benefit with production line pics, updates, birth certificate(perks) to building from new?? I had some of those when ordering my '03.5 Esprit.. Just wondering...
#475
11-27-2012, 03:25 PM
Might sound like a strange question but I was wondering if since I just put my order in for a new c4s build, is there some customer benefit with production line pics, updates, birth certificate(perks) to building from new?? I had some of those when ordering my '03.5 Esprit.. Just wondering...
All I can say is stay on the dealer for info because otherwise you'll get nada!
Some have adopted the rather Zen disposition of just forgetting about your car until you get the call it's arrived...
That sounds the most sensible... if you have the constitution for that kinda thing, I know I sure don't so I end up driving my dealer crazy.
I always say to the GM, don't look at it as being unfortunate to have a client like myself... but rather the good fortune there's only one of me.
He'll reply... I wish that was true!!
Last edited by Psycho Sid; 11-27-2012 at 08:11 PM.
#478
11-28-2012, 10:10 AM
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Join Date: Oct 2012
Location: Jeddah, Saudi Arabia
Posts: 53
Rep Power: 20
I ordered SPASM on my C4S... my thoughts exactly !!
Ur welcome
!!Ur welcome
