991 PDCC ?
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Discussion

cayman-black

Original Poster:

13,268 posts

246 months

s2000db

1,419 posts

183 months

Monday 16th April 2012
quotequote all
It's a shame that they can't be bothered to actually test them back to back, with say G force and slalom times...

I mean you could put up with a bit of twitchiness if it was 10% quicker, couldn't you? ;-)

Pat Cash

312 posts

260 months

Monday 16th April 2012
quotequote all
I've just spent the last 10 days on circuit in 991s both with and without PDCC.
For me a definite yes...

You notice the roll control much more watching from outside of the car actually. But from the inside, the additional grip levels become obvious in cornering speed.
Feels more compliant on the road too. Particularly when on 20"s.

However as mentioned previously, the car has so much grip now, that when it breaks away, you need to be much quicker to catch it!

Manks

28,176 posts

252 months

Monday 16th April 2012
quotequote all
Matt Saunders of Aotocar said:
During mixed road driving, the improvement in roll control was hard to detect....

....there seemed to be little improvement in ride compliance relative to the baseline set-up of the Carrera S we group tested a few months ago.

...and...

You’d certainly need a non-PDCC car, the right road and a particularly sensitive backside for a back-to-back comparison and to appreciate the net gain.

...and finally....

On the track, things are slightly different. PDCC does improve high-speed directional stability and outright lateral body control a little, but also seems to have a slight adverse affect on the fluid, predictable limit handling of the 991.
Drive the cars back to back, as a number of us have done now, and the difference is obvious.

It's a bit odd that the writer couldn't notice the quite obvious difference on the road but noticed a "slight adverse effect on the fluid, predictable limit handling" on the track, even though it was a few months ago that he drove the non-PDCC car.




Blue62

10,587 posts

182 months

Monday 16th April 2012
quotequote all
This one's going to run and run isn't it? Mentioned in a previous post that the guy I sat next to ona recent Porsche experience day suggested he preferred non PDCC for everyday use, yet quite a number of owners and prosepctive owners suggest it's essential for hooning. What is a boy to do?

GuillaumeB

329 posts

203 months

Monday 16th April 2012
quotequote all
Manks said:
Drive the cars back to back, as a number of us have done now, and the difference is obvious.

It's a bit odd that the writer couldn't notice the quite obvious difference on the road but noticed a "slight adverse effect on the fluid, predictable limit handling" on the track, even though it was a few months ago that he drove the non-PDCC car.
Can't say I was particularly impressed with this one page review. They should have got both cars and tested them back to back and given us something a bit more substantial and objective. Lots of us are interested.

The fact that the writer couldn't really notice the effect of PDCC on normal roads undermines the whole article anyway. I found it a very appreciable difference on the Surrey roads around here. For starters in PASM sport setting you could hardly feel any of the bumps on the road, almost a magic carpet. Yet the suspension feels very firm and steering inputs are incredibly precise.

As I mentioned in a previous post at the slalom course at Silverstone (Stowe Circuit) the PDCC car was amazing. It really does transform the car's handling - certainly nothing "slight"!

betternotbigger

1,059 posts

205 months

Monday 16th April 2012
quotequote all
Having been left lukewarm by the non-PDCC 991 I tried a couple of months back, I'm having a jaunt in a PDCC + SPASM -20mm one later this week. Hoping I can tell the difference.

GuillaumeB

329 posts

203 months

Monday 16th April 2012
quotequote all
betternotbigger said:
PDCC + SPASM -20mm
Now that should be interesting!!

betternotbigger

1,059 posts

205 months

Monday 16th April 2012
quotequote all
GuillaumeB said:
betternotbigger said:
PDCC + SPASM -20mm
Now that should be interesting!!
That's what I thought. I have SPASM on my GTS so it'll be a telling comparison. Pity the tyres won't be the same, 'cos that kind of ruins the experiment. I've got smooth-riding MPSS on the GTS, while the 991 has Pirellis.

GuillaumeB

329 posts

203 months

Wednesday 18th April 2012
quotequote all
betternotbigger said:
That's what I thought. I have SPASM on my GTS so it'll be a telling comparison. Pity the tyres won't be the same, 'cos that kind of ruins the experiment. I've got smooth-riding MPSS on the GTS, while the 991 has Pirellis.
When is the test drive?

Tony 1234

3,465 posts

257 months

Wednesday 18th April 2012
quotequote all
Blue62 said:
This one's going to run and run isn't it? Mentioned in a previous post that the guy I sat next to ona recent Porsche experience day suggested he preferred non PDCC for everyday use, yet quite a number of owners and prosepctive owners suggest it's essential for hooning. What is a boy to do?
PDCC for me everytime, better (softer) ride than a non PDCC car I tried before I ordered mine

betternotbigger

1,059 posts

205 months

Wednesday 18th April 2012
quotequote all
Just back from the test drive fellas and here are my thoughts. I'll try not to do a standard test drive review but to focus on those aspects of the 991 which are influenced by the PSE, PDCC or SPASM -20mm options:

Comparison: 991 C2S vs 991 C2S PDCC w/ SPASM -20mm and PSE, both on Pirellis (usual steer 997 GTS SPASM -20mm on Michelin MPSS)

Handling/Grip

It was a wet morning here so less grip biggrin available than on my dry test drive of the non-PDCC car. Turn-in was phenomenal and understeer at low speeds markedly absent on both 991s. Interestingly (and in contrast to EVO's observations), I found it quite easy to unsettle the PDCC car and get it to break away (ham-fistedly at least) doing about 40mph round a tight roundabout (exactly on the speed limit, of course). Both 991s have the same characteristic of seeming to pull from the front rather than pushing from behind, where the GTS offers up more typical pendulum dynamics and greater sensitivity to throttle inputs.

Does the PDCC improve handling? I noticed it less than I expected to. Where it becomes most evident is in a slaloming situation such as entering an empty roundabout at speed, where a right turn follows a left almost immediately. Is it essential? Definitely not.

Ride/Compliance

Tyre type and pressures could be a major variable here but I felt the PDCC car definitely provided a smoother ride than the standard 991, and this with lowered suspension which ought to have sent findings the other way. Rather a nice combination in fact. Nowhere was it crashy. Perhaps it's just familiarity but I enjoyed being on a lowered suspension, and some of the filtering/distancing effect of the new technology is definitely minimised, very much for the better. Compared to my GTS the comfort was not dissimilar, but clearly more comfortable in absolute terms since the Pirellis are much crashier than my Michelins.

Road Noise

When I drove the standard 991 a while back, I'd been disappointed with the high levels of tyre roar compared to what I'd been led to expect from the reviews. And the PDCC car confirmed these initial observations. Difficult to judge on a wet day and I guess tyre type is a significant influence. Let's be fair though, there clearly is some improvement because I'd say noise levels (on loud Pirellis) were similar to my (quiet rubber) MPSS-shod GTS. Nevertheless, it's hardly the executive express you read about.

Sports Exhaust

Superb. I didn't like the sound symposer on the standard car but it seems to work much better in concert with the PSE. I'd pay the extra no doubt at all.

Steering

Perhaps it's the shorter springs of the lowered car which had me definitely preferring the steering of the PDCC car over the standard 991. The steering definitely feels less filtered and more direct. Interestingly, the wider front track, which had a very noticeable effect on steering feel in the standard 991 was less in evidence on the PDCC car. Tyre pressures?

However, stepping back in the GTS, the lightness and extra communication offered by the 997 steering is a revelation when you step from a 991. Easily the single biggest demerit of the new car. I can sum it up best by saying the lighter 991 feels heavier than the more dense 997.

Sports Seats Plus

The PDCC car was well optioned for sportiness (at £99,853!!) and the sports seats were, to my frame, a big improvement on the comfort seats (I think they differentiate them as Sports seats and Sports seats Plus). A definite yes for me, but even better if they do them in Alcantara.

And the $64,000 (or £99,853) question: If I were buying a 991 would I spec PDCC w/ SPASM -20mm?

I would give it serious thought, though not for the primary anti-roll benefits of PDCC, but for the secondary advantage of bringing the benefits of the SPASM lowered suspension (improved steering response, lower CoG, meaner stance, better connection to the road) within a more compliant range.

Or you could just insist they fit Michelin PSS to a SPASM -20mm car and enjoy the same benefits!! Works great on my GTS.

Edited by betternotbigger on Wednesday 18th April 12:47

Manks

28,176 posts

252 months

Wednesday 18th April 2012
quotequote all
betternotbigger said:
Just back from the test drive fellas and here are my thoughts. I'll try not to do a standard test drive review but to focus on those aspects of the 991 which are influenced by the PSE, PDCC or SPASM -20mm options:

Comparison: 991 C2S vs 991 C2S PDCC w/ SPASM -20mm and PSE, both on Pirellis (usual steer 997 GTS SPASM -20mm on Michelin MPSS)

Handling/Grip

It was a wet morning here so less grip biggrin available than on my dry test drive of the non-PDCC car. Turn-in was phenomenal and understeer at low speeds markedly absent on both 991s. Interestingly (and in contrast to EVO's observations), I found it quite easy to unsettle the PDCC car and get it to break away (ham-fistedly at least) doing about 40mph round a tight roundabout (exactly on the speed limit, of course). Both 991s have the same characteristic of seeming to pull from the front rather than pushing from behind, where the GTS offers up more typical pendulum dynamics and greater sensitivity to throttle inputs.

Does the PDCC improve handling? I noticed it less than I expected to. Where it becomes most evident is in a slaloming situation such as entering an empty roundabout at speed, where a right turn follows a left almost immediately. Is it essential? Definitely not.

Ride/Compliance

Tyre type and pressures could be a major variable here but I felt the PDCC car definitely provided a smoother ride than the standard 991, and this with lowered suspension which ought to have sent findings the other way. Rather a nice combination in fact. Nowhere was it crashy. Perhaps it's just familiarity but I enjoyed being on a lowered suspension, and some of the filtering/distancing effect of the new technology is definitely minimised, very much for the better. Compared to my GTS the comfort was not dissimilar, but clearly more comfortable in absolute terms since the Pirellis are much crashier than my Michelins.

Road Noise

When I drove the standard 991 a while back, I'd been disappointed with the high levels of tyre roar compared to what I'd been led to expect from the reviews. And the PDCC car confirmed these initial observations. Difficult to judge on a wet day and I guess tyre type is a significant influence. Let's be fair though, there clearly is some improvement because I'd say noise levels (on loud Pirellis) were similar to my (quiet rubber) MPSS-shod GTS. Nevertheless, it's hardly the executive express you read about.

Sports Exhaust

Superb. I didn't like the sound symposer on the standard car but it seems to work much better in concert with the PSE. I'd pay the extra no doubt at all.

Steering

Perhaps it's the shorter springs of the lowered car which had me definitely preferring the steering of the PDCC car over the standard 991. The steering definitely feels less filtered and more direct. Interestingly, the wider front track, which had a very noticeable effect on steering feel in the standard 991 was less in evidence on the PDCC car. Tyre pressures?

However, stepping back in the GTS, the lightness and extra communication offered by the 997 steering is a revelation when you step from a 991. Easily the single biggest demerit. I can sum it up best by saying the lighter 991 feels heavier than the more dense 997.
Thanks for that. Did the car have Power Steering Plus? Not sure I agree that the 997 feels lighter, to be honest. Certainly not my Gen 1 997 vs the 991 with PSP.

Incidentally, about the pendulum thing: It's still there, it's just easier to forget about in the 991. I was reminded where the engine is the other evening when braking far too hard and too late into a right-hander.








PocoLoco

112 posts

193 months

Wednesday 18th April 2012
quotequote all
Excellent post - thanks!

betternotbigger

1,059 posts

205 months

Wednesday 18th April 2012
quotequote all
PocoLoco said:
Excellent post - thanks!
Added some more info after accidentally pressing "Submit" so here it is again this time in full. Sorry for cock-up.

Just back from the test drive fellas and here are my thoughts. I'll try not to do a standard test drive review but to focus on those aspects of the 991 which are influenced by the PSE, PDCC or SPASM -20mm options:

Comparison: 991 C2S vs 991 C2S PDCC w/ SPASM -20mm and PSE, both on Pirellis (usual steer 997 GTS SPASM -20mm on Michelin MPSS)

Handling/Grip

It was a wet morning here so less grip available than on my dry test drive of the non-PDCC car. Turn-in was phenomenal and understeer at low speeds markedly absent on both 991s. Interestingly (and in contrast to EVO's observations), I found it quite easy to unsettle the PDCC car and get it to break away (ham-fistedly at least) doing about 40mph round a tight roundabout (exactly on the speed limit, of course). Both 991s have the same characteristic of seeming to pull from the front rather than pushing from behind, where the GTS offers up more typical pendulum dynamics and greater sensitivity to throttle inputs.

Does the PDCC improve handling? I noticed it less than I expected to. Where it becomes most evident is in a slaloming situation such as entering an empty roundabout at speed, where a right turn follows a left almost immediately. Is it essential? Definitely not.

Ride/Compliance

Tyre type and pressures could be a major variable here but I felt the PDCC car definitely provided a smoother ride than the standard 991, and this with lowered suspension which ought to have sent findings the other way. Rather a nice combination in fact. Nowhere was it crashy. Perhaps it's just familiarity but I enjoyed being on a lowered suspension, and some of the filtering/distancing effect of the new technology is definitely minimised, very much for the better. Compared to my GTS the comfort was not dissimilar, but clearly more comfortable in absolute terms since the Pirellis are much crashier than my Michelins.

Road Noise

When I drove the standard 991 a while back, I'd been disappointed with the high levels of tyre roar compared to what I'd been led to expect from the reviews. And the PDCC car confirmed these initial observations. Difficult to judge on a wet day and I guess tyre type is a significant influence. Let's be fair though, there clearly is some improvement because I'd say noise levels (on loud Pirellis) were similar to my (quiet rubber) MPSS-shod GTS. Nevertheless, it's hardly the executive express you read about.

Sports Exhaust

Superb. I didn't like the sound symposer on the standard car but it seems to work much better in concert with the PSE. I'd pay the extra no doubt at all.

Steering

Perhaps it's the shorter springs of the lowered car which had me definitely preferring the steering of the PDCC car over the standard 991. The steering definitely feels less filtered and more direct. Interestingly, the wider front track, which had a very noticeable effect on steering feel in the standard 991 was less in evidence on the PDCC car. Tyre pressures?

However, stepping back in the GTS, the lightness and extra communication offered by the 997 steering is a revelation when you step from a 991. Easily the single biggest demerit of the new car. I can sum it up best by saying the lighter 991 feels heavier than the more dense 997.

Sports Seats Plus

The PDCC car was well optioned for sportiness (at £99,853!!) and the sports seats were, to my frame, a big improvement on the comfort seats (I think they differentiate them as Sports seats and Sports seats Plus). A definite yes for me, but even better if they do them in Alcantara.

And the $64,000 (or £99,853) question: If I were buying a 991 would I spec PDCC w/ SPASM -20mm?

I would give it serious thought, though not for the primary anti-roll benefits of PDCC, but for the secondary advantage of bringing the benefits of the SPASM lowered suspension (improved steering response, lower CoG, meaner stance, better connection to the road) within a more compliant range.

Or you could just insist they fit Michelin PSS to a SPASM -20mm car and enjoy the same benefits!! Works great on my GTS.

betternotbigger

1,059 posts

205 months

Wednesday 18th April 2012
quotequote all
Manks said:
Thanks for that. Did the car have Power Steering Plus? Not sure I agree that the 997 feels lighter, to be honest. Certainly not my Gen 1 997 vs the 991 with PSP.

Incidentally, about the pendulum thing: It's still there, it's just easier to forget about in the 991. I was reminded where the engine is the other evening when braking far too hard and too late into a right-hander.
No it didn't have Power Steering Plus. And yes, the pendulum is still there, how else did I get the back out at 40mph on a steady throttle? But the sense of being pushed through the corner by a giant claw is missing. Anyway, let's try to keep on the subject of PDCC or else we'll be debating GTS vs 991 all day long smile

You've got a PDCC-equipped car, albeit without SPASM -20mm. Is my comparison of the two 991s fair?

Manks

28,176 posts

252 months

Wednesday 18th April 2012
quotequote all
betternotbigger said:
Manks said:
Thanks for that. Did the car have Power Steering Plus? Not sure I agree that the 997 feels lighter, to be honest. Certainly not my Gen 1 997 vs the 991 with PSP.

Incidentally, about the pendulum thing: It's still there, it's just easier to forget about in the 991. I was reminded where the engine is the other evening when braking far too hard and too late into a right-hander.
No it didn't have Power Steering Plus. And yes, the pendulum is still there, how else did I get the back out at 40mph on a steady throttle? But the sense of being pushed through the corner by a giant claw is missing. Anyway, let's try to keep on the subject of PDCC or else we'll be debating GTS vs 991 all day long smile

You've got a PDCC-equipped car, albeit without SPASM -20mm. Is my comparison of the two 991s fair?
PSS makes a difference to how heavy the car feels.

Is your review fair? I think it is as far as you could tell in the wet and with a -20mm car. The Pirellis prefer warm, dry conditions and in cold, wet ones are a bit skittish. Damp, greasy roads are not the place to compare PDCC and non-PDCC 991s on stock tyres.

You have picked out some different characteristics from those that I think are most noticeable. However, we are agreed that PDCC is not essential. I would spec it again a performance orientated car, but if I were based in a city and had little opportunity for fast B road driving or track days I would spend the money elsewhere.















betternotbigger

1,059 posts

205 months

Wednesday 18th April 2012
quotequote all
Manks said:
PSS makes a difference to how heavy the car feels.

Hmmm. Not sure I agree with you there. When I first tried a 991, my GTS was on Bridgestones, and I had exactly the same sensation moving between the two. I think it's more to do with the new steering.


Manks said:
You have picked out some different characteristics from those that I think are most noticeable.
What are the defining characteristics for you?

Manks

28,176 posts

252 months

Wednesday 18th April 2012
quotequote all
betternotbigger said:
Manks said:
You have picked out some different characteristics from those that I think are most noticeable.
What are the defining characteristics for you?
The car corners flat, has more grip and is less affected by uneven road surfaces. That's about it.

GuillaumeB

329 posts

203 months

Wednesday 18th April 2012
quotequote all
betternotbigger said:
Added some more info after accidentally pressing "Submit" so here it is again this time in full. Sorry for cock-up.

Just back from the test drive fellas and here are my thoughts. I'll try not to do a standard test drive review but to focus on those aspects of the 991 which are influenced by the PSE, PDCC or SPASM -20mm options:

Comparison: 991 C2S vs 991 C2S PDCC w/ SPASM -20mm and PSE, both on Pirellis (usual steer 997 GTS SPASM -20mm on Michelin MPSS)

Handling/Grip

It was a wet morning here so less grip available than on my dry test drive of the non-PDCC car. Turn-in was phenomenal and understeer at low speeds markedly absent on both 991s. Interestingly (and in contrast to EVO's observations), I found it quite easy to unsettle the PDCC car and get it to break away (ham-fistedly at least) doing about 40mph round a tight roundabout (exactly on the speed limit, of course). Both 991s have the same characteristic of seeming to pull from the front rather than pushing from behind, where the GTS offers up more typical pendulum dynamics and greater sensitivity to throttle inputs.

Does the PDCC improve handling? I noticed it less than I expected to. Where it becomes most evident is in a slaloming situation such as entering an empty roundabout at speed, where a right turn follows a left almost immediately. Is it essential? Definitely not.

Ride/Compliance

Tyre type and pressures could be a major variable here but I felt the PDCC car definitely provided a smoother ride than the standard 991, and this with lowered suspension which ought to have sent findings the other way. Rather a nice combination in fact. Nowhere was it crashy. Perhaps it's just familiarity but I enjoyed being on a lowered suspension, and some of the filtering/distancing effect of the new technology is definitely minimised, very much for the better. Compared to my GTS the comfort was not dissimilar, but clearly more comfortable in absolute terms since the Pirellis are much crashier than my Michelins.

Road Noise

When I drove the standard 991 a while back, I'd been disappointed with the high levels of tyre roar compared to what I'd been led to expect from the reviews. And the PDCC car confirmed these initial observations. Difficult to judge on a wet day and I guess tyre type is a significant influence. Let's be fair though, there clearly is some improvement because I'd say noise levels (on loud Pirellis) were similar to my (quiet rubber) MPSS-shod GTS. Nevertheless, it's hardly the executive express you read about.

Sports Exhaust

Superb. I didn't like the sound symposer on the standard car but it seems to work much better in concert with the PSE. I'd pay the extra no doubt at all.

Steering

Perhaps it's the shorter springs of the lowered car which had me definitely preferring the steering of the PDCC car over the standard 991. The steering definitely feels less filtered and more direct. Interestingly, the wider front track, which had a very noticeable effect on steering feel in the standard 991 was less in evidence on the PDCC car. Tyre pressures?

However, stepping back in the GTS, the lightness and extra communication offered by the 997 steering is a revelation when you step from a 991. Easily the single biggest demerit of the new car. I can sum it up best by saying the lighter 991 feels heavier than the more dense 997.

Sports Seats Plus

The PDCC car was well optioned for sportiness (at £99,853!!) and the sports seats were, to my frame, a big improvement on the comfort seats (I think they differentiate them as Sports seats and Sports seats Plus). A definite yes for me, but even better if they do them in Alcantara.

And the $64,000 (or £99,853) question: If I were buying a 991 would I spec PDCC w/ SPASM -20mm?

I would give it serious thought, though not for the primary anti-roll benefits of PDCC, but for the secondary advantage of bringing the benefits of the SPASM lowered suspension (improved steering response, lower CoG, meaner stance, better connection to the road) within a more compliant range.

Or you could just insist they fit Michelin PSS to a SPASM -20mm car and enjoy the same benefits!! Works great on my GTS.
Great post, many thanks for sharing your findings with us. Very interesting to see that PDCC makes the SPASM option much more compliant. With the standard PASM you can probably now imagine its effect on the suspension of the car over uneven surfaces. Shame it was wet though as it definitely needs to be pushed quite hard to realise the benefits of the anti-roll bars. My experience at the slalom course at Silverstone (Stowe Circuit) was amazing - so much grip!