MANUAL

Bob,

Steer-by-wire and air brakes seem like thought-provocative ideas.

When you performed that ad hoc experiment, you stated:

They have a huge skid pad which allowed me to explore the capabilities of PSM in a 2003 996. While the test was hardly scientific, I was able to put the car into a spin or lurid slide by snapping the steering wheel into the turn. This was on a wet skidpad and I was going around 120 KPH. The sequence was, accelerate to speed, lift and simultaneously crack the wheel hard to the left. Before anyone comments, I agree that no driver in his right mind would do this ..except perhaps in a panic situation. I came away quite impressed with PSM - I had to brutally swerve to overcome it.

Please help me visualize. You were accelerating to approx. 120 KPH on a straight with zero degree steering input, correct? What kind of turn were you heading into? 45, 90, 135 degree corner? How many degrees roughly did you crack the wheel hard left? After cracking the wheel, did you hold it in that same position until the car went into a spin (oversteer) or a lurid slide (understeer)?

This skidpad must be much smaller than the PMG one:
http://www.ambrosiasw.com/~andrew/po...es/Image9.html

MANUAL

911's and AP1 S2000's are two of many that are sensitive to alignment and opportunity for alignment to go awry is present between the time the car leaves the factory to when the customer takes delivery. To this day, I have not read of any CGT driver stating they checked the alignment soon after delivery. And I doubt the dealer PDI includes an alignment check. I remember a few may have checked which setting their rear anti-sway bar was set after initial concerns were put forth, but that's all.

PogueMoHone

icon,

I'm with you!

I respect and value Alex's opinions a great deal, and he is very knowledgeable, with some outstanding posts, insights and ideas.

But on the CGT he has no objectivity since he has not driven (and refuses?) to drive the car. Just looking at something and opinining doesn't do it for me (on this one)...even if he were the greatest engineer on earth

I don't understand this one, but we all have our foibles! Of course I may be drinking the cool aid!

1AS

Okay by me. I've plum run out of thoughts. AS

PogueMoHone

I have one (a thought) for you, drive the car and then tell us what you think. Then, I (for one) would overweight your opinion, irrespective of the conclusion you reached.

Kaz

Nick, a regular car lost control on the same road. Are you proposing a ban on Audi S4's as well? The driver suffered a few broken ribs and was airlifted out.

Bob Rouleau

Manual - To answer your questions:

1) I got the car up to 75 MPH or so.
2) I cranked the wheel about 90 degrees very abruptly. There was no turn indicated, it was a huge empty skidpad.
3) The car went into a slide.
4) I did nothing on the first two occasions, I wanted to see if PSM could save it. It didn't.
5) On subsequent spins (cough) I worked at recovering and was able to stabilize the car after the initial slide/spin. I was pleased since it proved to me that grey matter could do better then a microprocessor.

Lastly I cannot view the pic you linked to ( I am using my Treo phone). The test was conducted on the large skid pad at PMG, either Charley or Delta (don't recall) but it is huge .. many football fields on a side .. enough that I felt safe deliberately spinning a car (not mine!) at 75 MPH.
Regards,

MANUAL

Bob,

Thank you. So far, your experimental methods are enlightening. Please clarify,

1) during #5 where you worked at recovering and were successful at stabilizing the car after the initial slide, was PSM still very much on and flashing by way of the triangular light?

2) And did you try a method where you turned PSM off and then worked, without touching the brakes which reactivates PSM, and were successful at recovering stabilization using only grey matter?

3) What was your recovery recipe for successful stabilization? A combination of brake, throttle, and steering?

Bob Rouleau

Manual - 1) Yes PSM was working - at least I assume it was because I never turned it off. I was not looking at the instrument panel - I was more concerned where the car was going to go

2) No. I left PSM on at all times.

3) Recovery was the usual, steering input countering the slide and incipient spin and throttle once the car was pointed where I wanted to go. Weight transfer to the rear of the car settled the back end and allowed me to proceed in a fairly straight line.

I believe that PSM helped the process and that recovery was easier than if PSM had been switched off. I didn't get the chance to try PSM off mode as by then the owner of the car was looking a little worried about my antics.

By the way, in another thread, Jason Andreas posted a link to a paper describing the evolution of ESP by Bosch. I was surprised to see that they are already at work on "active steering" to enhance the ability of ESP to prevent a loss of control. Based on my crude experiment, active steering would have improved the performance of the system. I'm not sure I want it on my track toy but it points to more complex "drive by wire systems".

Rgds,

1AS

Hi Bob,
This is what I've noted about myself, and how it relates to this issue. When I'm driving at the track, it takes me a few laps to get my reflexes right. Early on, I'm late reacting, and a little jerky, even tho I'm cautious. As the session moves on, I get quicker, but actually much quicker in a race than qualifying. I actually need another car in front of me to totally sharpen up.
On the street, I'm always distracted. Thinking about what I'm going to do when I get there, looking at the clock, checking my blackberry (!! disgusts me too), or just talking. It takes 100% concentration to drive really fast, react, correct, and anticipate. The sad truth is that ego aside, i"m one-half the driver on the street I am on the track.
Conclusion? That traction and skid controls are really helpful on my street car- in fact almost necessary in inclement conditions when I tend to push a little too hard. In a track car, I'd prefer ABS tho none of mine have it, and traction contol or ASC only for foul weather conditions (for those who haven't raced in the rain, it really connects your brain, feet and *********) Mostly now, if it rains for a race, I sit out, since it's too easy to turn a car into junk. Practice in the rain is still fun, but driving across the racing line in wet conditions is an eye-opener. For that, I'd prefer ASC and give up the second per lap. AS

Bob Rouleau

Alex - your post is thought provoking. My daily driver has ESP and it cannot be turned off, the button is a placebo which merely delays its intervention by a few milliseconds. The only time I see the ESp light flash is in winter - something we get a lot of around here and traction control is a godsend under heavy snow/ice conditions.

My Gt3 has only ABS and I agree that driving the track in the rain does connect body parts together in a special way. As an instructor I like teaching in the rain (unless there is a lot of standing water) because it puts a premium on finesse (very smooth inputs). It's a great teaching tool. I can see the advantage of ESP systems racing in the rain because you have to cross the slippery dry line twice in every corner. Note, I do not teach the "wet line" to novices.

I'm starting to come around, I would not avoid a car with ESP providing that it can be switched off when appropriate. What may not be evident to some reading this thread is that ESP (PSM in Porsche terms) is carefully calibrated to the tires supplied with the car. Yaw rate calibrations are not prepared to deal with the extra grip of R compound tires and under those circumstances PSM intervention is unwelcome. It's hard to fault Porsche for not knowing that some of us use ultra sticky tires, which is why I would prefer a system like Ferrari's which can be disabled when appropriate. On the street I leave CST (Italian for ESP/PSM) on all the time because intervention is not an issue unless I do something pretty stupid.. hasn't happened yet but like chicken soup, it can't hurt (sorry for the medical term Alex).

Best,

M758

Alex,
I agree with alot of that post. I also takes me a few warm up laps to push hard in my race car. Autocross is skill that helps you with being fast when cold due to the nature of the event, however the point is still quite valid.

My concern however that while it takes 100% concentration to drive 9/10 or 10/10 of your skill level on track doing so in any modern or semi modern Porsche is simply way to fast for public roads. It really has nothing to do with PSM or any electronic aids, but if you are taking a corner on street that REQUIRES you be inch perfect and being ready for the sligthest loss of control you are driving too fast. It is my experiece that even low hp Porsches are so capable that at legal speeds or even normal traffic speeds they are well within their performance window. If you are travelling at reasonable speeds the only way to get into trouble in one of these cars would be from some "emergency condition" such as oil or unusally slick surface, evading an object, mechanical issue or to be driving in some horrendus weather where normal dry speeds are simply not safe. (Snow/Ice for example).

In my mind things like PSM, DSC, etc should only be invoked on the road in these conditions and while they can be helpfull it is near impossible to prevent every incident from occuring. If you are driving PSM equiped car on the street and invoke PSM under anything other than extreme weather or emergency maneuvers you are simple going too fast.

I believe the reason we see and hear of "So Many" CGT spins and wrecks is two fold.
1) These cars are rare and evied by many and there are alot of folks who will "put down" and mock what they cannot obtain. Thus when something happens it gets magnified

2) There are owners of these car that feel because they such a capable car they are some how "above" the laws of physics and drive 120 mgh through a 30 mph hair pin. These types of people will get in trouble in anything no mater what you do to it. Now combine this small slice of owners with those that want to mock and ridicule the car at every turn and you get pictures blasted all over the world of this small number of owners.

Yes there is a 3rd reason incidents happen in the CGT. It is an amazing capable car that if not treated with respect all times can come back and bite you. Even very sane owners need to express caution even for that slight moment they feel like being an 18 year old on joy ride. Is that a design flaw? Is that a reason to force all sorts of stabilit aids on the car?

No I think not. The car realy is a super performing race car civilized just enough for the road. It is was not designed for every one and their grandmother to drive. Really the fact that an average driver can do just fine in the car if they respect it is testimony as to how flexible the car is.

Nick

A owner of a CGT and many other performance cars recently posted this on the Ferrarichat site. Based on my experience with thecar I believe he captures the essence of the CGT. His words are instructive and accurate at least from my standpoint.

"The CGT is a completely different animal. It's brutally explosive and way more responsive than any car I have ever driven. The best way I can describe it is that it feels like a Stradale on steroids. Everyting happens right NOW. I think the reason why so many people are losing control of them is because they get this false sense of security after driving it a while and think if they floor the car in second or even third gear like in a CS, F430, GT2, etc... that it will still allow them that half a second hesitation where they can reassess their driving line and correct any possible mistakes by maybe letting off the throttle. But in reality, the power comes on so instantaneously and builds so fast that it feels like trying to control a car after you've done a hard launch or worse yet done a clutch drop burnout when instead your just taking a sweeper in third gear. The car demands A LOT of respect in street driving situations. Much more so than a GT2 which you may remember had a pretty bad rep for a while there.

Personally, I know that I'm eventually going to replace my F430. Be it for a 430CS or its eventual successor. I can't ever imagine replacing the CGT for any other road car on this planet. It's just that good and that special!"

I suspect most will find something to support their views.

perfectlap

People aren't dying in these cars every day you know. When a fatality does occur the manufacturer needs to come under the highest possible scrutiny. Particularly if its a car where high speeds will often be driven. Porsche aren't going to examine themselves voluntarily to the degree that an ambitious lawyer will get them to play ball with the power of a court order. If the attorney is smart and not just a "settle for anything hack" he'll be trained in reviewing the documents that Porsche will send him. If he encounters any areas where Porsche could have done a better job but opted for a lower cost route (hard to imagine at that sticker price but certainly not unheard of) said lawyer will be all over it.

We may not like litigation because it has a way of letting people off the hook for their personal decisions but the way we let big corporations off the hook these days is even more outrageous. The Discovery process in Litigation benefits consumers as its the only way Major corporations will share information about their decision making with regards to safety.
Porsche are the most profitable car company in the world. Let's see if they've been investing those profits and making the fullest effort to ensure passenger safety.

p.s.
Personally I question the very wisdom of selling carbon fiber cars. In a collision the occupants in the other car could suffer tremendous injuries given the way carbon fiber breaks into razors.

Bob Rouleau

I commented on the lightning quick response of the CGT. I noticed it right away even at low speeds. This made me cautious aboout applying power and reinforced the rule of making gentle inputs. Am I so exceptional? I'd expect anyone with ordinary intelligence to realize they had something special underfoot and to exercise due caution. If I got the car sideways because I mashed the throttle, I'd be thinking that I was pretty stupid to have done that .... I wouldn't be blaming the car for having phenomenal response.

regards,