PASM - normal and sport mode + Adjustable suspension for track use (toe, camber, rollbars)

 

Whats the point in this thread?

p.s. PASM would be more interesting if the springs, ride height & geo all adjusted at the push of a button.

 

Dan
PASM on the GT3 makes it MORE TRACK FRIENDLY drive there in normal mode, switch to Sport when you get there, what is not to like?

 

It depends on if it ends up undersprung and overdamped on track, just like the 997S PASM does. Sports kit on the 997S is standard dampers - so can 2 years development solve the problems that prompted Porsche to opt for standards in the sports kit.

I just think adjustable dampers of any form are a bit pointless if trying to change between road and track settings as the springs always end up a compromise, and if you soften a car with a low ride height it just grounds. I'd love to soften mine a bit on the road, but it would probably ground itself very hard on a yomp.

 

Dan
On some of the race cars we have Öhlins adjustable dampers and very firm Ti springs. We put a set of these on a street car and dialed back the adjustable shocks. Surprisingly, this is amazingly livable with on the street. Öhlins even offer this set up to customers for road use. They even have a nice piece of software to help you with the settings.
I don't mind whether I turn a **** on the shock or flick a switch in the car, if there is a mechanic handy. Hopwever, when I'm by myself and dressed up, I don't want to be fiddling and counting clicks and getting covered in grime!
At the same time as putting the shocks on, we fitted a lifting collar. This way sleeping policemen and ramps are no longer a problem for a low slung car, all Öhlins again, but electronics from Ruf.
I am sure that PAG has taken the sporting requirements into account.
I have noticed that what is acceptable in Germany, where many of the roads are of the billiard table persuasion, is not acceptable in the UK and even less so in the US. Suspension has to be made more pliant for these markets. I anticipate that there will be a lot more German development engineers coming over to Yorkshire and North Wales.
Firmer springs are not always faster on the track. The 996GT3RS has softer springs than the normal GT3. I don't know what was selected for the UK and the US, they could easily have been supplied with lower spring rates, this has happened in the past.
R+C

 

The US version 996 GT3 came with 40N/mm - 95N/mm springs per a PCNA publication (Panorama). As far as I know the Euro GT3RS uses the 45N/mm front springs.

Based on your comment, the Euro GT3 could be using stiffer springs than the GT3RS, something like 50N/mm. That makes sense with the contradictory info I have from a german turner and the info on the published US article.

My complaint with PASM is the continuos adjustment by itself while driving. It doesn't matter how fast is the ECU and the sensors, they can't predict the road ahead. If PASM was to adjust compression/rebound to a fixed setting, then it would be a blast to have it. I've driven two PASM equipped cars, and fast transitions are not as predictible, compared with my car, I keep naming it: Suspension Lag.

 

To quote:
"For the first time, the 911 GT3 boasts an active suspension. The standard Porsche Active Suspension Management (PASM) system offers two chassis in one: the default configuration is similar to that of the previous model and is suitable for driving on alternating road surfaces. In Sport mode, the system provides even firmer damping, enabling more focused dynamics for the racetrack."

 

That won't be much helpful. The reason I changed the suspension on my GT3 was that the stock shocks had too much compression for the streets, and that became a handicap for autocross. The adjustable Moton ClubSport allow a softer compression/rebound setting than the stock shocks, this keeps the tires on the ground at all times in autocross, and that result on faster lap times.

So I will expect plenty of people returning the 997 GT3 to the dealers (as happened to the 996 GT3), because the ride is too stiff.

I doubt that Porsche made the comfort setting as stiff as the stock 996 GT3 setting. It was stiff enough already, to the point that good drivers could turn very fast laps on slicks.

 

Indeed dependant on the track characteristics/surface quality stiffer is not always better!

Interesting to hear what you say about the RS vs GT3 spring rates, examples of both I've driven here (all UK cars) wouldn't suggest that to be honest, although I would say the difference is negligable (in terms of the spring rates that is).

Ohlins are the current "Daddys"...so much good stuff coming from them

 

Alan

As you are aware, one of the problems with springs is the accuracy of the nominal spring rate (aka Rate overlap). So if we are running Brand X (lets do this in lbs for our mostly US audience) 800 lb springs with a rate value +/- 5%, thats 40 lbs and we decide to go with slightly softer springs, say 750 lbs, we could be switching from soft 800 lb springs (800-40 = 760 lb) to firm 750 lb springs (750+37 = 787 lb), and actually end up with firmer springs.

All this is a long winded way of saying that I do not believe that PAG street cars use the very highest (read most expensive) specification springs, just very good ones. Without testing them, I suspect that rate overlap can become a factor. And how many of us keep spring dynos around to test our street cars?

The good news for listers is that one of the best spring manufacturers in the world is US based - Hypercoil and they are very understanding about exchanging springs until you find the right ones.

Audi is doing more and more chassis development in the UK. For a time, Winterkorn (the Capo di Capo) was flying weekly to Britain to oversee suspension testing. They have it pretty right with the new Gallardo, but absolute crap with everything else, so lots of work for chassis engineers.

R+C

 

I can see that in the new RS4 (drove one last week).

It's light years ahead of any other "performance" Audi I've driven!

I was actually "impressed"!

 

Well, the same day I drove the nouveau RS4, with the 'Sports suspension' option, I also drove the new Gallardo with all the latest bells and whistles.

The Sports suspension thumps like Brer Rabbit in the briar patch over expansion joints, and the car did not come alive until we got onto the back roads and started to 'earole it a bit. My co-driver, who is well known to every Porsche and sports car enthusiast in America, really did not like the car. Particulaly disliked was the way the seats goose your **** everytime you hit the sports button, apart from not being as wide as the current DOD seat specifation for fighters. If I want my bum hugging, I certainly don't want it done by a Germanic robotic device, although I'm assured that sort of thing is very popular in certain quarters! I dare say these seats will be a great success with proctologists.

To drive everything felt slightly remote and fuzzy, but we were coming off a period of testing some very handliong focused cars, so perhaps the comparison was not fair.

The Gallardo did not thump over expansion joints, it made us laugh aloud with glee. The RS4 was being used as a chase car, its inadequacies could not have been more cruelly exposed. So Audi does know how to make a proper car.

One of my Porsche mates uses a Gallardo as his winter car.

R+C

 

Heheheh I know what you mean about the seats...quite literally a pian in the ****!

The one I drove was on it's "standard" suspension (will there be a spot option over here I wonder?) and coped very well indeed, most of the day was spent on a and b roads.

I'm with you on the detached feeling but it's still a heck of a lot better than the previous one, particularly in that department!

Not had the pleasure of a Gallardo so can't compare them, however a very cruel comparison I reckon!

 

Nordschleife,

Thanks for informing or reminding the Rennnlist audience about spring rate variances. It is really a shame that there is some much error there. Many people proceed with suspension upgrades without ever checking the actual spring rates of what is on their car.

I consider suspension and aerodynamics to be the two most difficult areas on high performance and race cars.

This latest Porsche PASM package... I guess we wait and see if it is too much of a compromise for a GT3 type street car..

 

There are only about a handfull of people on this board who know even what caster, camber and toe do, let alone what compression and rebound settings they should set for driving conditions.

Porsche is not stupid, if they designed and built a car that the handfull of us could really appreciate it would....wait.....Porsche did, its called a cup car.

You know, now that I am thinking about it, even the Cup car does not come "setup" out of the box and needs some "upgrades" to be really track ready.