NJ-GT

Well said.

I would like to add that due to a poor setup, on the same track/tires/drivers/weather I could only improve my best time by fractions of a second per lap when I went with Moton and upper monoball plates.

Fixing all the other suspension flaws as mentioned by you, keeping the same shocks, and setting up the car accordingly, I was able to drop my times by 4 seconds, altough on a slightly better tire (A6 vs. MPSC), probably over 3 seconds improvement on a 60 secs course using MPSC.

A good setup with Moton/JRZ/KW/Ohlins/Penske and linear springs would make the 997 GT3/GT3 RS better on the street and track.

Moton CS provide a softer ride even though I'm running much stiffer springs and every suspension bushing is metallic.

mooty

not that i mind, but i want to make sure my car is not an anomoly.
with your set up on street, do you get rattles from the metallic bushings? my does, i just open the windwo and drive a bit faster to drown it out.

997gt3north

mooty,

As i am knew to this gt3 stuff, i appreciate your post on the rattle with metallic bushings.
I previously went this route with S4 (metallic ball joints in the control arms) and after the car warmed up for 5 minutes the sound would begin.
I eventually decided as my car was mostly a street car to remove them and just get the absolute best aftermarket suspension (Ohlins from Stasis Engineering) and change the sways to make the car as neutral as possible.
The sound drove me crazy and it just wasn't worth it to me.

RS 197

Good points....

Another one to consider........

As far as the Ring is concerend, I would assume you have been on it. I drove 10 laps in a rented 3 series BMW. There is no way my cup car at it's current setting could get around the track. It is bumby and the carosell would rip off the front spoiler and the exhaust off. I would need higher walled tires and a way softer set up to keep from bouncing off the track..........

Think about this. PASM was developed in part for the Ring. Every sports car that comes out of Germany is imediatly tested at the Ring. Porsche can not make a car too stiff for the Ring can they??? The faster the car gets around there the better.

After 10 laps in the rain I can see why they added TC also. You put a wheel off and you are toast. There is very little run off at the Ring. I am sure that the guys that spend plenty of time there are not complaining.

If I drove a car in Germany every day I would appreciate the PASM and TC. Every day is like a DE track day over there.

Nordschleife

Yeah, I've been on the Nordschleife, a bit

I think it costs € 2,500 to convert a Cup car to Nordschleife suspension configuration, as I said its not expensive, I don't have my price file with me, but it certainly was surprisingly (pleasantly) inexpensive.

Given that Porsche AG knows perfectly well that the Nordschleife requires quite soft suspension, I can only assume that too many of the engineers spend too much time testing on the tracks at Weissach and Leipzig (and Paul Ricard) and only the test drivers are spending a lot oftime at the Nordschleife.

Lord knows what they are thinking, they know perfectly well that in the US and UK, roads are not good, even in Germany, where the cars are driven hard, the Sport setting is no good on even good autobahnen at high speed.

Personally, I think they ran with the PASM because they had it.... and it would have looked bad if they had removed it.

I agree about the the traction control, and really good ABS, driving in Autumn(Fall), Winter and Spring can be tedious without it. I particularly notice leaves in the Autumn being really slippery (they cause Deutsche Bahn (German Railways) unbelievable problems each Autumn).

Ultimately, I don't think the comparisons between Germany and the US are terribly useful. In Europe the car is more likely to be driven year round and to do a decent annual milage. Also, like most people over here, I dawdle along getting organised around town, only sharpening up as I approach the Autobahn on ramp, and then I really bury it, but avoid the traffic light grand prix. I tend to measure fule consumption in minutes per tank. On the East Coast of the US, I absolutely try and avoiding driving.

R+C

fbfisher

That's exactly what I thought when I started reading this thread. I read the article last night and I thought the author really liked it.

I found the bit about sport and normal mode a little confusing, seems like the drivers prefered normal mode. They seemed to all really like the car and ultimately prefer it over the 996 version.

Nordschleife

Yup - they put them in the rotary file


R+C

Crazy Canuck

Interesting article and Rennteam thread.

enthusiast

The 997 GT3 is better in some areas than the 996 GT3. A Rest of World spec 997 GT3 optioned with performance in mind is better than a North America spec one!

frayed

Johannes' second opinion in Excellence

Finally got around to reading it this morning. He loved the car with one exception; he was fighting oversteer as he pushed the car.

Noticed they started out at 31 psi. That's way too high in my experience, usually around 26 psi all around gets the pressures around 32/36 fr/rr. I've run rear pressures on a set of Corsas in my C4S up to 42 psi once and the car became a handful, oversteering like mad, initiating PSM all around the track.

Also, the car had more front camber and less rear camber than the comparative 996. Doesn't appear toe was checked.

Seems like a simple case of playing getting a good track alignment and monitoring tire pressures to get a better fr/rr balance.

mitch236

Has any of you put your GT-3 on a rack. I did and what I noticed is that from the factory, the front sway bar was set to full soft and the rear was set to full stiff. That seemed to be contrary to what Porsche has been thinking of late, producing a car that understeers. That may also have added to the author's belief that the car was tail happy.

I think ( and really hope) that with time, I will get my car setup very well. My only concern is with PASM and I don't really care if they "stiffen" the settings for the RS, it still is a dynamic system that is continually changing while on the track. I want a suspension that is predictable. Hopefully, someone will figure a way to get the computer that controls PASM to stay at one setting. That would solve the whole PASM problem. Of course, if that doesn't happen, I will upgrade the components.

viperbob

Yeah, I just hope he doesn't tear up my GT3....

Carrera GT

All else being equal, a soft front bar and stiff rear bar will contribute to oversteer, not understeer.
The factory settings are 4/5 and 3/3 rear.
I've had my car on an alignment rack. The ride height was out of spec and adjusted the car to the "circuit" settings in the owner's manual.
With the front bar changed to full soft and the rear at full stiff, the car still pushes with PASM "off" or in the normal setting.
Interestingly, with the bars at 3/5 and 2/3 and PASM in "Sport" I found less overall body roll (not that I'm happy about PASM compensating for the extra load in this way) and less low speed understeer (eg. T11 at Laguna.)
The faster sweepers give enough time and space to control the turn in and avoid understeer through the apex. Then, it's just a matter of how much slip you're prepared to commit.
I think the 997 needs a stiffer rear bar. Maybe the 996 bar is stiffer. Just a guess.This is somewhere the tuners could do something. It would be great to pull the PASM box, learn what it does in the way of control signals to the dampers (and the range of settings the dampers can achieve, say using a shock dyno) then start working with heavier springs and electronically controlling the dampers to stay fixed at whatever setting. And having those settings adjustable by the driver while moving would be even better.
It's a long shot, but hopefully one of the more technical people at one of the tuner shops will do the R&D and bring out a little black box with two nice, big clicking dials and maybe even a read out of the PASM sensor data. Maybe even feed that to a DL1 for example. Wishing and hoping and dreaming ... : )

zellamsee

I noticed that Pete Stout, the author of the Excellence GT3 review, stated that he has yet to hear (from Porsche) a full explanation of how PASM works. FWIW, there is a decent description of the mechanics of PASM (and PSM) in the technical section of the most recent issue of Panorama. Also, I just received the most recent Porsche AG Annual Report in the mail -- in it, they state that the PASM setting for the RS is "substantially the same" as that for the normal GT3.

mitch236

That's what I was saying. I think you misunderstood my comment about how late model Porsche's have been setup to understeer and this GT-3 seems to be opposite to that thinking (meaning the car was setup to oversteer).