HenrikH

H. Do you still have these side members?
Also since there is a lot of knowledge around the GT3 suspension and subframe, I have another question.
Is there any difference between the sides of the subframes between the GT3/GT2 and the standard C2/C4/Turbo except the solid bushings? Is it possible to press out the solid bushings from the original GT3 frame and mount them in the C2/C4 frame? I've discovered yesterday a crack in my side member in one of the attachment points to the car. It's difficult to source a new one, and it is easier to find C2/C4 side members if they are the same.

Any one experienced this fault?

Best regards Henrik

Scuderia V

We did some comparison between 996 GT3RS uprights (on the left) and 996 TT/GT2/3 uprights (on the right).
P.S. Subframes both are 996 GT3RS

rbahr

Hi All,

If it helps,there are some measurements of 996 gt3, 996 GT3RS, and GT3 RSR suspension parts here: https://rennlist.com/forums/996-gt2-...n-der-gt3.html

Ray

996.1GT3CS

Hi,

Not sure if it has been mentioned in this thread before, and I have looked, but not found again.
But I recall reading some where in a thread that the "street" 6 GT3 and 6 GT3 RS rear side members has the same geometry/pick up points even if they are still different parts ( one point would be milling to get clearance to the lower control arm if I recall correct ). So the question is if anyone here has made measurements or have information on pick up points/differences between the two.

I might recall incorrect and that it is the front sub frames that are the same, except the milled clearance to the lower control arm..

In this thread it is mainly mentioned differences between street 6 GT3 and RSR rear side members if I have not misunderstood the information?

Trying to figure out if I will achieve the 6 GT3 RS geometry by fitting the 6 GT3 RS uprights (F&R) on 6 GT3 subframes (F&R)

Thank you in advance!

996.1GT3CS

Found in another 996 GT3 RS Suspension thread here on Rennlist:
"You need all four uprights and the rear side members that fit 8mm closer to the body of the car"

So the rear side members appears to sit 8mm closer to the body compared to the std 996 GT3.
If so, the next question would then be if also the pick up points are the same or revised?

Also found this in a document describing the 996 GT3 RS differences:
"Rear axle side sections track and camber eccentric, because the stroke of the track and camber eccentric have been increased the side sections in this area have been modified accordingly"

Not sure what to make out of this.

I anyone of you sits on the correct information it would be very appreciated!

Thank you!

powdrhound

I installed the RS rear side members. The pickup points appeared to be similar to the regular GT3/Cup ones but I did not measure it with precision. Some of the milling was clearly different. If I recall, the casting was different also. My advice would be to use the RS side members. Porsche didn't make changes just for their amusement.

996.1GT3CS

Hi, thank you for the reply.

I have continued to search for the answer and I believe that the bottom line of this is that people mix up the race car RS and the street car RS.

The race car RS and other versions of GT3 race cars, as also mention in homologation documents, has raised rear side members and different pic up points as well, different spec between different versions of the race cars.

But, the street 996 GT3 RS has, according to my findings, only increased eccentric camber and track adjustment, no revised pic up point locations. So to get the street 996 GT3 RS suspension geometry you "only" need the uprights.
With that said, the casting of the rear side members might be different and perhaps stiffer and/or lighter, but of that I have found no information.


Thank you.

rbahr

What you say is correct. There is a difference between the race RS and the street RS. Important to note that the 996 STREET RS was the homologation vehicle for the 996 RSR. With that in mind, a fair amount of the suspension parts (and some motor) are not what are normally found on the standard GT3. If you search under my screen name, some time ago, I published a list of the differences.

I will try and check tonight

Ray

powdrhound

Someone has emailed me regarding questions on the RS suspension here and my final settings. After running the car for a number of years with this set up we ended up with the following:

Spring rates: 1700lb front, 2100lb rear (tenders with a 38/62% 344lb/565lb front/rear block load)
Front LCA RSR trunnion pins: short (the shorter pin lowered the roll centers slightly which benefited turn-in on a wide body chassis).
Rear LCA RSR trunnion pins: medium
Ride height: 98mm front / 135mm rear
Tires: 997.2Cup 275/645 front, 315/680 rear (25.5"/26.9" diameter).

Godspeed !

Powdrhound, you are very generous with your knowledge and experience. All gained through a lot of effort. Porsche is new to me, but have been involved with BMW Motorsport, Schnitzer and Alpina from the BMW world. Gleened my suspension knowledge from them. All intense track oriented applications.

As you have stated, much of what I learned and shared in the BMW world from these race cars can not be applied to the street. Some, maybe but .............

Truly enjoying these cars with engine in the back! Learning quickly from people like yourself. Mine is a 1999 996 C2. Responds directly to alignment changes unlike any other car I have fiddled with. Love it!

Godspeed!
Dave

69911

Powdrhound: I wanted to verify the use of inclination and declination as it seems not everyone uses the same definition.
Is your use the following or the converse?
5 degree front declination means the outer part of the LCA (upright/wheel carrier side) is higher than the inner part of he LCA (front subframe mount).

Thanks

powdrhound

declination = outer part of LCA is lower