Racerron

Does anyone know of a stiffer rear anti-roll bar for the RS and if not, what is involved in installing 997 Cup rear blade type bar.

NJ-GT

Do you mean the $10,000 blade type bar installed in the 997 GT3 Cup?

Do not add bar, add the right front/rear springs and balance it with the stock bars.

Carrera GT

The Cup bar isn't that expensive. The RSR bar is expensive (and completely different.)
I think it was still something like $3K just for the bar for the Cup. I forget, but I know it was enough to completely drop the idea.

And agreed, the solution is the right springs and dampers, the roll stiffness will be fine (and the car already "skates" so it doesn't need more bar.)

There's a thread by grussell where he has a nice setup using street JRZs and Hooter slicks with only 400/600 springs, which can't be much more than factory, but by his account, work well even with the extra stick of the slicks.)
https://rennlist.com/forums/showthre...&highlight=JRZ

grussell

400/600 springs did not work well enough for us. Too soft and we could not dial out the oversteer.

We are putting in 900/900 springs and 997 Cup Blade anti-sway bars right now. Testing will be done next week and I will report back.

Carrera GT

900lb in the front? That should be entertaining.
: )

grussell

That's what I thought. Many of the shops that I have been talking to are running higher rates in the front to fight the oversteer. The 997 cups have the same rate front and rear from the factory. We shall see what happens. It is easy enough to change springs until we find the magic balance. With 400/600 and the front bar full stiff, rear full soft it still oversteered like crazy.

Carrera GT

Have you looked at using a remote adjuster on one or both sways?

grussell

nah, blades are very easy to change.

Carrera GT

On a hot car, during a test session?

grussell

no problems here.

scss98

doesn't sound right to have equal rates front and back. you have all that weight and the wing in back so logically you need more spring in back. assume you played with camber and toe already?

NJ-GT

I agree. On high speed sweepers the car will push.

Grussell, what kind of static toe are you running at the rear? That might be the problem. Did you change the ride height?

Carrera GT

Keep in mind the car's front-rear balance is a lot better than a street car (the race car design allows them to move everything forward and in some cases, there's ballast to make up minimum car weights) and the race cars can run a larger fuel load and more rubber, so the combined effect is a lot more work for the front end. Still, 900 is getting up there for the rears, let alone the front -- the car just won't enjoy the street once it's running those kinds of spring weights.

NJ-GT

I currently run 450/650 on my 996. Moton CS at 2 clicks on bump and 3 on rebound. Happy car on the streets, more settle than stock.

I ran a set of 750/1000 2 years ago, and it was not that nice. Quite stiff ride, and slower lap times at my local tracks.

grussell

Agreed, and that is what we have done. We even moved the power steering pump to the front ala 997 Cup kit. I doubt it will be seeing the street again for a long time.

With a starting point of 900/900 we can test the car and adjust the front rates accordingly to balance the car.