Hello, guys,

The track season ended last weekend, and now the mod season begins...

My car came with PSS9's when I bought it in 2006. The springs seem to indicate that the suspension was installed in 2002. The shocks need to be rebuilt, and I would like to stiffen the springs at the same time. Bilstein says that they can revalve the shocks as needed once I tell them what spring rates I intend to use.

I drive the car some on the street, but that is almost all highway driving. I do 4-6 DE's per year as an instructor. I am most interested in better performance there. The current springs are 255 front, 515 rear. They seem much too soft to me. I'd like to hear your recommendations for spring rates for this application.

On a related note, does anyone have a table to cross-reference Bilstein codes to spring rates?

Thanks!

Jon

 

from looking at the aftermarket options 400/600 seem like a good match stiffer but not rock hard like a 600/1000 would be

 

I've just put 670 and 800 on JIC Cross dampers and with full soft F/R it's not a bad ride on the street. I ran 600/800 with Cross 3 years ago on the track with NT-01's and it performed pretty well for otherwise stock suspension.

 

Jon, mine are 450/700, seems like they're doing the job at the track and the street ride is still good. I've heard that 600/800 is still a happy medium, especially if the shocks are tuned for them.

 

Thanks, Larry.

How did you decide on that spring combination?

Jon

 

For reference here are OEM spring rates for GT3's. Picked up from Rennlist.

FRONT:

996.1 GT3
PART NUMBER: 996 343 531 91
SPRING RATE: 35N/mm

996.2 GT3
PART NUMBER: 996 343 531 95
SPRING RATE: 40N/mm

996.2 GT3 RS
PART NUMBER: 996 343 531 97
SPRING RATE: 45N/mM

997.1 GT3
PART NUMBER: 996 343 531 95
SPRING RATE: 40N/mm

997.2 GT3
PART NUMBER: 997 343 531 94
SPRING RATE: 49N/mm



REAR:

996.1 GT3
PART NUMBER: 996 333 531 91
SPRING RATE: 65N/mm

996.2 GT3
PART NUMBER: 996 333 531 95
SPRING RATE: 95N/mm

996.2 GT3 RS
PART NUMBER: 996 333 531 95
SPRING RATE: 95N/mm

997.1 GT3
PART NUMBER: 997 333 531 93
SPRING RATE: 105N/mm

997.2 GT3
PART NUMBER: 997 333 531 95
SPRING RATE: 115N/mm


Also I wouldn't be surprized if one of the sets was the *or close to MY06-09 997 cup set considering they used the slick cup rain tyres.

FYI Cup was:
Fmain length mm - N/mm: 100-260 997.343.531.90
Ftender length mm - N/mm : 75–43 996.343.537.90
Rmain length mm - N/mm: 130-260 996.333.531.90
Rtender length mm - N/mm: 60-50 996.333.537.90

For those who prefer Imperial Horse Carriage units, just multiply with 5,709...

 

[quote=FAST FWD;3028876]Thanks, Larry.

How did you decide on that spring combination?

Jon[/quote/]

It was decided by Alex at Sharkwerks who put those springs with the set of Motons that I bought from him used. They were on his 996TT before I got them. The 600/800 springs are favored by GMG and Steve Weiner for track cars.