Andi

Does anyone have information on the spring rates F&R on each of these four models, either direct from Porsche or from having measured the springs? Obviously don't care about the helper springs just the main springs.

Thanks!

Yargk

Off the top of my head:
991.1 and 991.2 GT3
45 N/mm front
120 N/mm rear

991.2 GT3 RS
100 N/mm front
160 N/mm rear

I forget what the 991.1 GT3 RS is

BTW, the rear is progressive. One person here said they "measured" it and got about 18% less than the 120 N/mm. It's not clear how far over the range of the spring they measured it. (Because if they did, they would have multiple spring rates, that is, they would say something like 100 N/mm for the first 1 inch, then 110 N/mm for the 2nd inch, etc.) So to get a good effective number it should be measured around the static compression the spring has with the weight of the car on it.

Another data point is that Tarett's sport spring kit for the 991 GT3 has rear linear springs at about 118 N/mm. I wonder if this is because the effective rate on the stock progressive springs is a little less than 120 N/mm at static load so these linear springs are actually "stiffer" under all by heavy dynamic compression.

FogCitySF

Would really be interested in the .1 RS spring rates. Recall on a previous thread not too long ago that someone said their rear .1 RS suspension did not have helper springs but that later versions did through a part update. Would be very interesting to know .1.1RS .1.2RS (w/helper spring) and .2RS

Vise

Interesting, would like to learn more about this... and specifically understand what constitutes a later production .1 RS.

FogCitySF

https://rennlist.com/forums/991-gt3-...l#post16006400

^ this is where I last saw it being discussed

Vise

Super helpful, thanks much. My car is April 2016 production so in theory it should have the updated setup. Will have to check it out when I have it at the shop in the spring for alignment + corner balance.

mdrums

Since there are different spring rates between the GT3RS and the GT3...I wonder if the shocks are built and damped differently too?

groundhog

Also the sway bars in the .2RS are slightly softer than those found in the .1RS.

FogCitySF

Not to open another can of worms, but I wonder if the addition of the helper springs is making the later .1 RS versions more .2 RS-like? ie maybe that's why we're not observing huge deltas in lap times between some .1 and .2 RS's???