Hey Guys,
I have a 2012 MCS All4. Like I have done with many of my cars in the past, I want to lower the car, BUT, I also want a stiffer-than-stock spring. I have a lot of experience with springs, dampers and other suspension components for a variety of Porsches in the past and present. In my latest endeavor, I have pulled the entire 996 Turbo suspension out of my car and replaced it with a GT3RSR suspension. It was a big undertaking, but well worth it after driving the transformed car with the changes. Part of that change was to specify the spring rates for the rear and front separately based on my driving needs for both track and road driving.
So, here I am with this Countryman S All4 and I want to lower and stiffen it. It is my daily driver and I am not interested in coilovers since I will not be tracking it or autocrossing it. Since coilovers are out, it leaves me to two rational choices, the NM Engineeering springs and the H&R springs. I believe both are progressive. Both lower the car from 1.4" to 1.6". That is all well and good, however, I want to make sure the new springs are stiffer than stock and I found a very obvious absence of this information anywhere!!
When I specified the Porsche 996 Turbo springs (understandably for coilovers), I had a variety from which to choose. I chose 450 pound springs up front and 800 pound springs in the rear. They were not progressive. The choices were based on a suspension expert's recommendation and have proven ideal!
Springs are not rocket science. There is a simple equation for them. F=kx
F=force to compress a distance "x"
k=spring constant
x=compressed distance.
Plain and simple.
For NON-progressive springs, k is constant for the entire range of the spring compression. So, for instance, if the springs are rated at 200#, it would take 200# to compress them 1", 400# to compress them 2", 600# to compress them 3" and so on.
For progressive springs, k is no longer a constant. So, for instance, the specification could read "200-500-900" in which case, 200# compresses them 1", 500" compresses them 2" and 900# compresses them 3".
I have tried calling the two companies and, whereas NM Engineering gave out rates for the front and rear as compared to stock (Thanks Jerry), H&R remains tight lipped and "refuses" to release this information.
I am just trying to get a simple answer. Do I have to buy both and put them in a spring compressor to determine their responses/rates? And then return the ones that are less stiff? And then publish the results to help the community??
Does anyone have any insight into this? I would appreciate any meaningful responses.
Thanks!

 

is price not an issue for you?

I know the majority were using coilovers (such as Megan) just from the sheer savings. $900 for coilovers...set them where you want and never touch them again. Otherwise you'll be spending upwards of over double that when you need to replace the shocks along with the springs.