I had the H&R springs and they are softer than stock. You know this because it didn't beat the crap out of you in Sport Mode like the OEM's did. They were also a little more bouncy over dips at high speeds. But overall much better than stock ones.

 

has anyone had experience using both Eibach and H&R springs?

 

If you look at the H&R/Champion spring it is preloaded or partially compressed at the top. I believe this is the softer part of the spring, the "helper" to lower the car. The remainder of the spring is pretty stiff, this makes it a progressive spring by definition IMO. You see this exact same preloading on the OEM GT2/3/RS springs, also made by H&R.

 

ya i agree, i even called HR and they said HR springs are stiffer then stock, but fabryce from GMG says they are softer then stock who to believe.

 

Yes Doug you got a good point. The after-market springs for the Turbo that I've seen are progressive. You could tell by the variable distance between the coils (in linear springs the distance is constant). Progressive spring starts with one rate and ends with a second rate, like what cgng30 quotes for the eibach.

It would be educational for us amateurs -- and more fair for competitors -- if the whole story is told, not just x is stiffer than y. The whole story would be for example a graph similar to what's seen in the enclosed picture (article from PCA's Panorama, written by among others - an anesthesiologist -- must be too much free time LOL ). It would tell for example where during the compression of the spring that the rate becomes stiffer. If one spring, say H&R, is softer starting out but becomes stiffer later -- then is that bad? What if the designer of the spring MEANT for the spring to behave that way? Are you going to doubt H&R's engineers? Are stiffer ALWAYS better? I have lots of questions, but no answer.

BTW, I believe in the graph the springs are linear -- from the constant slope; every y lb moves the same x distance, etc. (Any pro lurking here please correct me as needed.)

 

are they used or new

 

used. less than 4k on them