I'm doing some comparative research, and would like to know if anyone here can tell me the spring rates for the following springs:
First, the stock S197 GT
H&R Race springs
Eibach Pro springs
Steeda Competition springs.

Thanks in advance

 

Hi steelcomp,

Did I reply to you on this? I forgot if it was you or another poster. Anyway I used to have it all written down a couple of years ago when I tested the springs on a spring tester. What I remember is that Steeda Sport and H&R Sport springstopped out at about 200lb. in front. Theywere softer than Eibach's Pro-Kit springs and Steeda Competition springs which were nearly identical at 230lb. and 225lb. on top. The Sportline springs were 40-45lb. heavier than the Pro-Kit spring rates front and rear but the car was botoming out before you get into the upper end of the spring rate of the Sportlines. Generally speaking Steeda's S197Competition springs were a good 15lb. higher at the rear than Eibach's Pro-Kit springs.

HTH!

 

Thanks F1..are these ratesfront and rear? We decided to start with 380# in the front, and 175# in the rear with the GC coilovers. After riding for about 20K mi. on the Sportlines and stock dampeners, these new springs felt soft, and the car didn't handle as well. I tried tightening up the shocks,(especially the rears)but that made the handling worse. I had gone the wrong way on the rears, and after reversing the changes, (more dampening, less compression on the rear) it's started to come around. I still think the springs are a little soft for ultimate handling, but after a few alignment sessions and getting ride heights squared away, I've got them dialed in pretty darn good. I can say now, that with the current springs, the car rides a littel better than with the Sportlines, (still a little bouncy) and is definately handling better than before. The push is all but gone, and it's got much better traction off the corner. Just needed to play with it a little. They sent me some new springs, which are (I think) 400# front, and 200# rear. (The fronts have a GC p/n on them, not the standard Eibach number, so I'm not sure what they sent me untill Monday when I can reach someone.) I also finally got the dyno sheets on my shocks. The fronts are 8611 1258 "race" struts. Also learned that the rebound dampening on them is NOT linear, so I'm well within adjustability on them, even with stiffer springs.