by 4est on Wed Jun 11, 2008 12:08 pm
I'm not set on the spring rate. I will decide that at a later date, with input from those more knowledgeable (pretty much everybody). What I am looking for is input on stroke length, so I can get the right length spring.
The springs that just came off it are H&R 6" springs (400 and 571) with a 280'ish tender. The full length of both springs was 9.25", including the collar. The front, at full droop would dislocate by about .25" (not enough to cause problems), and the rear was pre-compressed down to about 8". The front, when weighted, compressed to right around 8" also. So, when it took the shocks off, the rears show an overall, unloaded length of about 8" (a little over an inch of precompression) and the front springs were loose by .25 or .125" (out of a 9.25" stack heighth). Again, when the car was sitting, the springs measured about 8" front and rear.
I have been told by someone I trust to get the shortest spring I can. I like the ride height it's at (+/-), so I think the spring height setting on the shock is in the ballpark (+/-). So I am thinking a 7" spring for the front, with a 2.75", 85 lbs helper will keep the spring from dislocating at full droop, and be right at 8" when loaded. For the rear, I was thinking a 6" spring with the same helper giving me a.75" preconmpression and then a 7" loaded spring (+/-).
The problem started when I had the now defunct CENSORED put the shocks off their shopcar on my car. They talked about the progressive rate of the combined spring (blah, blah, blah..) What really happened (I'm no mathmetician, so don't take me to the formula) is that I got some kind of funky, progressive spring rate that never approached the 400/571 range and gave my car a ton of travel, especially noticed in the front. At the last TT, my car dived under braking and bobbed from side to side under lateral g so bad that a novice like me noticed. It performed better with the PSS9s. It also rubbed holes in the fender liner of both front wheelwells (pretty badly).
So: I need to know what springs to get, and will take all input under advisement. Spring rate, stroke, et al. For the pros, (Jae, Steve, Phil) what length spring would you spec for a HD Bilstein with a threaded ride-height adjustment for a 993?
My head hurts now, so I'm gonna go lay down.....