broncow72 said:
Todd, you might know this, or if anyone else does please reply. The first lift I had on my truck was an oldschool K-S 2 1/2", I was able to jump my truck pretty well with good landing results but it was a bitch on the supermarket parking lot speedbumps. I later went with the JD coils and found that jumping was a serious no-no. Obviously the coils weren't able to handle the compression as well as the stiffer units. In my train of thought the coil is supposed to take the majority of compression and the shock is intended to handle the majority of rebound. Is this wrong? If not, who makes a good spring to handle the compression of serious racing applications like the SCORE series?
The old school K-Bar-S springs, that you mention, along with the old red Ranchos, Superlifts, Burbank Spring, etc. were all very stiff (Ranchos are 485 lb./in. rate) as you know, so they fared pretty well with compression on the jumps, as you noted, although they were too harsh for much else. And rebound control had to be terrible, considering the shock technology back in the day. Hence the move to the variable rate springs in the early '90s, which had their own issues. I became a fan of constant rate springs again in the mid '90s after we softened up the rates a bit from the old days.
I'm probably the wrong guy to be asking about the springs for racing applications since I've never actually raced in a coil sprung, solid axle truck, but my recommendation would be to hear what works for Chuck and go from there. Personally, I'd do constant rate springs, like maybe Chuck's "winch springs" for a certain lift. I'd be curious to hear what he uses. I just finished an article on the Moss brothers' Bronco (2nd highest in SCORE Bronco wins of all time) for Bronco Driver and they use a set of National coils, which are probably very similar in rate to what Chuck might use. Then I'd use a good bypass shock at each wheel for control and some tuneability and adjustability.
Todd Z.