Im planning on getting some Tein Flex coilovers and was wondering how the ride changes when the spring seats are tightened or loosened, making the spring either shorter or longer. I konw that the ride height is adjustable by screwing the whole shock up and down in the collar but how does the ride change when the spring in compressed more or less?

 

Well as far as I understand suspensions, by preloading the spring you just make the ride rougher, or it may have no effect at all.

Unless you have linear race springs, most springs are progressive for comfort at light compression and gets much stiffer in a nonlinear progression the more it is compressed (beyond the linear increase). Your pre-compression bypasses the lighter comfort range. Since the weight of your car and cornering forces are the same for your car no matter what precompression you use, you aren't going to change the performance of the springs.

Alternatively, it's highly probably that you can't precompress the spring on the coilover farther than the static weight of the car compresses the spring... which means precompression has no effect other than making it harder for you to assemble the suspension for installation.

 

I believe the Tein Flex, as well as most coilovers out there, have the linear springs. I suppose that means that the spring rate remains the same throughout the compression zone no matter how far it was compressed in the first place. So my guess would be that the only thing pre-compressing the spring farther does is shorten the suspension travel which would be bad for everyday driver. Does this make any sense?