KSport Coilover spring rate questions

Sorry for the long post, I did a lot of searching and just cant find my answers.

I recently bought a used set of Ksport Kontrol coilovers. The first thing I noticed is that the ride was better than the stock squishy suspension. But the I noticed I could not tame down the bounciness of the ride. When I say bounciness I mean oversprung/underdampened type of ride. Using speed bumps I determined the bouncing was caused by the rear suspension. I set the dampenening to full stiff and made sure the springs weren't preloaded, but it didn't help. At speed if I hit a large anomaly in the road it feels like the back of the car wants to launch off the road during the rebound. I checked and they have plenty of dampening and are not blown. After looking at the Ksport website I noticed that they advertise the spring rate at 9kg. I thought that's way to much, I'll get some 7kg springs, but then on here every Ksport thread says that the rears are 7kg. My springs do not have any type of markings on them, all I know is that they are 180mm in length. Does this super bouncy behavior sound like something 7kg springs would produce? Anybody know how I could find out what my springrate is? I'm thinking about getting a set of 6kg springs now because I don't want to buy a set of 7kg springs if that's what I already have.

 

Any input would be greatly appreciated!

I'm not exactly sure what the adjustment for the damping on those coilovers adjusts, but typically it would adjust compression and rebound stiffness. What you described is a situation where the rebound is set too high. So, try dialing the struts to be softer and see if that helps reduce the rebound. Those springs might be too stiff for the damping range of the struts causing the car to be oversprung/underdamped like you said. I have ridden in a number of cars with coilovers and unfortunately the less expensive coilover kits use lower quality dampers in some cases causing a bouncy ride.

I thought that at first so I did try the softer settings, but it made it worse. If I hit a bump on the hard settings it takes the dampers two to three bounces to stop moving. On the soft setting it was more like five bounces. On soft it really feels like I'm riding on just a spring. I also thought about just adding a set of helper springs to the current setup, but they are more expensive than a new set of springs.

wow if it's that bad you might need to do a complete rebuild and then you could switch to softer springs along with it

how many miles since the last build?

The Ksports are not serviceable. I took the springs off and with them on the full stiff setting I can barely move the shaft by hand. The dampening is smooth and shows no signs of air bubbles or low fluid. I think I'll just get a set of 6kg springs and hope they help. Right now I have the stock struts with H&R springs on the rear. The car actually drives pretty well with just coilovers up front.