[dhanni848]

Installing shocks and dampers this weekend. I am working on the preadjustment for the rear shocks. I have Koni yellows and no matter how I set them the rebound is super slow!

Is that normal, and will be different when on the car? I am pairing them with Eibach sportlines and am looking at setting 1 turn from full soft.

thanks!

[Kgolf31]

Rebound controls the rate at which the shock returns to original position. So, in this case the stiffer the shock is, the slower the shock will be to return to original position.

Also, don't forget you don't have 900 lbs worth of weight on the shock

[dhanni848]

Originally Posted by Kgolf31

Rebound controls the rate at which the shock returns to original position. So, in this case the stiffer the shock is, the slower the shock will be to return to original position.

Also, don't forget you don't have 900 lbs worth of weight on the shock

Since there is no weight on them shouldn't the rebound be fairly quick if set to full soft?

[ajsalida]

Couple of points to add. If they are new there is some stiction from seals not having broken in. Second point is damper force is roughly proportional to piston velocity through the fluid, and opposite to direction of motion. At very low piston/rod velocity, ie sitting outside the car, only internal gas pressure is pressing the rod up, so very slow velocity and little difference between forces no matter what setting.

If you really want to test it, put the top mount on the rod end, set it at near full soft, clamp one end (or have someone hold it) and pull on the other. Then repeat set to nearly full firm. You should feel a big difference.

On shocks that are broken in, you can set to full firm and the rod will barely move at all from being compressed, at full soft it moves much faster. But new there may be enough friction that it might overcome everything else. Also like engine oil shock oil viscosity is higher when cold, so thicker.

[dhanni848]

Originally Posted by ajsalida

Couple of points to add. If they are new there is some stiction from seals not having broken in. Second point is damper force is roughly proportional to piston velocity through the fluid, and opposite to direction of motion. At very low piston/rod velocity, ie sitting outside the car, only internal gas pressure is pressing the rod up, so very slow velocity and little difference between forces no matter what setting.

If you really want to test it, put the top mount on the rod end, set it at near full soft, clamp one end (or have someone hold it) and pull on the other. Then repeat set to nearly full firm. You should feel a big difference.

On shocks that are broken in, you can set to full firm and the rod will barely move at all from being compressed, at full soft it moves much faster. But new there may be enough friction that it might overcome everything else. Also like engine oil shock oil viscosity is higher when cold, so thicker.

Fair enough makes sense! I'll set them and see what happens.

[Teohenwhy]

Originally Posted by ajsalida

Couple of points to add. If they are new there is some stiction from seals not having broken in. Second point is damper force is roughly proportional to piston velocity through the fluid, and opposite to direction of motion. At very low piston/rod velocity, ie sitting outside the car, only internal gas pressure is pressing the rod up, so very slow velocity and little difference between forces no matter what setting.

If you really want to test it, put the top mount on the rod end, set it at near full soft, clamp one end (or have someone hold it) and pull on the other. Then repeat set to nearly full firm. You should feel a big difference.

On shocks that are broken in, you can set to full firm and the rod will barely move at all from being compressed, at full soft it moves much faster. But new there may be enough friction that it might overcome everything else. Also like engine oil shock oil viscosity is higher when cold, so thicker.

That is exactly how the Koni representative explained it to me when I called them inquiring about this issue ( non-issue ).