There is nothing wrong w/ my springs/dampers. I think its just a unique situation.

Out where I live, the concrete slabs have started to deform that when, during rush hour, traveling at about 40 mph, the car rocks like a ski boat going over some waves. When going at freeway speeds, its a reacts normally (slight bump). I'm wondering if it is because the dampers aren't able to damp the springs enough. Would upgrading to heavier duty dampers (like Konis) take care of this problem?

 

Any mass/spring/damper system has natural resonances. Sounds like the spacing between your expansion joints and the 40 mph speed must fit one of them for your suspension. Changing the suspension would probably move the resonance around, but that just means you would hit it at a different speed.

 

I get the same thing on some roads around here. Happens at 70mph ish though, above 80 or below 60 and the resonance goes away.

Not sure that dampers would help much (unless they're actually broken) - think you'd need to change the spring rates to stop it happening. As mentioned in above post though, you'll just move it to a different speed range by doing this.

 

Cool - thanks guys.