It is not specific to any spring/shock combination. Even good expensive name brands could be setup to blow out the shocks. It has to do with spring rate and how the shocks themselves are valved.
OE shocks are valved to only be used with springs with a rate less than
around (guesstimate)250lbs/in and a reasonable ride height. A lot of aftermarket springs have rates higher than that and drop the car enough to reduce the amount of shaft travel.
The basic job of the shocks is to
control the movement of the suspension. Without the shocks, the car would bounce almost uncontrollably and unpredictably. Take a spring on its own and bounce a weight on it, it'll compress then decompress continuously until eventually the spring loses it's energy and comes to a rest. This is pretty much what happens when the shocks are blown, though on a smaller scale since energy is being absorbed through other suspension components so it's not necessarily crazy. Essentially the shocks are no longer able to control the movement of the suspension. This can potentially be dangerous if you're an idiot and drive around with all 4 shocks blown. You could easily lose control of your car..
When you use aftermarket springs with a much higher spring rate than the OE springs on OE shocks, the shocks are now under-dampened. They can still control the movement of the suspension, but not at an adequate rate. The shocks basically can't keep up with the rate at which the suspension is moving in order to control it properly. So you end up bouncing around MORE than you really should. This also hurts performance if you are racing.
What is leading you to say your shocks are blown, other than time? There is really no specific time line, spring rate, ride height, etc.. that will determine when a shock will blow out. It is just known that if the spring rate is too high for the shock, it will eventually blow out sooner than it really should if you used the proper spring rates.
Everyone's definition of a comfortable ride is different. I would find it hard to believe that springs with a 2.5" drop on OE shocks would be any bit of a comfortable ride.
In order to be that low, the springs SHOULD have a significantly higher spring rate. Since the Skunk2 springs lower about the same as the springs you have, lets compare. The Skunk2 springs have a rate of 500lbs/in front and 300lbs/in rear. Note that these springs are PROGRESSIVE, just like yours likely are. This means the initial rate is softer and progressively gets stiffer to the 500/300 numbers as you corner hard. The reason the Skunk2 springs have such high rates is because they lower the car so much. The lower you go, the higher the spring rate that is needed to prevent the car from scraping, sagging, etc..
I can only assume that the springs you have would be progressive, which is more likely why the ride may seem decent to you. The rates are also probably lower than the Skunk2 springs, which also helps with ride quality. However, I highly doubt the springs you have would have rates lower than say 300lbs/in. Being that low and have such a soft rate, you would definitely be bottoming out your car and slamming into your bump stops. Which if that's happening, I wouldn't consider the ride to be smooth.
I can tell you that I have Tokico lower springs on OE 140k mile shocks on my daily driver '99 Civic. Lowers the car probably around 1.6" all around. I am unsure of the rates for these springs, but they are definitely not a whole lot stiffer than stock. Best guesstimate would be something like 200-220lbs/in front and 115-135lbs/in rear. On some big dips in the road, the car will bottom out and hit the bumps stops, which I did cut down. The ride quality is excellent, if I didn't tell you, you probably wouldn't know it's on aftermarket springs. Everyone who's ridden in the car hasn't said anything lol. For your car to be almost a full inch lower than mine on OE shocks, I would find it hard to believe that it could have nearly the same spring rate and not bottom out all the time.. All while maintaining a decent ride. Just doesn't make sense.
There are a few ways to determine if a shock is blown. One is to obviously feel the car when driving it. If the car is bouncing around oddly and feels "loose", chances are a shock(s) are done. Another is to visually check by looking at the shocks. If you see fluid surrounding the shocks, that means the seal for the shaft has gone and there is no longer fluid within the shock to control movement. Another easy way is to do the "Bounce Test".
"BOUNCE TEST
Before you visually inspect the suspension, do a simple bounce test to tell if the shocks or struts are weak. A bounce test is not a very scientific test because it requires a certain amount of judgment. Worn shock absorbers and struts that allow more than one or two gyrations after rocking the bumper up and down and letting go have reached the end of the road and should be replaced. But what about the "marginal" dampers that still soak up some of the bounce, but not as well as new ones? They should probably be replaced, too, to restore like-new handling and ride control."
Taken from this website.
http://www.aa1car.com/library/ride1.htm <- plenty of good info. Read it.
When a shock is blown, it is usually pretty noticeable. Even more so if you are using aftermarket springs. And I doubt your rates are really comfy, though that is subjective...
Spring rate plays a role in determining how your ride quality will be, but that's just one part of it. The proper shocks matched to the spring rate you use really determines ride quality. There are other factors such as how low you are, what other suspension components you are using(ie: hard bushings, spherical bushings, etc..). Tire size, sidewall stiffness, and compound also aid in ride quality.
You are right with the dampening of the shocks not having a drastic effect on how stiff the ride is. However, say you keep your OE springs and throw on Koni Yellows. You now have over dampened shocks for the spring rates. It is OK, not as bad as having an under-dampened shock. BUT, you will notice the ride quality suffer such that it feels like the suspension "hits harder" when you hit bumps/dips in the road. So again in that sense the shocks play a key role in ride quality.
But, generally yes, the higher the spring rate, the less comfortable the ride
should be.
/long a$$ reply
