I've heard that all springs sag over time. Does anyone now how long before stock S2K springs sag?

 

Properly designed car springs do not sag appreciably. But if your car is still stock you could measure the distance from the pavement to fender lip and several of us can compare notes.

At the opposite end of the scale some USAF buddies noted spring sag in their KC135 tankers. This is the airplane that Boeing later marketed as the 707 airliner. Sag was due to the aircraft being always loaded to maximum fuel levels and maximum takeoff weight something that wasn't an issue with the airliners who are typically parked with no cargo and seldom approach max limits. I recall they may have had to use suspension jacks when parked in this condition (but could have dreamed that!).

-- Chuck

 

Would say 2 weeks from new to settle then all ok.

 

I most likely won't be measuring it as I'm rebuilding the entire front suspension and since I have to replace the shocks I thought this might be a good time to replace the stock springs. They have 19 years and 170k on them so I'm wondering if they might have sagged or weakened. I was looking to change them with fresher ones since I'm also replacing shocks all the way around.

 

Compare left to right. If they're about the same length, slap them back in.

Don't forget to clock your bushings after replacement.

 

I do see higher mileage S2000s sit lower than new. I think it's mainly because the shocks wear out over time and lose some internal gas pressure (OEM shocks are monotube). Similarly, the CR seem to have higher front height than the base car, probably due to a lot more gas pressure in there.

 

Shocks have nothing to do with maintaining ride height, that's all springs. The shock is just there to resist the speed of movement, not to limit the range of movement.

 

Our shocks are gas charged, and do add some very marginal amount of spring rate (though not enough to really matter). If that rate does add any detectable amount of ride height, you'd be measuring that amount in 16ths of an inch if anything at all. So you might as well consider it to be non existent.

As for CR ride height, many who have switched their base model cars to CR springs on their stock, non CR shocks, have noted excessive ride height, especially in front. These are the same however worn shocks they had with original springs. So any change in ride height must be coming from the springs only.

Therefore if CR sits higher, it can be concluded its likely also due to springs, not shock gas pressure.

Worthy of note, since the CR shocks are a different part number, the location of the lower spring perch may be in a different location than non CR. So ride height differences could also be attributed to a difference here. Again, not because of gas pressure.

 

A lot of sag in older cars is from bushings that are collapsing.

If you look under the car while its sat on the ground, you'll probably see your shock bushing isn't anywhere near center anymore.

Tophat isolators also get worn out over time.

Shocks lose gas charge and sink a tiny amount.

Springs sag another very tiny amount.

It all adds up.

 

My CR springs have not sagged any appreciable amount in 60k+ miles including bumpy AF Sebring.