A Simple Suspension Question

Can someone explain to me how a shock vs. a spring works in the suspension system? How does changing one vs. the other effect how the E46 handles?

Thanks.


Daniel

another question to ask is, does BMW warranty cover suspenions?

Originally posted by 10chi
another question to ask is, does BMW warranty cover suspenions?

perhaps that would be better asked in a new thread, rather than hijacking this one right from the start.

sure no prob. I just thought that it would be better than seeing 2 questions about the same subject in a row. Hijacking?

A very simple explanation...

Together, the shock absorber and the spring suspends and isolate the car from the road and determine much of the handling and confort behavior of the car. Individually, they perform specific duties. The spring determines and maintains the height of the car relative to the road while controlling the up and down motion of the suspension to an specific rate (compression/rebounding rate). Left at its own perfect physics, the spring will be rebunding forever if not limited. There are metal (spring and leaf shapes) and air (air or gas filled, electronically controlled containers) springs.

The shock absorber further controls the suspension movement by controlling at what rate the spring will compress and expand. And in increasingly more applications, the shocks can determine when to control that spring rate. In rapid lane changes or sudden braking the shocks can increase its compression piston stroke to limit body lean. Or can decrease its compression stroke for smoother highway ride.

The next time you see a car bouncing all over just driving down a smooth road or severe brake dive, you are seeing a car with worn shocks allowing the springs total control of the suspension.

www.howstuffworks.com is a wonderful resource for fundamentals like this. They often include both pictures and animations. If a picture is = 1,000 words, an animation is worth 1,000 pictures!

I really enjoyed the transmission & differential articles.

Originally posted by Technic
A very simple explanation...

Together, the shock absorber and the spring suspends and isolate the car from the road and determine much of the handling and confort behavior of the car. Individually, they perform specific duties. The spring determines and maintains the height of the car relative to the road while controlling the up and down motion of the suspension to an specific rate (compression/rebounding rate). Left at its own perfect physics, the spring will be rebunding forever if not limited. There are metal (spring and leaf shapes) and air (air or gas filled, electronically controlled containers) springs.

The shock absorber further controls the suspension movement by controlling at what rate the spring will compress and expand. And in increasingly more applications, the shocks can determine when to control that spring rate. In rapid lane changes or sudden braking the shocks can increase its compression piston stroke to limit body lean. Or can decrease its compression stroke for smoother highway ride.

The next time you see a car bouncing all over just driving down a smooth road or severe brake dive, you are seeing a car with worn shocks allowing the springs total control of the suspension.

A fine explanation!

Originally posted by rhenriksen
www.howstuffworks.com is a wonderful resource for fundamentals like this. They often include both pictures and animations. If a picture is = 1,000 words, an animation is worth 1,000 pictures!

I really enjoyed the transmission & differential articles.

Agreed 100% although I went there right after reading this post and came up empty. Odd, but I guess their site is a continual work in progress. Just thought I'd mention it to save anyone the trouble...

Great explanation from Technic!

Try this link too - I find it extremely useful

http://www.fernblatt.com/longhurst/s...ion_bible.html