Originally Posted by
CraigMBA
That is a progressive spring! It is important to ask why the manufacture used one and went to the trouble to make such a difficult build and expensive piece.
The smaller pig tails at the end of the spring are there to keep the spring from falling out of the bucket. They are uber soft compared to the rest of the spring, but without them, any time you hit a big bump or jacked up the car and drooped that axle, the spring would fall out. There was no other cost effective option for the engineer to fix that situation.
I figured you would like that pic... clear and concise.
Originally Posted by
CraigMBA
Because they work the same way. What's the difference between a sway bar and a spring? Both of them are a piece of wire of a certain diameter and a certain length. You actually measure them both in similar way - compression for a spring, torsion for sway bar or a torsion bar.
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He is, but he's not. If you understand the biggest difference between the two of them is a torsion bar/sway bar wants to return to center when deflected from either side, a spring can only be compressed one way you're almost home free.
I was trying to relate it to something simple looking. It seems most are confused by all the coils on a shock spring... so i figured relating to a simple swaybar would help.
I mean... i could have thrown a curve ball and mentioned that a sway bar is actually dynamic... since it ties in BOTH sides of the suspension... lol
Originally Posted by
jbrooks39
I disagree with the statement above.
Spring rate, for a coil spring, is determined/defined by the following three characteristics:
1. Diameter of the wire (or cross-sectional value of the wire). In simple terms, when the wire diameter increases, spring rate increases.
2. Mean Diameter of the spring (mean diameter, or OD of the spring minus the wire diameter). When the mean diameter of a spring increases, the spring rate decreases.
3. Number of active coils. In general, active coils are calculated as two (2) less than the total number of coils as the first coil on each end of a spring is, in layman's terms, not of use, or in-active. As the number of coils decreases, the spring rate increases.
Regards,
Joe
1.
YES
2.
FAIL Lets look at one side of a swaybar... a simple spring. When you shorten the leverage points the rate doesnt change... you increase its efficiency. Lengthening the leverage points decreases its efficiency. The wire STILL BENDS (notice i didnt say torsional twist) AT THE SAME RATE.
This is relatable to a BB spring and why it feels 'plush' or more 'consistent' than a regular AE spring. The BB spring is less efficient at doing its job than the smaller AE spring (and also one reason why the AE spring tries to move off axis... which also addresses efficiency... but i digress). This is also why a shorter lever on a swaybar increases response... its using the same rate and doing its job more efficiently.
3.
FAIL "As the number of coils decreases, the spring rate increases."
Really? So... youre telling me you have changed your mind with your previously posted...
"... when the wire diameter increases, spring rate increases."
Im not even going to get into your active/inactive coil theory... ill just leave that for you to think about.
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As far as the amount of coils in a spring... you will notice as a general rule that the thicker the wire the less coils there are in a linear spring. Also as a general rule... the more suspension travel, the greater the number of coils that will be present in any given linear spring.
You will see mix matched versions of this in various applications. Trust me though... if wire diameter does not change... neither does the spring rate... regardless of the amount of coils present... or how they are linearly implemented.
All this over a $3.50 pair of springs.
I know you (and i say that collectively... not pointing any fingers) have been told over the years that 'this' means 'that' but this is an opportunity to get the facts straight... and get some real insight on why something works as it does.
Isnt that why were all on this site to begin with?
