more suspension questions....

[chmercer]

coiuple of questions..

1. spring preload?on my coilovers (tein he) for the preload adjustment, i have adjusted the preload perch so that the spring dosent rattle around, just so that it stays firmly in place, but dosent compress. I was wondering how exactly is the best way to set this, or what is it used for in a racing application? I would guess that if i had linear springs, you could use preload to increase the initial spring rate, but i fail to see a use for this for linear springs. can anyone explain?

2. "increased stiffness" adjustment on shock absorberswhen you turn the adjustment knob/screw/whatever on any variant of aftermarket shocks, what exactly is going on inside of the unit to "soften" the suspension? because its not like turning the adjustment device to the soft setting lowers the spring rate or anything.

3. what is the difference between adjusting the shock towards "stiff" and getting a stiffer spring on a softer setting?

4. anyone know the cheapest place to get extended wheel studs and open ended lugnuts?

[Nismo_Freak]

coiuple of questions..

1. spring preload?on my coilovers (tein he) for the preload adjustment, i have adjusted the preload perch so that the spring dosent rattle around, just so that it stays firmly in place, but dosent compress. I was wondering how exactly is the best way to set this, or what is it used for in a racing application? I would guess that if i had linear springs, you could use preload to increase the initial spring rate, but i fail to see a use for this for linear springs. can anyone explain?

Spring rates require so much force to compress them a given amount of distance.

Ex. 8 kgf/mm - 8 kg of force per mm of travel

So if you exerted 6 kg of force (Ie. a brake rotor on the top) you'd compress the spring 1 mm. If you put another 6 kg of force on the spring you'd compress it another 1 mm.

So logic would tell us that preloading the spring means that it requires more force to cause spring compression. A linear rate spring obviously wouldn't do this to the same effect as a progressive spring as you noted.

2. "increased stiffness" adjustment on shock absorberswhen you turn the adjustment knob/screw/whatever on any variant of aftermarket shocks, what exactly is going on inside of the unit to "soften" the suspension? because its not like turning the adjustment device to the soft setting lowers the spring rate or anything.

Basically its an internal adjustment that adjusts the speed of the dampening rate. The "harder" the setting the more force is required to compress the damper and thus the more resistance to spring travel, which in turn effects the rate of which weight is transfered in a corner.



This illustrates what I'm saying.

3. what is the difference between adjusting the shock towards "stiff" and getting a stiffer spring on a softer setting?

The shock is there to dampen the movement of the spring. It makes it react slower or faster depending on the valve rate.

The spring is meant to control weight distribution changes in the corner suspension bump/rebound. Changing the spring rate will have a larger effect on the cars handling than adjusting the dampening rate.

So essentially the difference is in how the two work.

[chmercer]

oh thanks nismo. i noticed a typo in my first post that may have been confusing. i said

I would guess that if i had linear springs, you could use preload to increase the initial spring rate, but i fail to see a use for this for linear springs. can anyone explain?

but what i meant to say was

I would guess that if i had progressive springs, you could use preload to increase the initial spring rate, but i fail to see a use for this for linear springs. can anyone explain?

that might clear up my post a bit, heh. I personally have linear springs, so thats why i was having a hard time figuring out what to use spring preload for.

[Nismo_Freak]

You can use it to increase your initial spring rate, but it will have a linear rate of increase whereas the progressive spring will have an exponential rate of increase.

Code: Select all

Linear

|               /|            /|         /|      /|   /|/-------------------

Progressive

|         /|        /|       /|     /|   /|/-------------------

I hope these graphs come out right

[chmercer]

ahh ok that makes sense. i have always misunderstood the term linear spring then. i thought that it would always require the same 8kgf/mm or whatever to compress the whole way down, but i guess that means that it increases at the same speed all the way down the spring, instead of a progressive spring that would increase on a curve, as your graph shows. thanks for clearing that up.

[Nismo_Freak]

If that was the case your car would be better off with a Slinky for springs lol.

[chmercer]

haha ty for the :help

[Dori Dori]

One thing to consider is what the adjustment does on your strut. What I mean is, does it controll bound, rebound, or both? Not all struts are the same.

[Nismo_Freak]

One thing to consider is what the adjustment does on your strut. What I mean is, does it controll bound, rebound, or both? Not all struts are the same.

In his case, it controls both.