What is perloading, what does it do and how dou you do it. i have tokico bules and eiback spring. can you perload them as well or is it just a coilover thing
thanks for you time

 

It only really applies to coilovers. It allows the spring to remain seated when at full droop (i.e. car off the ground). There's really no other point to it than that. Some countries (Germany for one) require it to be legal.

 

thanks what with the diff rate in spring what is better for what i see some people saying they have 10k in the front and 6k in the back (i think thats what they said)
can any one give me info on this.


coilover's some day

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by krys83 &raquo;</TD></TR><TR><TD CLASS="quote">thanks what with the diff rate in spring what is better for what i see some people saying they have 10k in the front and 6k in the back (i think thats what they said)
can any one give me info on this.


coilover's some day
</TD></TR></TABLE>10K Refers to the stiffness of the spring. the bigger than number the more stiff it is.

 

i gotta admit, im a bit puzzled at the whole big deal about preloading. seems like it all started when omni's came out and the instructions talked about requiring to "preload" the top nut. and the other user found such a big difference when he "preloaded" his omnipowers.

but the weight of the car itself preloads the spring already. and never have the numerous persons who used regular "slip over" GC or such complained about bouncing and requiring preload. maybe concerns over springs popping out, but that usually wasnt a problem either.

so, i gotta say again, im just a bit perplexed by it all and dont have an answer...

 

i think your talking about compressing the spring for installtion, but most times with coilovers and with most springs not compression is needed

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Honda_project98 &raquo;</TD></TR><TR><TD CLASS="quote">i think your talking about compressing the spring for installtion, but most times with coilovers and with most springs not compression is needed
</TD></TR></TABLE>

We know that

I`ll bring in a suspension and racecar setup expert from partsquest.com to explain this to you guys and answer any questions.

Ryan

 

vtecvoodoo has asked me to answer the pre-load question.

Pre-laod is only done on the bench, not on the car. It's the amount of tension on the spring whe the shock/damper is fully extended. No sloppy fitting springs means good pre-load.

I'll answer the double treaded adjustment in a minute.

 

Pre-Load vs Shock Length

Some people are under the impression and have been told that the shocks with the adjustable spring seat and the adjustable body length somehow adjust pre-load and make the care handle better.

Anyone heard this?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by partsquest.com &raquo;</TD></TR><TR><TD CLASS="quote">Pre-Load vs Shock Length

Some people are under the impression and have been told that the shocks with the adjustable spring seat and the adjustable body length somehow adjust pre-load and make the care handle better.

Anyone heard this?</TD></TR></TABLE>

i a nut shell this seems like what omni power or his re-salers push. he has failed to asnwer the question also

 

The funny part about this is its not complicated once expained. The hard part is explaining it in text. I'll give it a try in small segments so the posts are short.

First a few definitions for reference -

Spring seats - where the spring touches the shock
Adjustable spring seat - threaded body, collar, c-clips, etc used to raise/lower the ride height.
Lower body adjuster - Allows shock to be adjusted up/down between the lower mount abd shock body

cont...

 

The Lower Body Adjuster simply shortens or lengthens the shock body. If you raise this up, you need to lower the Spring Seat to get the ride height back to where you were. You haven't increased pre-load you have simply lengthened the shock body and reduces your compression travel.

If you lower the Lower Body Adjuster, you will have to raise the spring seat adjuster to get your ride height back. You have now shortened the shock body and increased your compression travel.

Ideally, you would perform a travel test to find out "Maximun Compressed Travel" for your combination of parts, and never adjust the Lower Body Adjuster again.

Hope this helps

 

Please explain maximum compressed travel, and why adjusting the spring seat would change ride height?
I think the thing with pre-load affecting ride quality is some people made the mistake of leaving a large gap between the spring and the spring perch/upper mount, allowing for a lot of play in the spring, which led to shitty ride quality. Combined with (what appears to be) a needlessly complex height and preload adjustment method, this might confuse people about the exact purpose of preloading.


Modified by Noob4life at 1:31 AM 3/11/2005

 

i know the picture is dark but see that gap? that has NO effect on my ride quality, as long as you DON'T run out of shock travel you will be fine.



Maybe the omnipowers NEED to have preload so that it doesn't run out of travel.

but you don't NEED to have preload to HAVE a good ride.

 

omni's and other systems with adjustable shock bodies, have limited shock travel, so you might need to preload the spring to keep from bottoming the shock. how much preload depends on the weight of the car and the rate of the spring.

 

Ok now I understand what you guys are saying.
But why leave that space?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Noob4life &raquo;</TD></TR><TR><TD CLASS="quote">Ok now I understand what you guys are saying.
But why leave that space?</TD></TR></TABLE>

becuase that is how it works, i want to be at that hight so i set the spring perch there and that give me my ride height.

 

when you are driving around, the wheels shouldnt ever get to full droop... if they did, the impact of coming down would possibly damage the car rally style.

USUALLY you've got a sway bar, meaning that while you are turning the outside wheel that compresses will transfer support through the bar to the inner (drooping) wheel, preventing it from reaching full-droop.

In essence, unless you off-road or jump hills in san-fran, having a loose spring at full droop should not be an issue... in fact, it helps make it easy to make adjusments to height without the spring pressure.




Modified by fireant at 10:31 PM 3/10/2005

 

you know, the sway bar point is an excellent point ive not thought of before. thats very true, as long as one of the wheels is on the ground, the other will not be allowed to be at full droop, at least certainly not as much as if both wheels were off the ground. and really, youre never two wheel, front end, jumping hollywood style...

 

With mcpherson struts that have "full" coilovers, (maybe double wishbones too, but I dont know) there is a lower seat that can be adjusted independently from the spring. You have a lower perch for the ride height (kind of like snap-rings on konis, but threaded) and you have a separate upper perch for the spring.

You can literally make it so the car is lowered, but the shock is fully extended and the spring is pressed down hard... loaded tightly and compressed...while the car is off the ground and at full droop. However, when this setup is put into use on the road the effective spring rate is increased greatly and it could damage the shock.

 

Is it true that if you were to compress a "500lb" linear spring 1 inch you would have to put 500lbs of pressure on it... then you'd need to put 1000lbs to move it 2 inches?

If that's true, then by using a full coilover and compressing the spring 1" against the topped-out shock, you've effectively made a 500lb spring into a shock-chewing 1000lb spring? The rebound pressure of everyday activity would be beyond what the average damper could handle (especially the typical quality of the "full" coilover dampers you can buy)

{Please tell me if I'm totally wrong on this}

 

spring rate doesnt change.

compress a 500lbs/inch spring 1" requires 500lbs. to compress it 1 MORE inch, 2" total, would be 500lbs more, or 1000lbs total.

you would not preload the spring more than the static weight of the car. (say if the weight of the car at that corner was more than 500lbs) if you did, the spring would be a brick, not a 1000lbs spring until the load on the spring was greater than the weight of car at that corner.


Modified by Tyson at 8:11 PM 3/10/2005

 

:headache:

I'm glad I'm keeping it simple. Very good topic though.


Modified by fireant at 10:31 PM 3/10/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fireant &raquo;</TD></TR><TR><TD CLASS="quote">:headache:

I'm glad I'm keeping it simple. Very good topic though.
</TD></TR></TABLE>

I think it's easiest to think about pre-load in terms of the force vs. displacement graph for the spring. When you pre-load the spring, you move the vertical force axis to the right. The y-intercept is no longer zero, and the spring won't compress until you apply a force "above" that of the pre-load.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fireant &raquo;</TD></TR><TR><TD CLASS="quote">:headache:

I'm glad I'm keeping it simple. Very good topic though.

</TD></TR></TABLE>

heh, think of it this way.. I used to have a set of tein flex's, which are the same adjustable shock body design as teh omni's.

now when I first installed them, the springs would compress about 2" up front under the weight of the car, and decrease my shock travel (which is very limited on this design of shock).

adjusting the lower shock mount would raise the car, but I could still bottom out the front shock on tight, low speed corners.

So I preloaded the front springs 1". this gave me 1" more shock travel because instead of the spring compressing 2" under the weight of the car, it only compressed 1" (and raised the ride height 1" as well). I then used the lower shock mount to lower the car 1" back to the original ride height. this helped a lot from keeping the shock from bottoming out.

I did something similar with the rears too, added some preload to gain shock travel. but adjusting these things is a major pain in the butt, since you have to undo the lower shock mount to make height adjustments.

EDIT: if you would like some good information on preload, there are a lot of motorcycle websites that cover this topic. It seems like a lot of moto-x guys use preload to help tune their suspension setups.