just received, and installed my Omni power full coilovers. Instructions said to Preload the springs, but I DID NOT PRELOAD. you preload by loosening the top 19mm nut, and then you tighten the 19mm nut after you finish install.

what does preload exactly do? how bad is it to NOT preload?

basically, i want to know if not preloading will be a significant downfall or if it will cause me any problems.

 

Pre-load keeps the springs from becoming un-seated when the suspension droops down (like when you jack your car up off the ground). To pre-load your coil-overs, you just thread the lower spring perch all the way up until the spring is tight between it's upper & lower perches (with the shock fully extended). Then lock the lower spring perch into place with the second collar. Now you adjust the ride height via the adjustable lower mount. Once you've attained your desired ride height, you lock the lower mount into place w/ it's secondary collar.

You can add extra pre-load by loosening the top nut. This allows the lower spring perch to be adjusted slightly higher. Then once you've installed the shocks on the car, and lowered it to the ground, the springs will compress. This allows you fully tighten that top nut that had been loosened. Now even when your shocks are removed from the car, the springs will remain slightly compressed (just like OEM springs/shock)...

 

im running my omni sports un preloaded and they feel fine IMO. i did it to get my desired ride height. good luck

 

Ive already put the coilovers on the car. Can I go back, and PRELOAD, even thought it's after the install ?

Basically, will it do me any good to go back into the coilovers and "preload" ?

 

Yes you can go back and preload without removing the damper...

just twist the main collar until it is snug up against the bottom of the spring.

You should run very little preload as the height of the damper can be independently adjusted at the lowest collar....

Running as little preload as possible will keep your spring rate consistent....

 

if you dont preload, will it make squeeking sounds? on my driver side front..u can barely move the coils up and down. this is for GC coilovers on kyb agx's. for the passenger side, i can move the springs up and down like 3 or so inches. i can move the driverside maybe .5 inches..i am getting squeeking noises from my passenger side everytime i hit a bump or when the road goes up and down and requires my suspension to move up and down. this happens on my passenger front and back and it does not happen on the driver side.

imagine 2 people have sex on a old squeeky matress. my suspension sounds like that.

 

Is there a reason why you have such a difference in preload between the two sides?

Is it due to a ride height issue?

Ideally, it should just be snug so the spring doesn't rattle around.... if it is corner balanced and there is a significant gap....this can be made up with tender springs.

 

hrmm, maybe i have to repreload them. they are @ 350lb/inch and 450lb/inch in the back

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94eg! &raquo;</TD></TR><TR><TD CLASS="quote">Pre-load keeps the springs from becoming un-seated when the suspension droops down (like when you jack your car up off the ground). To pre-load your coil-overs, you just thread the lower spring perch all the way up until the spring is tight between it's upper & lower perches (with the shock fully extended). Then lock the lower spring perch into place with the second collar. Now you adjust the ride height via the adjustable lower mount. Once you've attained your desired ride height, you lock the lower mount into place w/ it's secondary collar.

You can add extra pre-load by loosening the top nut. This allows the lower spring perch to be adjusted slightly higher. Then once you've installed the shocks on the car, and lowered it to the ground, the springs will compress. This allows you fully tighten that top nut that had been loosened. Now even when your shocks are removed from the car, the springs will remain slightly compressed (just like OEM springs/shock)... </TD></TR></TABLE>

thanks..this clears up my PRELOAD noob.
so i guess preload with loosening the top nut is better!?

 

what do u guys mean by perch?

so, do i raise my car? move the gold things on gc's all the way to the top, so my car is raised at normal height or above normal height, then i lower my car, then i tighten the top nut to add preload? then i would jack up the car again and move the golden wheel down to lower the height of my car?

 

from what i know..you cant preload Coils&Shocks combo..

 

We need some diagrams....

the way I see preload is with the top nut fully bolted down.....then collar/perch right below the spring is snugged up against the spring so it isn't allowed to move around....

That's how preload is set.... if the spring dangles around or is loose when you jack up the car...there is no preload....

preload on stock dampers can be "adjusted" by loosening the top nut on the tophat.

 

that is odd because my top nut is bolted down about the same length on both sides, but i have a lot of free play on the passenger side.

 

I would suggest that you bolt the nut as far down as you can.....

and then adjust the preload via the perch below the spring....

adjust the height of the car with the lowest perch.

 

Look, without loosening the top nut, there isn't going to be ANY real pre-load. Pre-load refers to tension on the springs BEFORE they are installed (like stock). If you just snug the lower spring perch up all the way by hand, you haven't really added ANY pre-load (allthough the effects are the same). The only difference when you loosen the top nut, will be a slight increase in shock compression stroke (wich is a good thing on a lowered car).

The fact of the matter is, if you can't follow the instructions provided by the manufacturer, you shouldn't be doing the install (not directed at anybody in particular). Honestly, preloading is the only advantage that these types of coilovers have over a regular shock/coilover-sleeve combo (valving or spring rates are cetrainly not better). If your not going to use it, you have just wasted your money...

How to add proper pre-load to an installed Omni style coil-over shock:
-Jack up car
-Place on jack stands
-loosen top nut the described amount from the instructions (don't let the nut hang off the shaft)
-spin your lower spring perch ALL the way up until it's tight against the spring
-lock it into place w/ the secondary locking collar
-lower car back to the ground (the car now adds the pre-load by pushing the upper mount down onto the spring)
-tighten top nut all the way down (locks the pre-load into place)
-raise car back up & place on jack stands
-unbolt lower shock mount from LCA
-twist lower shock mount to desired ride height
-lock it into place w/ secondary locking collar
-Repeat all this on the other end of the car

PS: Ground controls, or any other coilover sleeve cannot be adjusted like this. Since the shocks require an adjustable lower mount...

 

pre load DOESN'T DO **** TO THE PREFORMANCE OF YOUR suspension, there is no NEED to do it.

THE ONE and only purpose SHOULD BE only to keep the spring from moving around.


IMO and from the little bit i have looked at omni power coil overs the preload helps insure that you wont bottom out the shock internally. (IE there is relitivly limit shaft travel.) But i wasn't able to really take them apart and look at them so im not 100% sure.

I really don't under stand why they don't just come with a fixed spring perch and the adjustable lower shock mount, that way it would insure that the coil overs have proper "pre-load" that some people think is OOO SO important.

Now im not saying keeping the spring seated 24/7 is bad, it is a good thing, its just thats all preload is good for, keeping the spring seated 24/7.


The debate has happened many times and the answer is still the same (what i said above).

And steve has NEVER explained why it seems to be so important.


SO will NOT preloading you coil overs effect preformance? no it should have ZERO effect on pperformance, now if the preload insures that the shock will not bottom out internally then yes it will effect preformance but preload SHOULD NOT BE used for this perpose.

 

94eg! good post

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">...now if the preload insures that the shock will not bottom out internally then yes it will effect preformance but preload SHOULD NOT BE used for this perpose.</TD></TR></TABLE>

More importantly, it keeps the shock from bottoming out EXTERNALLY. It is similar to using extended upper mounts (like the GC top hats). When you lower the car back to the ground with increased pre-load, the shock doesn't compress as much when the car settles because of the preloaded spring pressure (leaving more usable compression stroke). It also limits suspension droop wich can be a good thing for drag racing (like using limiting straps).

Don't get your panties in a bunch about it. the fact is it does have different effects on your suspension other than keeping the spring seated. The real question is "how much of an effect in those different areas" (droop limiting & added compression travel). Those are the questions I cannot answer. I'de wager the reason the OMNI guys cannot explain how/why it works, is because they just copied the design from someone else...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94eg! &raquo;</TD></TR><TR><TD CLASS="quote">

More importantly, it keeps the shock from bottoming out EXTERNALLY. It is similar to using extended upper mounts (like the GC top hats). When you lower the car back to the ground with increased pre-load, the shock doesn't compress as much when the car settles because of the preloaded spring pressure (leaving more usable compression stroke). It also limits suspension droop wich can be a good thing for drag racing (like using limiting straps).

Don't get your panties in a bunch about it. the fact is it does have different effects on your suspension other than keeping the spring seated. The real question is "how much of an effect in those different areas" (droop limiting & added compression travel). Those are the questions I cannot answer. I'de wager the reason the OMNI guys cannot explain how/why it works, is because they just copied the design from someone else...</TD></TR></TABLE>


Unless Omnipower works differently than any other coilover with a threaded mounting cup, all the preload-instructions are doing is moving the shock tube up or down the mounting cup...it has no effect on the length of shock piston travel.

 

-spin your ***lower spring perch*** ALL the way up until it's tight against the spring
-lock it into place w/ the ***secondary locking collar***

OK, good step by step. but when you say the Secondary locking collar, are you referring the the LOWEST/LAST peiece on the whole coilover?

from your directions, this is how i see it....

o &lt;---- top 19mm nut
8 &lt;---- spring area
8 spring area
- &lt;---- first spring perch
- &lt;---- locking/2nd spring perch
- &lt;---- locking perch
!! &lt;----last longer/collar peice
!! last longer/collar peice


So...I would take the 2nd to last/2nd lowest piece and raise it all the way up to the spring, then take the lowest/the last peice and raise it up all the way? so basically, i should loosen that top nut, SLAM the car to the lowest setting. then adjust the height from there?

?? ??

 

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


Unless Omnipower works differently than any other coilover with a threaded mounting cup, all the preload-instructions are doing is moving the shock tube up or down the mounting cup...it has no effect on the length of shock piston travel.

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

Think about it, by moving the shock tube DOWN while everything remains in the exact same place (lower mount/spring/upper mount/ride height), you are increasing the amount of shock piston sticking out of the body. If you do this, you clearly increase the amount of available compression stroke & decrease amount of available droop stroke. Why is that so hard to understand? It makes perfect sense to me...

Here is a quick illustration...
The bottom coilover has the shock body (green) moved up in the mount (red). This leaves you with less piston available for the compression stroke. If you look at the top coilover, the body (green) is moved way down in the shock mount (red), leaving much more compression stroke. The whole time the spring perches (blue) stay in the same place relative to the chassis...



Modified by 94eg! at 1:57 PM 5/26/2005

 

That's obvious to me....you lost me where you equated this with preload...

You want to adjust the ride-height in double adjustable coilover setups by spinning the whole assembly into or out of the mounting cup, which retains the shock travel. Just like in your illustration.

The preload is set with the top perch, which will have no effect on shock travel if the ride height remains constant.

For example, lets say you want to pre-load the spring an inch...(lets not go into reasons why you'd want that in the first place)....you'd move the upper perch an inch, and you'd also have to screw the whole assembly into the mounting cup an inch as well, since you want the ride-height to be constant. Hence the shock piston location is unchanged in the shock-tube.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">For example, lets say you want to pre-load the spring an inch...(lets not go into reasons why you'd want that in the first place)....you'd move the upper perch an inch, and you'd also have to screw the whole assembly into the mounting cup an inch as well, since you want the ride-height to be constant. Hence the shock piston location is unchanged in the shock-tube.
</TD></TR></TABLE>

The shock piston (grey) IS in a different location inside the shock tube (green). My picture shows the exact same adjustment you just described, but the piston is clearly sticking further out of the body after it has been done!!!!

 

sigh...i don't think you're completely reading what I'm writing, and your own pictures are confusing you. The pictures you have don't have anything to do with pre-load on the spring, they have to do with the two ways of adjusting ride-height in double adjustable coilovers.

You could have both situations without any pre-load on the spring, pre-load is separate from what we're both talking about here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94eg! &raquo;</TD></TR><TR><TD CLASS="quote">
The shock piston (grey) IS in a different location inside the shock tube (green). My picture shows the exact same adjustment you just described, but the piston is clearly sticking further out of the body after it has been done!!!!</TD></TR></TABLE>

Your picture does NOT show the pre-load adjustment taking place, it shows a ride-height adjustment taking place. One using the lower perch, the other using the upper perch.