***Coilovers...Preload?????***

[upSLIDEdown]

Ok, so I have some new coilovers (dual height adjustable). I've searched 2 forums now for answers, only to find a bunch of different responses. My question is should I preload the springs or not? I've heard no, just snug the perches up to the bottom of the spring, I've heard only preload the front... I dunno what to do. Anyone know for sure what's the best way to do this? And how much to preload (if any)?

Thanks guys!
Bryan

[Ian]

it depends on how stiff you want it


preloading is good if your car is really slammed and you want to maximize stiffness, or you're cornerweighting your car

but that's about it

[chmercer]

lower the car slightly more than you want, and preload it back up to the height that you want. 1/4 to 1/2" of preload is a good generalization.

[upSLIDEdown]

So then preload all four corners just a little?

[atom]

It doesn't matter one bit for most people. Spring pre-load is one of those things where if you have to ask if you need it, you don't need it.

[upSLIDEdown]

It doesn't matter one bit for most people. Spring pre-load is one of those things where if you have to ask if you need it, you don't need it.

That's one of the dumbest things I've ever heard. Just because I don't know a lot about preload doesn't mean I don't need it. I'm trying to find out all the info possible about it, so I know the best way to set up my suspension.

And for the record, this car will have every other major aftermaret suspension component also. 18x8.5 and 18x9.5 +25. S13 by the way, and it will be tucking a little tire in the rear, and sitting even with the tire in the front, or maybe tucking a little, we'll see.

Bryan

[Ian]

which coilovers did you buy?

i hate to break it to you, but you might not be able to get that low depending on which ones you got

[atom]

That's one of the dumbest things I've ever heard. Just because I don't know a lot about preload doesn't mean I don't need it.

Uh, yes it does.

What you don't understand is that pre-loading a spring makes such a miniscule difference in handling that the only people that should even really care about it are the people who need to shave off every single millisecond off their lap time.

But hey, maybe I'm wrong. Lemme ask you this: When you are about to head to the track are you the type of person that will adjust camber,caster, and toe to suit that particular track? If not, then you don't need to worry about pre-load.

[upSLIDEdown]

That's a much better response. I will be the judge of whether or not I need it though. If your statement is true (about such a miniscule amount of difference), then I probably shouldn't worry about it. This car is being built to the hilt, so I don't want to skimp on anything, that's why I'm trying to find out a little more about preload. I've seen other posts that say corner balancing is a very good investment...what do you guys think about that? I have a friend that has a set of scales, is that something I can do my self?

[chmercer]

^^^^ wtf are you talking about man? preload drastically changes the feel of the car.

[upSLIDEdown]

^^^^ wtf are you talking about man? preload drastically changes the feel of the car.

See what I mean... You and a lot of other people say it definitely changes things, I'm just trying to find out if there's a certain "better" way to do things. I just finished unassembling them, cleaning them, and reassembling them with no preload, just snug.

If my thinking is correct... If I need to, theoretically if I preload it some, then I can get them lower via the lower bracket... right?

Bryan

[atom]

How so? Changing the spring pre-load on a coilover with a linear rate spring only really affects the droop.

I'm too lazy to type it all out but if you want to learn more then go to honda-tech and search for "preload" or "droop". A lot of people there with a lot more knowledge than me and a lot more racing experience than me (including Lee Grimes @ Koni) say the effects of spring pre-load are minimal at best so I choose to listen to them........

[scarecrow]

Question, Has any one ever scaled a car? Ever thought about it? How do you adjust weight? My guess would be to adjust preload on your coil springs. In my limited knowledge about setting up cars (as suggested by my low post count), would think that the primary reason to have coilovers is to have the ability to dial in your desired setup. Personally I have a moderate amount of preload up front and no preload in the rear to encourage squat for weight transfer and traction. My advise is to experiment. Good luck. :bow:

[upSLIDEdown]

Yes, preload is used for corner balancing.

Ok, it seems that people on here know about as much or less than I do about preload. So far, I've come to the conclusion that preload does stiffen the feel up, even on linear springs. No, it doesn't change the spring rate, but it does give a stiffer feel and here's why. If the rate is 300lbs/in and the corner of the car weighs 600lbs, then the spring will compress 2 inches when the car is on the ground. If you preload the spring 1 inch, then it will only compress 1 inch, for a total of 2 inches. If it's preloaded 2 inches, then it won't compress at all with the weight of the car. I still have a lot of learing to do, but that's some of what I've gathered thus far.

Bryan

[Dousan_PG]

why not try and see what you like? dont depend on other people
i do stuff ilike w/ my coilovers to get the setting i want
fuck everyone.

[atom]

Thats not how it works on a linear spring. pre-loading a spring is an ADDITIONAL force.

[upSLIDEdown]

Hmmm, well then I dunno, I still need to do more research. Guess I'll start with no preload and see how I like it...

[upSLIDEdown]

Found this on SPL Parts' website:

"There are 2 ways to adjust the coilovers to achieve the desired ride height. One way is to move the spring perch up and down, the other is to thread in/out the lower bracket to shorten/lengthen the coilover assembly.

When you move the spring perch upwards, you are compressing the spring. As the spring compresses, it exerts a force on the upper mount of the coilover. So when the weight of the car is placed on the upper mount, the weight would have to overcome the spring tension in order to compress the spring any further. Placing the spring under tension is called "pre-loading" the spring.

Moving the spring perch upwards (preloading) raises the ride height, moving the spring perch down lowers the ride height. To adjust the spring perch, make sure lower bracket is tight (lock nut is tightened against bracket), then use spanner to rotate the perch. Put a hand on the shock body to make sure just the perch is moving, and the shock itself is not rotating. Tip: Make a mark on the spring perch so you can tell how many turns you are rotating the perch.

The other way to adjust the height is to shorten or lengthen the coilover assembly. You can do this with the coilover installed on the car as long as you do not have too much preload on the spring - loosen the lock nut on the lower bracket, then grip the shock body and twist the shock body itself. You can also place a mark on the shock body to count the number of turns you are doing. You want to make sure your left and right coilovers have the same assembly length.

Which method should you use? Preloading the spring allows more stroke/travel for the shock, which is very important; if the shock stroke/travel is too short you will be constantly hitting the bump stop. However, preloading the spring too much can create problems - it would become easier for the tire to lift off the ground when the weight transfers away from that corner, and it would also effectively increase the spring rate.

So ideally you want to preload the spring to where you get sufficient shock stroke/travel, and get your remaining ride height through the lengthening/shortening the coilover assembly.

Tip: You can use a ziptie tied around the shock piston to check the maximum stroke/travel - tie it round the bottom and when the shock compresses the ziptie will be moved upwards. If it reaches the upper mount you may not have sufficient stroke/travel."

[upSLIDEdown]

So it seems that preloading allows for more shock travel, and when you lower a vehicle you lose travel. So since I'm planning on going pretty low, I should probably preload it a little. Is my thinking correct here?

Bryan

[Ian]

i've found that preload did not affect my ride height

[upSLIDEdown]

From what I've read, it won't affect the ride height until it exceeds the weight of that corner... I dunno, I'm getting too many mixed responses and someone doesn't know wtf they're talking about. By the way, I just finished reading the long ass Megan Coilover thread and I'm curious if you're still running them. If so, how much do you have it dropped and can you go lower? Got a pic by chance? I met you at Ex. Nats at VMP but didn't pay any attention to ride height. I was the white guy (that got sick from the heat) with Adrian in the red S14 Kouki from Lynchburg.

Bryan

[chmercer]

See what I mean... You and a lot of other people say it definitely changes things, I'm just trying to find out if there's a certain "better" way to do things. I just finished unassembling them, cleaning them, and reassembling them with no preload, just snug.

If my thinking is correct... If I need to, theoretically if I preload it some, then I can get them lower via the lower bracket... right?

Bryan

oh sorry, my flame was pointing at atom.

also preloading to get the shock bracket to go higher dosent really work. since pretensioning the spring will make the spring push up on the car, raising it. so its kindof counter productive. the lowest a coilover will go is when you have the shock bracket bottomed out on the insert, and let the spring droop off the perch, just make sure you are careful when you lower it. this would be super retarded low with most setups however.

basically what i would suggest is try preloading the front a half inch, rear half inch, and both half inch, and just drive it around and see if you like it. makes the car feel like it has a higher springrate basically.

[redsuns3838]

if u had to ask that question in the first place i think you should leave it without preload at first. drive it around, get used to it, drive it a lil harder and get used to it and make ur judgement from there as for wut u want. you do plan on cornerweighting it right? so that everything is even instead of an awkward weight distribution. a measuring stick and counting rings on the dampers isnt going to make it even. its better to take it for alignment and corner balancing after the install. ok goodluck and outa curiousity what brand of dampers did you buy?

[MadScientist]

upSLIDEdown - Corner weight balancing is awsome if your going hardcore or full race. You have to have everything your going to have on the car already in its place including your but in the driver seat and position exactly (arms on steering wheel and all). Its more grueling for the driver thanit is for the techs doing the work. I have seen a 4 man crew and a 2 man crew working and it seems the 4 man crew gets it done faster... one person doing it would look like a Japanese Fire Drill. Were talking at least 2 hours... its not fun but worth it to some.

Naturally the Driver side is heavier due to the weight of the driver, and the front is heavier due to the weight of the engine. So Left Front, Right Front, Left Rear, and Right Rear is the greater to less than weight. Corner Balacing is not just your Coilovers eather.

You can learn alot just watching.
Peace
Drew

[sideview_180sx]

It doesn't matter one bit for most people. Spring pre-load is one of those things where if you have to ask if you need it, you don't need it.


As atom stated. You keep asking questions to figure out if you need it. Pretty much, if your spring rate is below 14kg, you don't have a full cage, composite panels and possibly doors, lexan or mylar window. and heim joints and sperical bearings that have replaced all bushings and links, and r-compound tires. Don't worry about it, because it work make enough of a difference for you to care.

Food for Thought, just have your perches high enough to keep the spring for popping loose, other then that use the lower bracket to adjust ride height.

OT: you won't be that low for long, only people who are like that are BH and scooter. Dammit use fucking google to answer your questions you t00L " spring preload defined" :lockd:

[upSLIDEdown]

As atom stated. You keep asking questions to figure out if you need it. Pretty much, if your spring rate is below 14kg, you don't have a full cage, composite panels and possibly doors, lexan or mylar window. and heim joints and sperical bearings that have replaced all bushings and links, and r-compound tires. Don't worry about it, because it work make enough of a difference for you to care.

Food for Thought, just have your perches high enough to keep the spring for popping loose, other then that use the lower bracket to adjust ride height.

OT: you won't be that low for long, only people who are like that are BH and scooter.

Well the cage isn't there yet, but it's coming. I have spherical RUCAs and toe rods, and boxed in stock traction rods. Every other bushing is poly. Plus nismo power brace, whiteline rear sway, nismo front LCA, new rear LCA/ball joint, subframe spacers, SPL TC Rods...there may be more, but I'm not remembering it. I put them on last night and just left the perches snug with the bottom of the springs, so they can't move, but no preload. Rear is tucking half the tire and front is tucking a little tire. I'll try to get some pics sometime soon. ;)

Dammit use fucking google to answer your questions you t00L " spring preload defined" :lockd:
:cj: :cj: :cj:

Thanks for all the input guys! This has been a very informative thread!

Bryan

[upSLIDEdown]

Just measured front fenders...610mm :)

[chmercer]

this is stupid. just play with it and see what you like, people saying to not worry about it are dumb. its totally noticable when you change the preload on an axle.

[nokuntrol]

Thats not how it works on a linear spring. pre-loading a spring is an ADDITIONAL force.

Sorry to bring this thread back to life. I SEARCHED and found this.

anyways...
If pre-loading a spring is an additional force, can you tell me which direction this force is coming from?

When the car is seated on the ground, there is a downward force acting on the springs (from the weight of the car). But for the sake of argument, let's assume the car in jacked in the air and without the weight of the car acting as a downward force on the coilover.

Now if you were to Pre-load the spring, there would be a net force of ZERO acting on the coilover.
If there were any forces acting on the spring, the spring would be physically moving along the Z-axis. Since there is no moment, we can induce that all the forces along this axis have cancled out (or Net force = 0).

So what really changes then? Since this is a linear spring, it doesn't matter how much you pre-load anything. 300ft/in is still 300ft/in after you pre-load 1 inch or 2 inches.

what I think changes is the stroke travel. By pre-loading the spring, you are actually limiting the available distance the stroke has to travel. -The spring will fully compress before you reach the end of the stroke. In affect, you are always using the upper portion of the stroke.

In my case, i do not pre-load since I like to use my full stroke of the shock.
I tend to get stuck on curbs since i have an open diff. The extra travel puts my wheel back on the ground.

If someone can tell me other benifits of Pre-loading, i would like to hear them. Specifically how pre-loading relates to ride quality/smoothness.

[nokuntrol]

After driving home and giving the topic more thought...
One benifit of having your spring pre-loading would be the increased speed of spring EXPANSION.

In the short instance that your springs need to expand (under heavy cornering) the extra pre-load would help increase the speed of expansion. Also think about driving over bumps and ruts in the road. I'm thinking pre-loading would provide a firmer and increased coilover response.

Note: this is different from spring rate as the amount of force needed to compress the spring 1 inch.

So to say that pre-loading doesn't make a difference is not true.

thoughts?

[nokuntrol]

Double Post. please delete.