GoRacer

iTrader: (2)

DIY: How to adjust coilovers (correctly).

If you have a lower priced version (like JIC SF1's) then you should rais the springs as high as possible and then the proper way to adjust is to lower them. The reason for this is if you raise the car by the springs (how mine was done) then you will compress and preload them (wrong).

Rings are aluminum and spanner wrenches are steel, hence wrenches do not scratch. You can however sratch the rings if adjusted incorrectly.

1. figure out the hight of your springs (mine are approximately 7 & 7/8th")
2. If springs were touched then you need to expand them. It's easy to tell, there should not be scratches on the metal rings from raising under pressure. You can unlock the bottom ring then loosen the top ring to lower the spring untill it's loose. The tighten slightly. I tightened my springs to 7.75" hight. This keeps them tought but no preload.
3. The coilover is adjusted by raising/lowering the threaded pipe (not springs). Unlock the steel purch (bottom part of damper that threaded pipe goes in to) by loosening the third/bottom ring and raise it up. You will adjust by turning the two locked rings under the spring (top one). Since there is no preload, it should turn very easily and you won't scratch the rings.
Tip: You can double stack the wrenches which gives you more torque to adjust hight.
4. I adjusted mine to a total of 10" on the passenger side and 10.25" on the driver side. I weigh 200lbs and there is a 1/4" drop with me in the car. It will give you a floor to fender lip hight of 26" which is perfect for street use (25" for track). Mine was previously adjusted to 24.5" which is way too low (yes, 1/2" was enough diff' to scrape speed bumps). You will want to measure from the top of the spring (under pillowball mount) to the top of the female perch.
Note: Different brands may have different measurements. Mine are Buddy Club Racing Spec but these are good numbers for you to start with..
5. Expect it to take some time if doing it by yourself as you will most likely need to adjust every corner several times. Make shure you lock the rings and torque the lug nuts properly.
Tip: You can determine your weight drop yourself with a measuring tape (metal retractable) and a business card. Open the door and measure from the floor to the X on the scuff plates. Then sit in it and measure again. Use a business card sticking outward to line up with the tape. Pinch the tape where the business card touches and read measurements. Make shure you measured at the same point the second time. This isn't as good as corner weight but pretty damn good for free and doing it yourself.

purerx7

iTrader: (61)

wow nice write up! how do you like the ride on the JIC's i have no idea which way i am going to go, I really want a set of zeals but i am a poor college student so.

sereneseven

^ what are you talking about??

preloading a spring is not WRONG as you stated, in fact there are many reasons to preload springs the most most important is to maintain a known gap to the bump rubber also preloading can be used as a tunning parameter....also if your going to go so far as to buy a coil over why wouldn't you buy a proper set-up pad and corner wieght it...corner wieght is one of the most valuble and critical parameters of chassis set-up.

GoRacer

iTrader: (2)

There is no need to preload the spring (as per manufacturer) on my Buddy Club Racing Spec's.. Your coilovers may be different. Some require helper springs, mine don't. If you know of a reason to preload other then a track setup, please feel free to post a reply. There are others with alot more race experience then myself on this board and I welcome their responses as well. Only trying to share what i've learned.

I had JIC SF1's previousy (for question asked) and when they were lowered you lost travel. They were not valved well and when you preloaded them it seamed like the spings didn't move. With the FLA-2's you can adjust hight seperately from the springs as the reason for my thread.

Corner weight is important for a track setup but as I wrote above I compensated for my weight. Not as acurate but I was able to do it by myself and for free. I can allways corner weight adjust it at a later time.

GoRacer

iTrader: (2)

...moreover, if if your brand requires preload or if you need to do so for a race setup as you stated then that is independant of hight adjustment as the whole purpose of writing this thread. High adjustment should not be done by the springs. If you don't have a perch adjustable set then it's better to lower the springs then raise them which will increase preload as you adjust ride hight.

Black91n/a

The way I've always thought it should be done is to remove the springs, on one of each front and rear coilover, then install them with the wheels and tires, and adjust the shock body untill the weight of the car is supported on the bump stop and the tire just barely clears anything that it could rub on. Then install the springs and adjust the height to whatever you want using the preload. As stated, preload is not wrong.

This way you can go as low as possible without worrying about rubbing the tire on anything. If your ride height is considerably higher then it might be advantageous to raise the shock body to get back some droop travel, but other than that, that's how it should be done.

rynberg

Why preload is a good thing:

Springs are NOT perfectly linear, even the "linear" ones. The greatest area of non-linearity is at the beginning of compression. Using a slight bit of preload (hand-tighten the collar and then maybe 1-turn of the collar with the wrenches) brings the spring through most of the non-linearity. Too much pre-load will result in a harder ride. No pre-load equals springs rattling around when the car is jacked up.

The best procedure with independent preload/height coilovers like these is to set a little bit of preload first and then adjust the height collar to achieve the desired ride height.

GoRacer

iTrader: (2)

uhg, lost my reply. Anyhow this thread is how to adjust ride hight indepently of preload. If someone wants to explain how, why and for what purpose to preload then please do. Pictures would be helpfull. If you adjust or rather raise the car by the springs then you simultaneously increase preload. My 8" springs were compressed to 6". I have no tire rubbing issues on the inside (fender lip is something else).



Unlocking the bottom of the two spring rings and raising upward will increase preload.

GoRacer

iTrader: (2)

Thanks Rynberg
(that was very eloquent, unlike my explenation lol)

As I and Rynberg stated I loosened the springs all the way then tightened them taught (from 7&7/18" to 7&3/4") enough to stay put and not rattle. Too much preload makes the ride way too stiff and not streetable.

As I stated above on non independent preload/hight coilovers (SF1's foe example) you will want to lower the car rather then raise it otherwise you will unwillingly overpreload as you raise.

sereneseven

If you are going to go with adj. coilovers I don't understand why anyone would not then square the car up properly....

going off spring free spring length is virtually useless

the key is to have equall shock travel side to side on all four corners, to abtain this in most cases you will have to preload the springs to an extent do to springs being inherantley different also proper amounts of droop and bump must be maintained.

one of the best ways is to make a set of solid spacers made to proper length installed in place of the springs so the chassis can then be squared ( with the mechanical height adjusters be it push rods or in your case shock body base) once the car is level and cross weighted to baseline then you can install the springs and adjust the pirches to get back to your baseline

there are many ways to set-up a car I just feel that your method ignores many aspects of chassis set-up...for a steet car i suppose it doesn't really matter but than again i don't understand adj. coilovers for the street. but i don't agree with your statement or the manufacturers statement for that matter that preloading springs is wrong.

Black91n/a

Unless you're at maximum shock extension at rest, preload won't affect the ride unless you unload a corner. At that point increased preload will make the impact of the corner coming back under load more pronounced. When you move the spring seat, the shock extends, so you're not actually compressing the spring any more untill the shock goes to full droop.

sereneseven

^correct,

moving the RH with the spring pirch vs on say the shock base or push/pull rod is simply moving the bump gap and droop limit around aswell as RH untill you bottom out the shock at which time you will start to jack initial spring rate in.

DamonB

If you want to adjust coilovers correctly you need to know things like crossweight. All you're doing is adjusting ride height which merely makes the chassis ride at some height. The crossweights can still be completely out of whack.

You can't properly adjust coilovers without scales.

ptrhahn

iTrader: (9)

I don't quite understand the obsession with "preload" in springs, since they will "preload" as soon as you set the car down. It's not like they're at full extention until you hit a bump or go around a curve. What difference does it make if it happens by threadding the collar up, or by the schock compressing? Compression is compression. If you've got to squarsh the springs up just to make your car ride high enough, the springs are probably too long or too soft.

I also don't undertand the obsession with "loose" (un preloaded) springs. The only time you'd get enough suspension droop for the springs to be loose is when one whole END or all of the car is in the air for a period of time that would mean you have much bigger problems. If you've aver jacked one side of the car up, you know that you can't adjust the coilovers that way because they're still loaded... you've got to get both front, or both back, or all of the wheels up. When would that condition ever be present during any driving that won't be closely followed by an accident? So what if they're loose when you jack the car up? They fall right into place when you let it down again.

No, you can't get coilovers PERFECT without scales, but if you get the fender hights very even, the crosswieghts will be damned close. Mine were within 20-30 lbs after a garage eyeball (and tape measure) job.

DamonB

If the spring is too short you're losing suspension travel, most often droop travel.

Depends on what anti-roll bar rates you're running.

The suspension goes into droop more often than people think. Anytime the car rolls the inside goes into droop. Anytime the car brakes the rear goes into droop. Anytime the car accelerates the front goes into droop. Anytime one corner of the suspension encounters a dip in the track that corner goes into droop. If the spring and shock length aren't matched the load transfers can make abrupt changes.

There are instances where people want less droop travel. This is accomplished by shortening the shock, not merely shortening the spring. With the shock shortened the spring doesn't leave the perch and no shock bump travel is lost.

As soon as a spring leaves its perch then that tire is no longer contributing anything to the chassis. Note that the spring can be out of the perch and the tire not lifted from the ground. At some point the spring must settle back into the perch and tracks are not glass smooth surfaces...

Imagine one tire encountering a dip and it drops into the dip enough that the spring leaves the perch. This is very easy to do if that corner is already somewhat into droop due to chassis roll, dive or squat. Once the spring leaves the perch that tire is supporting no weight and is merely hanging from the car (even though it's still rolling across the road). The spring has fallen out of the perch, so when the tire encounters the other side of the dip and starts moving into bump the tire is not resisted by anything but the shock compression damping. The shock compression damping has been created with the idea in mind that there will be a spring helping it, but there's no spring helping when it's not in the perch! You've just lost control of the unsprung weight at that corner.

Another issue is that shocks adjust the rate of weight transfer but they must be moving to do so. When the spring leaves the perch the shock also quits contributing to chassis and suspension control (though the unsprung weight can make the suspension continue to fall towards the ground and keep the tire on the road) and the chassis no longer knows that shock exists.

GoRacer

iTrader: (2)

Adjusting ride hight (by yourself) is what I meant.

This was my point. Maybe I worded the title wrong? My springs were “over” preloaded and I’m sure there are other setups done wrong as well, hence the purpose of the thread. My springs were compressed with 2” of preload and that is wrong.

I thought I reworded that but I’ll try again. Adjusting height by lifting the springs is wrong. If you raise instead of lowering will you increase preload as mine was increased by 2” on a 8” spring. If your colivers don't indepentant adjust from preload it should have been extended before being put on the car then it can be lowered instead of raised to desired hight. You can now get independant hight adjusting coilovers for $1k instead of shocks and springs with a fixed hight for the same price.

I’ve had my previous setup corner weight balanced before. My car is not complete and my Buddy Club’s were brand new. I unfortunately didn’t get a chance to adjust them before the car went in to the shop (for 4 months sitting in the parking lot). If a well known rotary shop didn’t know how to adjust height without affecting preload then there are definitely more cars adjusted incorrectly and people that don’t know how as well. Once my car is completed then I can corner balance but I am still relocating the battery, adding body stiffeners (although titanium won’t weigh much), audio amplifiers, etc. I adjusted them myself with no help in my garage and paid nothing. I am sharing how to get a proper street height doing it yourself. For the same $100 I paid the rotary shop I could have had the car corner balanced by Zeal Motorsports. What I’ve shown can easily be done at home, thus saving the reader $100 for a more accurate corner balance if they deem it necessary at a later time.

If you guys want to get in to proper race setup, cross balance, corner weight, etc, that’s great. I’d like to read those comments myself, but I don’t think that can be achieved at home by yourself with common hand tools (Hence: DIY in title). Thanks for the input.

DamonB

But you also have "correctly" in the title.

If you're adjusting coilover spring perches and are not putting the car on scales to check corner weight after ride height is determined then you're not doing it correctly.

ptrhahn

iTrader: (9)

Yes, I know that's theoretically the problem, but I can't think of any driving situation where this would actually happen.

At least in the Koni/GC example (which is the most common one where springs are loose), you have to get wheels basically OFF the ground to get the springs loose. Since you can't brake hard (or accelerate hard) enough to lift either end of the car, it isn't an issue.... and as previously stated, lifting inside wheels, or one side of the car won't do it either.

I've been running them for years and never heard the springs drop under braking (you can when you jack the car up).

sereneseven

goracer, you keep saying that preloading or raising the the car with the spring pirch is wrong.....that is a false statement. the spring pirch is your adj. for where the shock rides in relation to the bump rubber and droop limit...its not a matter of being "wrong" its one of the most critical adjustments on the car, it sets the bump rubber gap and droop limit which are two things that will affect a cars loaded weight distribution more than almost anything else you can tweak with.

DamonB

A long carousel turn can show this, especially if its cambered.

What tires you running? How much grip are you making? The less grip the less weight transfer and therefore less chassis roll/pitch and less droop. A tire doesn't need be lifted from the ground for the spring to be out of the perch.

When jacking one end the tires don't leave the ground until the shocks run out of droop travel. If you can jack the car up and the wheels leave the ground just after the springs leave the perches then in fact the springs aren't really short and you're not going to be prone to experiencing problems.

aznpoopy

imo this forum would benefit from a coilover FAQ writeup covering everything from basic install; to concepts like preload, short case, etc.; to corner weigh and proper set up.

especially in light of all the kids nowadays who buy budget coilovers and then skimp out on a basic alignment.

ptrhahn

iTrader: (9)

285 Hoosiers with Big brakes.... 500/400 springs, PFS swaybars. It's really never been an issue... at least that I've ever noticed.

Like I say, there's no way for it to happen in a corner, because even if you jack one side of the car off the ground, there's still tension. The only way it COULD happen is if you were to be able to brake hard enough to get both rear wheels at enough of a droop to the point where they are nearly off the ground.

rynberg

What GoRacer is pointing out is more of a problem with coilover systems that do not have independent height and spring collars. On these systems (like the Ground Control), the only way to change the ride height is to change the length of the spring or to pre-load the spring a lot (more than an inch!). This reduces suspension stroke as well.

On better coilovers, the height and spring collars are independent and you can adjust ride height without touching the springs.

As far as drooping when the car is jacked up....my wheels might drop an inch with these springs....

sereneseven

^^hmmm I agree if you set a car up to have a ton of droop you probably will never get to full droop while on the track. but why would you? I will say that Idon't have a lot of time seting up an fd but on nearly every racecar that i worked on, droop limiting to various extents has been a major tunning aid and can unlease a ton of grip

Black91n/a

All this talk of adjusting height with the shock body alone fails to see what I've been trying to get across. When setting the ride height this way you can easily come into a situation where a large part of the shock travel is unuseable because it's all in droop, or it's below the level at which rubbing occurs.

When you set the shock body so that the car's weight is supported by the bumpstops just before rubbing occurs, and then adjust the ride height with the spring pearch, it maximises compression travel, and then you can set the ride height and not have to worry about wasted shock travel. Sure you might have a lot of droop travel, but that's not a limiting factor, adjusting the shock to give more compression travel will just cause rubbing and damage to the car and the tires. There are cases where you might want to raise the shock body beyond that when higher heights are desirable and you want to maintain a reasonable level of droop travel, but other than that the shock should not be touched.

You bought coilovers with adjustable shock bodies, why would you want to adjust them so that they give far less travel than is possible?

Also, with softer springs, running at very little pre-load can cause the shock to compress to a level where you've got minimal compression travel, and lots of droop travel, this will lead to a rough ride and bad handling as you'll be constantly pounding the bumpstops. Pre-load is a very useful tool in setting the relative amounts of compression and droop travel, leaving this adjustment stationary completely negates that advantage.

I'll be getting coilovers next year, and I'm lucky, because from January to August I'll be 10 minutes away from a freind of the family's house, and he's got corner weighting scales, a camber gauge and toe plates, so I'll be able to set the car up completely and figure out settings for a street and track alignment.