Badmunky

Updated last on 11/25/2006 at 4:47am. Reson: Added pics and some new parts to the lists.

Ok this is long but read it all.




This is just something for reference for beginners starting, those who are new to the site, or those whole are lazy and don’t wanna use the search function.

Basically just a FAQ/Tutorial on lowering a cobalt in specific. Most things I write from experience, others I write from events that have happened with others who have posted about their gains or misfortunes.

The only way you will get anything out of this is by reading it in full and asking questions if needed. The suspension forum, as well as ALL of SS.net has MANY people who help out with forums and individuals needing help. One thing to realize though is learning from others mistakes. If not, the saying of a hard head makes a soft @!#$ can and usually does hold true.

To start of, the suspension is the main thing that SUSPENDS your car in the air with the base being the wheels and tires. Those are the 4 points that touch ground. Suspension arms, struts, springs, shocks, and twist beam are all components in helping keep the car up off the ground/road and also controlled so the inside components of the car (aka you, the passenger(s) are not shaken nutty.

Through this post I will cover a few points that are now frequently asked and give explanations and or proof in form of logic, or quotes.

Starting off, WHAT SHOULD I CHOOSE? WHATS THE BEST…?

Firstly, BEST? Drop that word from you vocab. Seriously…Obviously what’s “best” for you isn’t gonna be best for marky mark, and what’s best for you two isn’t gonna be what’s best for jimmy jam. There isn’t a “best” you can just look up on a chart. There are plenty of parts that are good for a certain person or application that aren’t for another.
SO……What should each person choose? What is better? These are two commonly asked questions by newbies and people who aren’t new overall, but new to suspension. What SHOULD you choose? Well look at what you want to use your suspension for and what you plan to accomplish. Ask yourself these questions:

How low do you want to be from stock? The lower you go the harsher the ride. And the greater the chance you will damage the under side of your car on a bad road or parking lot entrence.

How soft or stiff do you want ride quality?

How much do you want to pay?

How many times do you want to half-@!#$ this before its done right?

How quick do you want to be able to adjust it? Or are you into adjusting at all?

How critical are you when it comes to being COMPLETELY EVEN?

How are the roads in your area?

Those are just a few questions to ask yourself. Those are to help YOU decide what YOU need and or WANT.

When you get that figured out, here is an overview of the choices for suspension. In all choices however, there are CHEAP and QUALITY choices. This will obviously help you in figuring out what way you wanna go. But do realize that cheap isn’t always good and neither is expensive. Going cheap will obviously get you a cheap product. Cheap products I tend to view as this: “if this was underwear, would you want it housing family jewels?” you normally don’t put cheap stuff for protection. Cause in essence, your suspension can and will be part of the equation of keeping you safe on the road or having your car, body, and hopefully not…other passengers from being harmed, if there ever comes a time when you need to brake hard, swerve, or use some other evasive driving moves in an emergency.

*** Don’t be one of the ones, I don’t have enough money. Instead of giving the BS I’m poor story, do realize its not gonna hurt you to save up for a part you need. Everyone here is not a millionaire. If need be get a job, get two, or simply save up. There are people here with a house, 2 kids and working minimum wage and can save up. If saving up is a problem for you, then its time to start growing up. All the people who don’t wannt spend that much money, but have their car loaded with audio equipment, get real. Quality costs, and you get what you pay for. No bullsh*t. no excuses***

In a quick overview, the main choices for suspension are:

Stock: Obviously, the smoothest but prob the most sloppiest, when it comes to crisp handling. Also the cheapest. Talking about the base cars here.

Stock SS: This is a good set up and a good upgrade for the base cars. It will give you a good ride and still have handling that is beter then most of the cars in its class. And will beat most moded lower class cars as well.

Lowering springs: These NOW come in linear and progressive springs. They are not adjustable, so what you put on is really what you get unless you wanna pay money to buy more stuff to try and adjust em. This, in an aftermarket sense, is the “low-cost” way of lowering a car. All it really involves is a change of springs, but strut change is also HIGHLY recommended. But sins there are no struts and shocks out for this car yet I would keep the drop to less then 1.5" front and back for both the SS and the base.

Coilovers: Coilovers usually always came in Linear spring rates. But they may come in a progressive rate to. You will need to ask when ordering them. But these are usually higher priced coilovers. AKA not on EBAY.
Coilovers are GREAT for adjusting as that is their main advantage. You can change the spring rate as well as the spring length, the height at which the car sits and if you are critical in all sides being even you can adjust these to the nearest micrometer if you have the patience. These are especially good in racing and in shows where height may need to be adjusted low for stability, or to wow the crowd and judges, but it allows you to leave the track or show at the height you came in with if it was higher. VERY versatile. Downside, more expensive, and there are so many cheap knock offs that come without essential parts for the car. These are the kits that are made for other cars, but can be adapted, so they change the part numbers, most put them on ebay, and they are usually less than 200$…but take a moment and think. A quality set of springs are around 200$ why are coilovers, with more parts less than a decent set of springs?
If you cant conduce an answer from that, sit down, drink some milk, and have a nap, cause you are really muffed up!J

***Linear means the spring throughout the WHOLE coil is the same spring rate. So if the spring was 350lb/in, that means the spring would need 350 lbs to compress it EACH inch. Now, some coilovers, mostly FULL coilovers, not sleeve style kits are coming with progressive spring rates. Progressive springs DO NOT have a set spring rate as linear. The reason why is because each section of the spring has a spring rate that is different from the next. So the top half of the spring may be 115lb/in, then gradually reach 320lb.in by the other side. The spring rate of that spring literally would be everything between those two rates, but then it would be pointless cause you would have to list every rate and some springs do jumps like 115, 225, 320. point being there is not industry standard to measure it, or no real way to measure it at all. Some people may think that you can measure the ends and come up with a range to list., but it simply cant be done like that.
What if the first coil is somewhere in the ranges of 115 starting and slightly in the 200’s after the first inch. Then for that first inch, its not really 115 nor 200 is more of an average of the two… too technical and will never be solved, but if someone is bored, they are welcome to try.

Air/Hydraulics: although this is a route lesser traveled, its definitely picking up as of late. To be honest I never saw the point of this but the more I read on it the cooler it seams to get.
You basically get the same effect as coilovers, a lot of adjustability, and all at the flick of a switch. Some of the myths of air ride is that they are accident prone. You have more parts and you are dealing with hoses, but once again, the statement holds true about the quality of the products. Make sure you buy something decent, not some schmuck on ebay who answers you question of “does this come with everything I need?” with a reply of “yeah I think so, so and so told me.”
The only negative I really see with air rides, is that most tracks, US wise, pretty much the majority, will not let a car with them race. Sure many have snuck in, but during tech, if they see it, most will not let you race. Track safety hazard from debris hitting the bags or lines are the common reasons. Check with local tracks before you go to get rules and regulations.

STRUTS
Now that you have a base on what choices to choose from, start thinking and prepping to spend extra money on some struts if need be applies. They will be out at some point.
Air struts are specially made with either bags on them or an air cylinder inside. So you don’t need lowering struts for those. However, on springs and coilovers, struts should be your first buy. But untill some one makse us some you will just have to wait like every one els. Sucks I know.
Once you have struts, you can put almost anything on them and not have to worry about the struts failing. That is as long as you buy struts the will work for what you want. And set them correctly if they are adjustable.
Once the struts fail, so has the stability of your car. The struts are the mainstay of mechanical suspension. They control the motion of the spring. The spring is there to help the car stay suspended, while the strut is to control the smoothness. Remember the POGO stick from childhood. It was fun cause you kept bouncing, but imagine how hard it would have been if pressurized oil was inside and controlled motion. It would have sucked then, but now with a car its what you look for. CONTROL…

Strut choices for the cobalt are well.... there are non out yet. Sorry.
And since there isn’t that big of a market, they will be high in price when we do finaly get them. With the Delta-body platform, you might as well get used to it.


Generally a strut should last well up to 5 years or more if not abused. If it does blow before time, then that’s more money to spend on new struts, alignment (you will need an alignment after every major suspension component change),

A list of all the OEM style replacement are:

-GM stock. (Base)
-GM stock or upgraded suspension packages. (SS)
-Nothing els is out yet. But Ill update this as they come out.

LOWERING STRUTS

These struts are valved stiffer to handle stiffer springs and increase the stability of a lowered car. They aren’t cheap.
ANY strut when its new and freshly installed will work good for a while. Hell a 10 matchsticks can hold up 50-100lbs, but after a while they fatigue and wear. Obviously, 10 sticks of the same size in metal would be better, or even of a better wood, would be better, but once again the fact prevails, quality you pay more for. You get what you pay for in this area. You get cheap struts, the don’t last as long. Some have been for 2 weeks, some 2 years. But stock struts are going to fail sooner or later when lowered.
Learn from others experience and losses, get the right thing upfront and don’t wast time changing cheaper struts, and spending more money replacing things and more alignments. Although some will not listen.


Lowering Struts are as listed:

-Nothing! Sorry. But Ill update this to as they come out.

***SLAMMED CARS with struts. Most companies…EVEN KONI will not warranty a strut if you ABUSE it. Riding around on a strut with the car slammed is abuse. Your car is a 2850+ lb vehicle. The equivalent of that would closely, be related to a large person on your back and you have to walk around all day in a squatted position. Your legs wouldn’t like it and neither does your struts. They have ways of testing to find out if you have done this or not. Simply put, you know how you can tell which part of a metal bar as been used by where the wear marks are concentrated. Well they can do the same with your strut shaft…***

Now hopefully we have struts down. Now since you should have by this time made the decision on your own from reading above what you want to put on the struts/shocks….springs or coilovers kits. Generally speaking, “how low should I lower my car” are to be decided by YOU not us… YOU. If you have a body kit, you need to go outside, measure how much clearance you have and how much you can get rid of safely. This can be done by anyone on any car. Find the lowest point on your car and then simply measure from the bottom of it to the ground. Lets say you get 5 inches, and you want to take off 2 inches, then look at the chart below and make the decision.


SPRINGS
If you choose springs here are your choices:

Spring Choices


1- Eibach Pro kit (1.6"F - 1.8"R) Base drop non SS. This should not drop the front on the SS S/C and drop the rear about .3". I dont know aobut the SS 2.4L.


2- Eibach Sportline (2'F - 2.5'R) Base drop non SS.


3-Progress. (2"F - 1.8"R) Base non SS.


4-Superior Sport Chassis (SSC) (1.5" F - 1.3" R) drop for Cobalt (Model unknown)


5-H&R. (1.6" F & 1.75" R) This is for the Cobalt SS.


6- Tenzo-R * STANDARD SUSPENSION: 2.0" Front Drop and 2.5." Rear Drop.
* SUPERCHARGED SS COUPE: 1.0" Front Drop and 1.3." Rear Drop.


I know there are more springs out there and if you post a link I will add them to the list but this is what I was ablt to find in a short time.

Basically here quality will pretty much show in price. The smaller drops will obviously cost less, only a little is changed from stock. So quality shouldn’t really be an issue there. But once you pass the 1.5 mark on a base car, when you hear someone’s springs like Intrax for example which are rated for 1.7, they say they are at a 2-inch drop or 2 and a quarter, that means the spring has SAGGED. Like a woman’s mammaries, we all should know sagging is NOT GOOD. Sure some people may still like the ride that’s their preference. Getting used to something isn’t always the best thing. People do it, but so do inmates when they become bubba’s b****. Eibach, H&R, B-G are among the top springs, with goldline in there as well. These are the springs that get low past 1.5…
Usually, even though those give a decent ride, people prefer stiffer springs, and most times lower, for increased handling and stability, but do keep in mind. There is more to the setup THAN JUST spring choice. It is possible to have a baddazz-handling car with a soft suspension and proper bracing and the correct anti-roll bars (sway bars). I will cover that a bit more later on.

Big Notice…springs and coilovers on ebay are cheap for a reason. As you see most quality springs are 150$-220$+, when you see springs on ebay being sold for 60$ there is a reason. I seriously hope logic kicks in for you.
For thous of you that are still not sure what not to buy heres a pic of some cheap ebay crap for you.



COILOVERS
Now on to coilovers, this section will be relatively short as I have already covered this.
They will all come with srtuts / shocks and are for the most part fully adjustable. Some more then others so do some checking befor buying.

Coil-Over Choices

1- RK Sport Coilover Kit
2- KW Suspension Variant 1 Coilovers


3- KW Suspension Variant 2 Coilovers


I know there are more but agen limited time here. Post a link and Ill add them to the list.


Lastly we get to Air ride. Its way more expensive than any full coilover kit, usually by 300 dollars. The avg kit runs about 1500 dollars for starters…the avg full coilover is around 1200$ but while I’ll spend 20 minutes lowering or raising my car, most air kits will do that in 2 seconds. That’s the advantage. Quick raising or lowering. The weight isn’t too much heavier than most regular suspension setups. Granted you will use up trunk or backseat space with the equipment needed. Air ride is def something you should look into for sure IF you want to ride around slammed Reason being is that they are designed to ride low and be in that position…I mean, besides farting, when was the last time you hurt air? Air rides have a high level of instant adjustability and when don’t right can last a long time. But the same as the other two options…this one still lives by the same rule of thumb. You buy cheap parts, you get cheap results.

Now there are still more parts to your suspension.

Antiroll bars are a big part.
These help keep the car level in a corner and that will alow you to make the most of the traction each tire has.
They are used to tune your suspension and should be one of your last upgrades.
There are a few out as of now and a few more coming.
Now when you decide to get a rear bar for your SS or base remeber that this will make the rear of the car a it more lose then it was stock and this can be a problem if you dont know what your doing at high speeds so be carefull! A base should not use a rear bar without a front bar ever!!!!
Base cars will most likely want to get a full kit with front and rear bars.
SS cars will need only a rear bar as the replacments are the same size as your stock front bar at this time.

Here is whats out right now.

1- Suspension Techniques Front and Rear Swaybar Kit. (2mm F - 19mm R) Thisi is more for the base cars as the SS stock front is 22mm.


2- Progress Rear Anti Sway Bar. (22mm) This is more for the SS cars and should not be put on the base unless the front has been upgraded to atleast a 22mm bar as well.

3-Eibach Front and rear bar. Sizes unknown. Not do out till late december 06.


I know there are more but agen time. Post and Ill add it.

Now we come to strut bars.
You can only have a front strut bar as this car dosnt have rear struts.
The strut bar will tighten the front of the car and make it more likely to understeer. This is good if you have added a rear anit sway bar and are having a problem with the car being to tail happy.
This will also help with auto-X. Most people do this mod and for good reason.

There are several bars out and more to come Im sure.

Bars out are.

1- DC sports.

2- XTC Strut Brace
3- MRZ Performance Strut Brace
4- JBP Strut Brace
5- Torque Forward Strut Brace

And yes there are more. POST!

Next is a rear tie bar.

Now this connects the left and right sides of the rear suspension to help prevent toe and camber changes under hard cornering. Some place refer to this a rear strut bar. Thats wrong but what ever. This will make the rear of your car tighter and more likely to come out in a hard turn. (Orver steer). This is a good mod for auto-X as well and will complament a strut bar nicely.

Places that make them are.

1-Bwoody performance.

And yes others. Post it.



Now last thing is bushings.
As of not the only this out is CAB's (Control arm bushings)
These will help to preven wheel hop and will also help in cornering.
They will prevent toe changes under hard acceleration and cornering and that will alow for beter traction.

Places making them.

1- J-body performance.

Although others sell them as well.

Well that about covers it.
If you have any thing to add just post it up and ill look at it.

Enjoy!



This part is a cut and paste:

Here is some more fundamentals on Springs.
Enjoy.
Understanding Coil Springs
Of all the parts on a race car, springs probably have the most influence on handling. Understanding springs can help you to better tune and trouble shoot your car.


What is spring rate?
Dynamics of coil springs.
What is spring stress?
Stress consideration in spring design.
What if a spring sets?
Monitoring your springs.
What is coil bind?
Why springs bow.
Spring checkers.






What is spring rate?


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Spring rate refers to the amount of weight needed to compress a spring an inch (Example:500# per inch) To understand and properly check a spring for rate you need to know the factors that determine the rate of the spring. Fortunately, there are only three things that affect spring rate, so there's not that much to remember!





1. Wire diameter. This affects rate since greater diameter wire is stronger than lesser diameter wire. So, when wire diameter is increased, spring rate increases.
2. Mean diameter of spring. Mean diameter is the overall outside diameter of the spring less one wire diameter. When mean diameter increases, the spring rate decreases.
3. Active coils. Determination of the number of active coils varies according to spring design. Count the total coils minus two for springs with both ends closed (includes all AFCOILS). Count the total coils minus one for springs with one end closed and one end open. As the number of active coils increases, the spring rate decreases.




If a spring's rate is linear (most racing springs have linear rates) its rate is not affected by the load put onto the spring. For example, a linear rate spring rated at 500#/inch will compress 1" when a 500# weight is placed onto the spring. If another 500 pound weight is put onto the spring the spring will compress another inch. At this point the load on the spring has increased to 1000 pounds. The rate of the spring, however, remains constant at 500#/inch.

If the load put onto a spring increases the rate of the spring, the spring is said to have a progressive rate. Progressive rate springs are sometimes used on torque arms to absorb engine torque. Keep in mind that the load (or preload) put onto a progressive rate spring can greatly increase the rate of the spring.

Typically, progressive rate springs are made by varying the spacing between the springs' active coils. During compression the close coils bottom out and deaden. This reduces the amount of active coils and spring rate increases as a result.

Springs that are designed to include coils of different diameter or are wound using a tapered wire will also produce a progressive rate.

Most coil springs are actually progressive to some degree -- as we will learn later!






Dynamics of coil springs


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There are basically three different spring designs presently used in race cars. They are:

TYPE 1. Closed and ground on both ends (Coil-overs and rear conventional springs are this type).
TYPE 2. Closed both ends but ground one end only (Conventional front springs are normally this type).
TYPE 3. Closed and ground on one end and open on the other end (Similar to a conventional spring that has been cut).




The 3 springs types are used in different situations and provide different effects to rate. Since the designs are so varied, it only follows that the dynamics of each design are also varied (more later). You must remember, however, the only factors that affect spring rate are wire diameter, mean diameter, number of active coils.

How spring rates change dynamically


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Keep in mind that as a coil spring compresses, the inactive (dead) end coils gradually contact adjacent, active coils. The contact causes the active coils to deaden which increases the rate of the spring. The rate creep that results usually stops after the first inch of spring travel and does not appear again until spring travel approaches coil bind. Generally speaking, this type of rate creep is of little consequence with springs softer than approximately 500#/inch. When you use springs stiffer than 500#/inch rate creep becomes more pronounced.

It is important for you to realize that springs will pick up rate during compression. Consequently, the rate marked on a spring can differ from the rate as seen by the chassis. This is especially true whenever a spring manufacturer rates springs based on the first inch of compression.

Example: A racer replaced a 720# coil-over spring with a 750# Afcoil. The racer believed he had stiffened his right front spring, however, the chassis behaved as though he had gone to a softer spring. Upon rating both springs, he found that the 720# spring was rated for its first inch of travel (720# in.) and produced a much higher (780# in.) rate for its second inch where it actually operated on the race car. Because Afcoils are designed to give their nominal rate closest to their actual working range of travel (this particular 750 spring rated 735# in. for its first inch of travel and 755# in. for its second inch), this racer actually softened up his race car even though the spring rate markings indicated the opposite! Rate creep can become even more complex and more difficult to monitor for racers using conventional type front coil springs designed with an open end coil(type 3). The lower control arms used with conventional springs typically incorporate a stepped helix spring seat built to an SAE specification (.720" of step). The helix seat was designed into lower control arms to insure consistent installation of the spring. Keep in mind that any rotation of the spring affects the actual installed rate of the spring.

Unless racing springs used for this type of application are designed with one end coil that closely matches the lower arm helix spring seat, a serious amount of rate creep can result. To minimize this type of rate creep, a conventional front spring should be wound with its bottom end closed so that it sits squarely in the helix seat. No active coil should touch the seat (just like the original production spring for which the control arm was designed -Type 2 spring).

When built in this manner, a coil springÂs only contact with the lower control arm is through an inactive (dead) coil (just like the spring's contact with the weight jack). Consequently, as the spring compresses, the number of active coils in the spring is not affected by the lower control arm. Therefore the spring's rate remains constant throughout normal suspension travel. Some rate creep still occurs due to contact between the dead end coils and the adjacent active coils as was explained earlier, but the amount of rate creep is miniscule compared to the rate creep produced by an open end coil spring. All AFCOILS, designed for use with stock lower control arms, are built in this manner.

If a spring has an open end coil(type #3), the open end coil is active but gradually deadens as the lower control arm moves against the spring. A considerable increase in spring rate occurs until the open end coil is completely seated in the helix.

For example, during a test a 1500# open end coil spring gained 464 lbs. of rate after 2 inches of spring travel. By comparison, a 1300# Afcoil (closed end coil spring) gained only 48 lbs. of rate after the same travel.

Further testing of a series of open end coil springs produced rate creep so inconsistent that at some points of spring travel the springs did not remain in the same rate order of softest to stiffest! It would be very difficult to make predictable handling adjustments using springs that exhibit such inconsistencies!

Keep in mind that any load change to an open end coil spring (via static weight, wedge, chassis roll, bumps, etc.) usually causes the spring's rate to change and, consequently, handling to change. If you are using open end coil springs you should chart their rates from static loaded height to fully loaded height weight(in one inch increments). You should compare this information before making spring changes. By now you should realize the importance of using springs that are designed to keep rate creep to a minimum.

What is spring stress?


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As was pointed out earlier, the rate of a spring is determined by its diameter, the number of its active coils, and the diameter of its wire. Since most racing springs are built to a fixed diameter, a spring designer must decide on the diameter of wire and the correct number of active coils needed to produce the desired rate.

If the designer chooses a smaller than normal diameter of wire (which tends to soften rate), he will have to compensate by using fewer active coils (which tends to stiffen rate) to achieve the desired rate. There are two possible reasons for a spring designer to use a smaller than normal wire diameter for a specific rate spring:

1. The ideal diameter wire may not be made and using the next larger wire (which requires more active coils) would produce a spring with insufficient spacing between its coils. This could cause the spring to bind during normal operation.
2. Cost could be the prime consideration and by using a smaller diameter wire and fewer coils (shortening the length of wire used) material cost is reduced. Unfortunately, many racing springs are built this way and these springs can cause a multitude of problems for the chassis tuner that we will cover.



Many racers mistakenly believe extra spacing between the coils of a spring indicates a preferable spring. While a spring must have sufficient stroke capacity it also must have sufficient material to absorb the load put onto it. If the spring's material is not sufficient for the load put onto the spring, the material will become over-stressed and the spring will take a set (lose height). Handling, of course, is affected and the reason is not always apparent to the racer unless he pays close attention to his springs.

Example: A typical asphalt late model set-up calls for a tremendous amount of load on the left rear spring (upwards to 600 pounds more weight than on the right rear spring). When the chassis sees normal spring travel, the cumulative load on the left rear spring produces a tremendous amount of stress in the spring. If the spring does not have sufficient material to handle the stress (as many don't), it will take a set (as many do) and the car will lose crossweight and tend to become loose off the corner. Excessive spacing between the coils of a spring is usually an indicator of a potential problem with spring stress.

Stress consideration in spring design


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Many times, because of the long stroke requirements for certain rates of racing springs, material strength must be sacrificed to achieve significant stroke. Couple this with the fact that the ideal wire diameter is not always made and you can see why some springs have a real potential to take a set. We have seen some brands of springs lose as much as 15/16" of free height during normal operation. To eliminate any set from occurring at the race track, it is good manufacturing policy to pre-set (press to solid height) all racing springs during their manufacture.

If done correctly, pre-setting will generally eliminate any potential for additional set, even when springs are designed with smaller than ideal wire. Shot-peening will further enhance a spring's durability. It should be pointed out that all Afcoils are pre-set and shot-peened during manufacture.

What if a spring "sets"?


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When a spring takes a set it will normally stabilize at its new height. The rate effectively remains the same since no appreciable changes have been made to any of the three factors that determine the spring's rate. Other than creating a need to readjust the chassis (to restore the original set-up and ride heights) the spring should provide satisfactory performance. It is not uncommon for even well designed and properly manufactured springs to settle up to 1% of their free height. It needs to be pointed out, however, that in cases where a poorly designed spring is subject to extreme over-stressing, the spring's height may not stabilize. The spring may continue to change height (both shortening and lengthening) as the spring is worked. As a result, the set-up on the race car changes every time the spring's height changes. This can cause major chassis tuning headaches!

Monitor your springs


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We recommend that you monitor the free heights of your springs on a regular basis. This is so important that some Indycar teams measure their springs' heights to the thousandth of an inch. Be sure to always measure height at the same point on the end coils(mark your springs to indicate the measuring point). You should suspect that a spring is setting whenever wheel weights continually change. Under no circumstances should springs be used that change more than 2% in height or do not stabilize in height. AFCOILS are guaranteed to maintain their free heights to within 2% forever!

At the least you should inspect all springs for free height changes after racing on a very rough track or if your race car was involved in a wreck. By now, you should realize there is much more chance for a spring to change its height than its rate. Consequently, you should spend your time monitoring your springs' free heights and not their rates!

What is coil bind?


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Coil bind occurs whenever a spring is compressed and one or more of the springs active coils contacts another coil. The rate of the spring increases whenever a coil binds since the bound coil or coils are no longer active(this changes one of the three rate-determining factors). Of course, handling is affected whenever a coil binds. If the spring is compressed to solid height (all coils touching) during suspension movement, the suspension will cease to work. You can, and should, check for evidence of coil bind by examining the finish between the active coils. If any coils have bound the finish between them will show contact marks that appear as though they were drawn with a lead pencil. Normally any spring that is binding should be replaced with a taller spring. Be aware, however, there are racing springs on the market that are built with wire that is heavier than what's needed. These springs will coil bind before others that are built with the proper size wire.

Under very extreme conditions, coil binding can cause a spring to unwind slightly. This can cause the mean diameter of the spring to increase and reduce rate of the spring. You should realize that the potential for coil bind is increased whenever short springs are used. Always match the spring to the job.

Why springs bow


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Springs that have lengths greater than 4 times their diameter will have a natural tendency to bow when loaded. Consequently, tall springs tend to bow more than short springs, and small diameter springs tend to bow more than large diameter springs. Generally, the more a spring is compressed the more it will tend to bow. Keep in mind the rate of a spring will increase if an active coil rubs another part of the race car. Here are some tips to minimize bowing:

• Use correctly fitting coil-over hardware or install weight jack assemblies so that the spring mounting surfaces are kept as parallel as possible during suspension travel..
• Use springs that do not lean excessively (when positioned on a flat surface). This indicates that the ends are ground parallel to each other. This reduces the tendency for a spring to bow. You should check both ends.
• If a coil-over spring is rubbing the shock, try reversing the spring so the bowed part of the spring is around the shaft where there's more clearance.
• Use coil-over springs that have straight sides rather than an hour glass shape. This maximizes the clearance between the shock and spring.
• Use springs that are wound straight. You can roll the spring on a flat surface to check for straightness.
• The new AFCO XCS coil-over springs were developed specifically to eliminate bowing and shock hardware interference problems.

There are special manufacturing techniques that help to keep bow to a minimum. AFCOILS are built for minimum bow under all racing conditions.

SPRING CHECKERS


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Unfortunately, we know of no reasonably priced spring checker that will accurately measure a spring for rate. We have tested most brands of checkers and cannot give recommendation to any. However, there are steps and procedures that can increase the reliability of the spring rate checkers commonly sold to racers. The accuracy of a spring checker should be monitored. This can be done through the use of a checking spring. A checking spring can be any spring that has been accurately rated at one inch (or smaller) increments up to a load close to the total capacity of the checker. It is important that the free length of the checking spring remain constant. The rates given by the checker can be compared to the known rates of the checking spring (at each increment of compression). Any rate discrepancies between the checker and the checking spring should be noted and taken into consideration when checking for rates of other springs.

AFCO can provide checking springs for this purpose. The repeatability of a spring rate checker should also be monitored. Simply put an old spring in your checker and preload it to at least 20 lbs. Then compress the spring and note gauge readings at 1" increments (or less) for the next three or four inches of spring travel. Tag the spring with this information and use it occasionally to check for repeatability. Make sure the free height of the spring remains constant. Do not use the spring if any change in free height occurs. A checking spring can also be used to check for repeatability. A rate checker should consistently repeat rates to within 2.5%.



Some final points on the use of spring rate checkers:


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• Preload Afcoil closed end conventional front springs 1/2". Coil-over and conventional rear springs should be preloaded 1".
• Always use similar preloads when checking different brands of springs. It's best to preload springs to a height equal to their loaded height (as installed in the race car) before checking for rate. This simulates what the race car sees for spring rate.
• Use a dial indicator to measure travel.
• Take dial indicator readings as close to the spring's center line as possible. Readings taken very far from the springs center may not allow for any rocking of the spring seat which distorts the actual amount of spring travel.
• Realize travel indicated stiff springs can flex the framework and fixtures of portable checkers. Consequently, the spring compresses less than its indicated & the rate shows softer than actual.
• The dial indicator should hold steady whenever rate readings are being taken. If the indicator moves, suspect the units framework is flexing or there is a problem with the units jacking device.
• Checkers equipped with load cells tend to be much more accurate than checkers equipped with hydraulic gauges.
• Avoid checkers that allow the spring seats to rock in any manner or amount.
• Always use the proper spring seats.
• When using a helix type spring seat make sure the spring is positioned against the stop in the helix.






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We have pointed out the more important features you need to consider when choosing and using coil springs. You should now have some basic understanding of the differences between springs and how those differences affect handling.

By knowing more about springs you will be able to confidently select springs that suit your application and expect that they will give consistent and trouble free performance.

Later.

VictoryRed06

Great Thread Man! Now we can hope that no one will ask anymore suspension questions...Requesting this to be a Sticky.

tonio5555

Sticky please.

laserblue2006

good job....helped me out A LOT


STICKY!!!!

HunterKiller89

iTrader: (1)

agreed...sticky it up!

Sicklyscott

iTrader: (1)

Definately should be a sticky.

Great job, that must have taken a real long time. I think someone should also take the time to do a driving dynamics post so people can know what to expect when lowering and making other modifications.

SS33

Sticky icky

Stilgar

Because the stock struts can't handle the load. There designed for stock ride height, when you lower it puts alot more stress on the struts. They are being compressed all the time so it wears them out a helluva lot quicker than stockers. There is also the chance of bottoming out with the stock struts when using lowering springs.

HunterKiller89

iTrader: (1)

okie...gotcha
aight..i think i know everything i need to on springs now....cept one last question...
are alignments required if you lower the car, or recommended....and what IS an alignment anyway? can i do it myself?

AZCobalt19

Thanks for the write up, I will definately refer to this when I plan on lowering my car.

Keep it up.

05BlackCobaltSS

Wow, that's one of the most extensive suspension write-up's i've seen. But most people don't know a whole lot about suspension and all the geometry, and how one little change can F up your whole ride. Good info, sticky worthy.

Badmunky

Thanks every one for the coments.


An alignment is needed when you lower a car as you change the suspension geometry and it can afect things like, toe angle and camber angle. This will need to be corrected.'

No you cant do it your seld unless you happen to have a $40,000+ doller alignment rack hanging around and know how to use it correctly. If so your my new best freind!

Improper alignment can couse, Poor handling, poor steering respons, poor braking, poor traction off the line, and exesive tire ware.

I always have one done after a suspension change.
Most places with check it for free and tell your out of spec and need to have it done.

This car only needs a front end alignment and that will usualy cost you about 50-70 bucks depending on where you live.






I guess this was not sticky worthy after all?

Later.

HunterKiller89

iTrader: (1)

bump until made sticky!
^^thnx for the info btw.

tonio5555

Sticky!!!!!!!!!!

jimbos'ss

iTrader: (2)

thats an awesome write up, thanks it gives me alot more ideas

laserblue2006

sticky!!!!!and badmunky for president!!!!!!!

DoubleClutchin_ION2

what does suspension mean?


lol jfwy

great write up

PatDamanCobalt

Add Tenzo's to the list of springs. And sticky ftw

patathSS

Has anyone PMed a mod about making it a stick????? If you all do that I bet they'll sticky it.

NJHK

Props to da Monkey. Glad you actually wrote this up instead of copying and pasting.

Badmunky

Thanks man.

I based this on a post by a member of J-body.org.

I did copy and past part of it. But most of it is me.

Ill do more writeups like this on other things such as suspension geometry and driving dynamics. As well as braking basics and many others that hav to do with the suspension and braking of the cars.

This is the area of the car that I know the most about.
On one of the other forums that I visit and moderate Im known as "The suspension God" LOL

Every one there has asked me for help at some point or another.

Im surprised that this is not a sticky yet. After all the members that asked for it an all.

I dont know who to contact to have it made a sticky my self. Any one els know?

Later

DC52NV

stuck. very good info here. thank you.

superSS/SC

PMed a mod for you guys, should be stuck now.

Edit: it has been stuck thanks DC52NV

DC52NV

np. thanks for letting me know. i read the title to this thread and was about to click on it but something came up and had to leave and forgot all about it. if any members see a thread that has some good info and think it should be stickied please pm a mod or use the report a thread button and say that you think it should be stickied. thank you.

rick1217

good write up!!