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Discussion Starter #1 (Edited)
SUSPENSION FAQ
i've decided to write a thread with extensive information/facts/and know-how about suspension.
first, we'll talk about-
spring rates-
defintion-
Spring rate : Usually expressed in lbs/in, it’s the force required to compress a linear spring one inch. Linear springs have a constant spring rate. Progressive springs have progressive spring rate that rise has the spring load increase.

lets use Megan Racing's "coil-over system" ( http://www.optionimports.com/hoci88.html )for an example-
the spring rates for the 1988-2000 civic/crx/delsol are the following-

400 in the front
350 in the rear

this means that the front springs will compress exactly 1 inch under a load of 400lbs, and the rear will compress 1 inch under a load of 350lbs.

basically, the higher the spring rate, the "stiffer" the spring will be, and also, the higher the spring rate, takes more wieght to compress than a lower spring rate.

here are some good definitions of spring rate that i found-
-the amount of force necessary to compress the spring, usually measured in one inch increments. A straight rate spring will take the same amount of force for the entire travel of the spring. A 500 lb rated spring will take 500 lbs of force to compress it one inch, another 500 lbs (total 1000) to compress it the second inch, and so on until the end of the spring travel. Now a progressive rate spring changes the force requirement as the spring is compressed.
-The amount of force needed to compress a spring. Typically measured in pounds/inch, or kilograms/centimeter.

also, when a spring/coil is compressed as far as it will go (the coils are touching one-another) it is called "coil bind length", and the spring rate is then infinite.

some more useful terms/definitons-

-Unsprung weight: Weight of the part of the car that is not supported by the suspension. It’s made of the weight of the tire, the wheel hub, the brake and half the weight of the axle and suspension links.

-Sprung weight: Weight of the car that loads the suspension. Equal to the overall weight minus the unsprung weight.

-Corner weight: It’s the weight of the car applied to ground through the tire. It’s made of the sprung weight plus the unsprung weight.

next, oversteer and understeer-

OVERSTEER-(or "loose")

Oversteer is when the car's rear tires lose grip in a turn while the front tires are still gripping. If the rear end starts to slide out from under you in a turn, that is oversteer. oversteer can be mellowed out by useing a rear sway bar, i like the selections from "the progress group" and "comptech" because the have the rear sub-frame reinforcement built in, which helps sturdy the sway bar mounting points and also prevents tearing of the subframe.

here are some ways to prevent/decrease oversteer-(increase understeer)
*increase front tire pressure
*decrease rear tire pressure
*smaller front tire section
*larger rear tire section
*more positive front wheel camber
*more negative rear wheel camber
*more front wheel toe in
*more rear wheel toe out
*more negative front wheel caster
*stiffer front springs
*softer rear springs
*stiffer (heavier) front sway bar
*softer (lighter) rear sway bar
*more forward weight distribution

UNDERSTEER-(or "tight")

Occurs when the wheels are turned, and the car does not turn at the same rate. Causes the front of the car to take a wider apex than the driver's steering lock requires. Also called push, or tight in the US. Can be corrected by adding more front downforce, sofening springs and rollbar, or reducing front tyre pressure. Extreme conditions cause a car to go straight on instead of turning for a corner.
A car is “understeering” when the rear tires have more traction than the front tires – the front end slides toward the outside of the turn instead of turning into the corner.

to decrease understeer, do the opposite of everything on the above list in blue.

NEXT-
camber/toe

camber-
Camber addresses the angle at which a tire makes contact with the track surface. "Positive camber" indicates the angle of the tire is tilted away from the vehicle's centerline while "negative camber" indicates the tire is tilted toward the centerline. A typical oval track setup would have positive camber in the left front and negative camber in the right front to help the vehicle make left-hand turns.
in english, lol-Camber refers to the angle of the wheels. Negative camber means the tops of the tires are closer together than the bottom; positive camber is the opposite.

toe-
The tire alignment which sets the tire to run evenly with the car. If a tire was “toed out” it would wear off the inside portion of the tire tread surface where it touches the ground. If a tire was “toed in” it would wear the outside area of the tire tread surface. A tire must me “in toe” to wear evenly and face the front direction evenly.
In order to provide stable tracking, all four tires are usually pointed slightly inwards if viewed from overhead. More toe-in provides more stability but increased tire drag. On high-speed oval tracks, these toe settings are even more crucial. Toe-out may be used in certain types of cars and situations, but toe-in is more common.

Cont'd............
 

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Discussion Starter #2 (Edited)
cont'd-
suspension parts-

sway bars-
these steady the chassis against front end roll and sway on turns. Stabilizers are designed to control this centrifugal tendency that forces a rising action on the side toward the inside of the turn. When the car turns and begins to lean over, the sway bar uses the upward force on the outer wheel to lift on the inner wheel, thus keeping the car more level.

shock/strut-

This part is also used within the chassis and is also known as a “shock absorber.” It consists of a rod or piston mounted in a gas filled cylinder. Racecars have specially built shocks that are used to absorb the energy created when the car goes over bumps or rough surfaces on the racetrack. There is a shock mounted with the spring near each wheel. The adjustable stiffness of the shocks also has a lot to do with the setup and handling of a racecar.
Unless a dampening structure is present, a car spring will extend and release the energy it absorbs from a bump at an uncontrolled rate. The spring will continue to bounce at its natural frequency until all of the energy originally put into it is used up. A suspension built on springs alone would make for an extremely bouncy ride and, depending on the terrain, an uncontrollable car.

Enter the shock absorber, or snubber, a device that controls unwanted spring motion through a process known as dampening. Shock absorbers slow down and reduce the magnitude of vibratory motions by turning the kinetic energy of suspension movement into heat energy that can be dissipated through hydraulic fluid. To understand how this works, it's best to look inside a shock absorber to see its structure and function.

A shock absorber is basically an oil pump placed between the frame of the car and the wheels. The upper mount of the shock connects to the frame (i.e., the sprung weight), while the lower mount connects to the axle, near the wheel (i.e., the unsprung weight). In a twin-tube design, one of the most common types of shock absorbers, the upper mount is connected to a piston rod, which in turn is connected to a piston, which in turn sits in a tube filled with hydraulic fluid. The inner tube is known as the pressure tube, and the outer tube is known as the reserve tube. The reserve tube stores excess hydraulic fluid.

When the car wheel encounters a bump in the road and causes the spring to coil and uncoil, the energy of the spring is transferred to the shock absorber through the upper mount, down through the piston rod and into the piston. Orifices perforate the piston and allow fluid to leak through as the piston moves up and down in the pressure tube. Because the orifices are relatively tiny, only a small amount of fluid, under great pressure, passes through. This slows down the piston, which in turn slows down the spring.

Shock absorbers work in two cycles -- the compression cycle and the extension cycle. The compression cycle occurs as the piston moves downward, compressing the hydraulic fluid in the chamber below the piston. The extension cycle occurs as the piston moves toward the top of the pressure tube, compressing the fluid in the chamber above the piston. A typical car or light truck will have more resistance during its extension cycle than its compression cycle. With that in mind, the compression cycle controls the motion of the vehicle's unsprung weight, while extension controls the heavier, sprung weight.

All modern shock absorbers are velocity-sensitive -- the faster the suspension moves, the more resistance the shock absorber provides. This enables shocks to adjust to road conditions and to control all of the unwanted motions that can occur in a moving vehicle, including bounce, sway, brake dive and acceleration squat.

suspension in general-

Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose - contributing to the car's handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.

Bushing-

a simple suspension bearing that accommodates limited rotary motion, typically made of two coaxial steel tubes bonded to a sleeve of rubber between them. The compliance of the bushing in different directions has a great effect on ride harshness and handling.

the bushing can be stiffer or softer. A stiffer bushing provides a more stable ride and prevents wobbling at higher speeds where a softer bushing allows for a softer ride with the ability to carve turns more easily.----Plain bearings are also referred to as bushings.

Springs-

Today's springing systems are based on one of four basic designs:


Coil springs - This is the most common type of spring and is, in essence, a heavy-duty torsion bar coiled around an axis. Coil springs compress and expand to absorb the motion of the wheels.


Leaf springs - This type of spring consists of several layers of metal (called "leaves") bound together to act as a single unit. Leaf springs were first used on horse-drawn carriages and were found on most American automobiles until 1985. They are still used today on most trucks and heavy-duty vehicles.


Torsion bars - Torsion bars use the twisting properties of a steel bar to provide coil-spring-like performance. This is how they work: One end of a bar is anchored to the vehicle frame. The other end is attached to a wishbone, which acts like a lever that moves perpendicular to the torsion bar. When the wheel hits a bump, vertical motion is transferred to the wishbone and then, through the levering action, to the torsion bar. The torsion bar then twists along its axis to provide the spring force. European carmakers used this system extensively, as did Packard and Chrysler in the United States, through the 1950s and 1960s.


Air springs - Air springs, which consist of a cylindrical chamber of air positioned between the wheel and the car's body, use the compressive qualities of air to absorb wheel vibrations. The concept is actually more than a century old and could be found on horse-drawn buggies. Air springs from this era were made from air-filled, leather diaphragms, much like a bellows; they were replaced with molded-rubber air springs in the 1930s.

independent suspension-
If both the front and back suspensions are independent, then all of the wheels are mounted and sprung individually, resulting in what car advertisements tout as "four-wheel independent suspension." Any suspension that can be used on the front of the car can be used on the rear, and versions of the front independent systems described in the previous section can be found on the rear axles.

cont'd............
 

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Discussion Starter #3 (Edited)
cont'd-
EG6-Jarhead said:
i like the selections from "the progress group" and "comptech" because the have the rear sub-frame reinforcement built in, which helps sturdy the sway bar mounting points and also prevents tearing of the subframe.
im gonna quote myself here because i wanted to clarify the "subframe-reinforcment".
progress group sway bar w/ sub-frame reinforcement-

comptech sway bar w/ sub-frame reinforcement-

you can get the progress group sway bar and sub-frame reinforcement for around $200.00 shipped, the comptech is more expensive...but both perform the same function very well.

or you could spend $179.99 plus shipping for just the sub-frame reinforcment, like this one-


*i just wanted to emphasize that it would be cheaper to purchase the progress group's, or comptech's rear sway bar....rather than spending the money to get the sway bar, and then buying a sub-frame reinforcement separately.

wheel hop and how to eliminate it-
definition of wheel-hop...
An undesirable suspension characteristic in which a wheel (or several) moves up and down so violently that it actually leaves the ground. Wheel hop can be caused by many problems, including excessive unsprung weight, insufficient shock damping, or poor torsional axel control.
wheel hop sucks, it makes for horrible 60 foot times, and pretty much ruins ur launches.
if u have an 88-91 honda, replace the radious arm bushings or some energy-suspension bushings.
if u have a 92-2000, buy h-braces/after-market radious arms.
for 92-00, buy this to eliminate wheel hop-

here's the item description-

Preloads front suspension to completely eliminate wheel hop
Front wheel remain firmly planted to the pavement for maximum traction during launch and dramatically reduced 60-ft. times!

Ideal for drag, autocross and road racing. Features unibody cross-over anchor and adjustable-length lower control arm links. With left and right high-quality racing-grade threaded spherical rod ends. Steel. Include hardware, instructions.

LOWERING-
ok....everybody knows that lowering ur car looks awesome and can increase handling and steering response dramatically. So do it right the first time! dont lower ur car with just springs,do it right and buy a nice set of shocks/struts so u know ur spring/shock set-up will hold upto what u throw at it.
for springs i reccomend:
1. Ground control
2. H&R
3. Tein
4. eibach
for shocks/struts i reccomend:
1. KYB GR2's, or KYB adjustables
2. Tokico
3. Koni
4. Tein

personally what i would do before you decide to lower your car is catch rides with some of ur friends that are already lowered and then decide the pro's and con's of each set-up.

sources-
http://www.carsuspensionguide.com/
http://en.wikipedia.org/wiki/Main_Page

thats all for now, if you have somthing to add....DO IT!
thanks all.
:mikej: :TU:
 

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nice write up...helped me out some(if its correct which im gussing it is) rep for you
 

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FAMILY MEMBER #316
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you should get this stickied... like i have an obsession with electronics in a car; is your "thing" suspension?
 

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Discussion Starter #7
rattmann316 said:
you should get this stickied... like i have an obsession with electronics in a car; is your "thing" suspension?
actually im more of a motor head...but i figured i'd do u and me a favor and research the parts of suspension set-ups...i learned a lot from my suspension research, and i hope that everyone else does too. :TU:
 

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The Great Weldini
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very good write, i must say. i do want to add this. you stated that h-brace wikk help wheel hop. well since i've been a megan hands down follower, till today. i took off my h-brace off cause i snap it, i will be post a thread on it with pic it clearly snap clean in two place. and the other side started to snap off too. so down't get a h-brace i clearly snap it.
 

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Discussion Starter #13
remoer said:
very good write, i must say. i do want to add this. you stated that h-brace wikk help wheel hop. well since i've been a megan hands down follower, till today. i took off my h-brace off cause i snap it, i will be post a thread on it with pic it clearly snap clean in two place. and the other side started to snap off too. so down't get a h-brace i clearly snap it.
cool, thanks for the info, it always good to get advice from some1 thats actually had the product, :TU:
 

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The Great Weldini
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EG6-Jarhead said:
cool, thanks for the info, it always good to get advice from some1 thats actually had the product, :TU:
give me a bit i'll post up a thread on it.
here's what my h-brace looked like after a little tear and wear.

 

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x2,000 for a STICKY!

GREAT write-up! Great info!
 
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