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HOW TO'S   WHAT IF'S
What you need to know to get the max from our products

Sway-A-Way has greatly expanded the Tech Room. Customers can find updated technical and application information here on our complete line of Sway-A-Way Suspension Components and accessories.

ON LINE CALCULATORS are available to calculate spring rates, wheel rates, dual spring rates, torsion bar rates and more for a variety of different suspension designs. The nature of suspension products lends them to many varied applications of one part number. Proper selection, use, installation, and maintenance may require prior suspension knowledge and familiarity with your particular performance requirements. Feel free to utilize the tools in this Tech Room and/or our experienced staff to assure the best selection and use of Sway-A-Way products.

Tool One: SUSPENSION WORKSHEET with  ON LINE CALCULATORS

Tool Two: INSTALL INSTRUCTIONS

Tool Three: DIAGRAMS

Tool Four: VW GUIDES

Tool Five: ARTICLES on Technical Topics
• Off-Road Race Shock Revalve How-To
• Axle Length Measurement Instructions

Suspension Worksheet

Unsprung Corner Weight is the part of the vehicle weight that moves with the wheel.  It is best to minimize unsprung corner weight.

• Unsprung weight is the weight of the wheel, hub, upright, brakes and plus about one half the weight of the shock/spring and A-arm/I-beam assembly. For most of the rear suspensions of trucks, the unsprung weight is the tires, wheels, brakes and the whole rear end and about half the weight of the shock/spring and trailing arm.

• To get this value from an existing vehicle: 
  Support the vehicle weight with a lift or a jack so that the vehicle is not suspended on the suspension system. 

• Remove shock, spring and swaybar (if any). 

• Make sure the vehicle is at ride height.

• Place the scales (weight scales) under each tire and record the value as Corner Unsprung Weight. 

Sprung Corner Weight is the part of the vehicle weight that is sitting on the suspension springs.  You can also estimate this as the total vehicle corner weight minus the unsprung corner weight.  Please note that the Sprung Weight is not the same as corner weight because the corner weight includes the Unsprung Corner weight.

• Weight the vehicle and record the corner weights.  Subtract the corner unsprung weight value from the corner weight value for each corner and record the result as sprung corner weight.

Wheel Rate is the effective spring rate at the wheel.  It is also the amount of weight (lbs) it takes to lower the vehicle one inch (per corner).  You can also see it as change in the load on wheel as the wheel travels vertically.
            In order to determine wheel rate, you must know the vehicles Sprung Weight, and the wheel travel.

• For example if your corner wheel rate is 200 lb/in then loading 200 lb weight on that corner will lower that corner one inch.  This value is very important since it tells how much the vehicle corner sprung weight will lower the vehicle with a given wheel rate, which in the end determines your ride height. 
  

Spring Rate is the change in spring load as the spring compresses/twists.  The spring rate is chosen to achieve the wheel rate desired. 

• Spring rate is equal to the wheel rate divided twice by the motion ratio. 

• Spring Rate can be calculated using the Tech Room Main Calculator.

• To get this value from an existing vehicle spring either test the spring with proper equipment or measure the physical dimensions of the coil spring and enter them to Tech Room Spring Rate Calculator.

Spring Preload is the distance the spring is compressed when the suspension is at full droop/extension.  For a coil-over set-up the spring preload would also be equal the distance the spring is compressed when the shock is at full extension.

Dual Rate Spring Set Up
Generally, off-road suspensions will use Dual Rate spring configurations. A Dual Rate configuration utilizes two springs: a Main Spring and a Tender spring.

The Main Spring is the spring that covers the shaft of the shock. The Main Spring should have a higher spring rate and it should be equal or longer in length than the Tender Spring. The rate of the Main Spring will be equal to the Secondary Rate.

The Tender spring is the spring that covers the threaded body of the shock. The Tender Spring should have a lower spring rate and it should be equal or shorter in length than the Main Spring.

A Dual Rate spring configuration will have a Primary Rate that is a combination of the Main Spring and Tender Spring.  When the Tender Spring coil binds or the slider hits the stopper, the Secondary Rate will take effect.

• You can use the Tech Room Calculators to calculate the primary and secondary rates of dual rate set ups.

Slider (also called floater) is a part that sits between the springs and guides the springs on the shock body.  It stops moving when it hits the slider stopper, which causes the secondary rate to take effect by stopping the tender spring movement.

Almost all of our products use lock ring type slider stoppers.  These lock rings are jammed against each other at the desired location.  In general the lock rings are located so that the secondary rate comes in to effect in the last 20% to 40% of compression travel.  This way the suspension will have a higher wheel rate for 20% to 40% of total travel before the shock bottoms out.

•  You can calculate the slider travel for a given shock travel to find out when the secondary rate will take effect.  Based on this information, you can place the lock rings at the proper location.