Is it normal for all springs to bow under load?

Some brands of springs "bow" excessively under load causing them to make contact with the shock body. This contact not only affects the car's corner weights but also puts additional heat into the shock through friction between the shock body and the coil. Some manufacturers have tried to put a band aid on this problem by using a plastic sleeve to stop the bowing from wearing the shock body. This may stop the shock body from wearing but anytime one of the coils rub the shock body / plastic sleeve the effective spring rate goes up considerably, and the car's handling changes. All Hypercoils are designed and manufactured to resist bowing under load.

Do you have URL's for regulating bodies for different types of racing?

Yes we do! Below is a set of links for every class of racing that has benefited from use of our race car coils, hydraulic perches and composite leaf springs.

Where can I get help with setting a chassis to obtain the best racing performance?

Most professional racers and race car builders have found that you can “fine tune” the suspension and set-up components and gain a competitive advantage. Since we offer a comprehensive range of suspension products, our customers ask us many questions concerning the best way to set up a chassis. For example, they ask what is the best way to size springs, calculate panhard/j-bar height, sway bar size, in order to optimize weight transfer to improve their car's balance during turns. Such knowledge allows accurate setup, improved handling consistency and most of all, lap times that stay fast and consistent throughout the race. With correct setup, the car's handling balance will stay more consistent through changing track conditions. We suggest the following three ways to gain accurate knowledge that applies to your particular race car: (1) Purchase software, (2) Attend a seminar or (3) Purchase educational publications.

(1) Purchase Software: Chassis R & D Software lets users examine alternatives & gives answers that are needed in order to make the correct decisions about chassis set up prior to a race. Such software removes trial & error.

(2) Attend a Seminar: Hyperco is familiar with two seminars, one on chassis design given by Claude Rouelle and another on tires & handling by Paul Haney. Such seminars cover topics like: dampers, the use of data acquisition, camber, caster and track variations, bump steer, roll centers movements, anti squat & anti dive, pro or anti Ackerman geometry, and the theory behind tire selection. Paul also offers a book on the subject of tire selection.

(3)Order Publications: Steve Smith Autosports has several publications on Chassis Design available for purchase on-line.

What are the most common Tech Tips for using Composite Leaf Springs?

Here is the list of the most common tips we have given our customers concerning the use of Composite Leaf Springs:

How do I install your leaf springs on a Camaro or Chrysler car?

               

How do you measure the composite leaf springs?

Is there a way to avoid having to unload suspension coils during transportation?

Whether or not it is necessary to unload the coils in the pit, or block the car while it is being transported depends upon the type of suspension coils you use. If you purchase high quality springs with the correct length, and are also designed for the rigors of professional racing conditions you should not need to jack up the car. You must also ensure that the spring is not being slammed or hammered coil bound. This could happen if the car becomes airborne, and bounces one corner or hits a curb.

High performance springs, such as those which we manufacture, will save you time and will not take set. In addition they will provide you a performance advantage during the race itself.

Do you have a list of useful equations for performing spring calculations?

Yes, we do! Below you will find various formulae that racers have used to evaluate performance of different configuration options.

Solid Height
Solid Height	= (Number of Coils – 0.25) x Wire Diameter
For example, for a spring with 14 coils and a wire diameter of 0.5”, the Solid Height would be calculated as follows:
Solid Height	= (14 – 0.25) x 0.5 = 6.875
Rate
Rate	= Load (lbs.) ÷ Spring Deflection (in.)
For example, if a spring deflects by 2.75” under a load of 300 lbs, the Rate would be calculated as follows:
Rate	= 300 ÷ 2.75 = 109
Deflection
Deflection	= Load (lbs) ÷ Rate
For example, a spring under a load of 300 lbs with a 109 Rate, the deflection would be calculated as follows:
Deflection	= 300 ÷ 109 = 2.75
Load
Load	= Deflection x Rate
For example, a spring with a 109 Rate and a 2.75” deflection, the load would be calculated as follows:
Deflection	= 2.75 ÷ 109 = 300
Combined Spring Rate This is used when two springs are stacked on top of each other. Combined Spring Rate = (Spring Rate 'A' x Spring rate 'B') ÷ (Spring Rate 'A'+Spring Rate 'B') For example if the rate for spring 'A' is 200 and the rate for spring 'B' is 500, the combined rate is calculated as follows: Combined Spring Rate = (200x500) ÷ (200+500) = 143

How often should the perch be rebuilt and what is the best way to perform the rebuild?

Time Between Rebuilds

Hydraulic perch is a precision product that is in constant motion while you are out on the track. While conditions of operation will vary the rebuild requirements, we recommend a maximum cycle time between rebuilds of 10-12 hours. Dirty environments and high loading will decrease the time allowable between rebuilds.

Required Tools

Regular flat blade screwdriver- used to pry the 2 halves apart (or use aluminum wedge)

Small Phillips screwdriver - for removal and insertion of the sealing screws

Dental pick, or a toothpick - for removal of the seals

Small, flat-bottomed pan, 1.5” deep - for refilling and bleeding the unit

Gap setting ring - used to set the proper gap between the two halves. Each model of perch requires it’s own special gap setting ring, and are available separate from the rebuild kits.

Consult us for the proper ring. 1 qt plastic bottle of oil with ¼” diameter tip - used to fill the assembly.

Rebuild Kits

Use only official Hyperco/ICP rebuild components!

Rebuild kits are available for each model. Please specify which model you have when ordering the kit. Use of other than Hyperco/ICP supplied components will result in the unit’s failure to operate correctly, or damage to the unit. The seals are Teflon coated for us on a custom basis – do not use standard o-rings! Failure to use seals with Teflon coating will result in the unit sticking and not functioning correctly.

Step 1

Remove the sealing screws and throw away – they need to be replaced with each rebuild.

Gently pry apart the two halves. Use caution – DO NOT SCRATCH THE WALL SURFACES!

Remove the seals using the pick. Again, use caution so as to not scratch or ding the surfaces.

Spray the surfaces clean of all residual oil, and inspect the surfaces for any wear marks or scratches.

Line type scratches indicate that dirt was trapped between the walls. Wide areas of scuffing indicate that the unit’s halves were not aligned correctly and rubbed against each other.

Step 2

Install the new seals. Inspect first to be sure that they do not have any molding parting line flashing, or nicks.

Coat the walls and the seals with the grease provided. A cotton swab is provided in the rebuild kit for your convenience. Use as little grease as possible – it only needs to coat the surface with a thin film. FAILURE TO COAT THE SURFACE WITH THE SPECIAL GREASE PROVIDED WILL RESULT IN THE UNIT NOT OPERATING CORRECTLY! This special grease is necessary to prevent the seals from sticking to the walls after being motionless for a while.

Step 3

Squeeze the 2 halves together, using the Gap Setting Ring to align the halves. Keep the halves as square as possible to each other while squeezing – allowing them to tilt while being pushed together will most likely push a section of one or both of the seals out of its groove and destroy the seal.

Step 4

Fill the unit by inverting the oil bottle and pushing the tip into one of the sealing screw recesses. Keep firm pressure on the piston with one hand to keep it seated against the Gap Setting Ring.

Squeeze the bottle to force fluid thru the perch until no more air bubbles appear. It is advisable to stop squeezing the bottle a few times to allow any bubbles trapped in an area of turbulence to dislodge themselves.

Install the screws. Again, keep a steady pressure with one hand against the piston to keep it firmly seated against the Gap Setting Ring. If you remove the pressure before both screws are fully seated, it is possible to suck air back into the fluid cavity. If that happens, you will have to bleed the unit again.

We recommend that a high-quality synthetic gear lube with a moly additive be used, or you may purchase it from us. Do not use brake fluid! The standard seals are not compatible with brake fluids – they will swell and seize up the unit.

Step 5

Remove the unit from the pan. Remove the gap setting ring and set the unit on its edge for a few minutes to allow any oil trapped between the two halves to drain out. Spray clean with brake clean or in a parts washer. Dry with a rag.

Work the unit with your fingers to make sure that it moves freely and that there are no leaks. If it doesn’t move freely, recheck the gap with the setting ring – if the gap is incorrect, reinstall the Gap Setting Ring, remove the screws while maintaining pressure on the perch and re-bleed.

Repeat the cleaning and draining process.

You will often see a light coat of fluid on the surface of the outer wall – this is normal.

Reinstall on the shock.

Download PDF Instructions