Effective, Real world, Race & Street Proven Parts & Accessories

Before you order your Cobra Valley R/T Suspension package, if you do not know your current spring rate and would like to compare what you have to what you may want to order, use the measurement guide below to submit your exact specs and Cobra Valley will evaluate and calculate these for you!

COUNT THE NUMBER OF FREE COILS:  First ensure the coil spring is unloaded and completely extended. The spring should be loose and wiggle or be able to be easily rotated on the shock by hand. Count only the coils that are not touching another or the end of the shock absorber. Count the free coils in a perfect vertical line from top to bottom. If you rotate the shock a coil at the top will become nearer to touching while the coil at the bottom will become further from touching. To the left is the same shock rotated 180 degrees to illustrate this result. Be very accurate in this count, one coil off could result in as much as a 100 pound error.

MEASURE THE FREE LENGTH OF SPRING:  With the coil uncompressed and "loose", measure the free length of the spring from top to bottom.

MEASURE THE OUTER SPRING DIAMETER:  Measure the outer diameter of the coil spring using a dial caliper. Be sure to keep the caliper perfectly 90 degrees to the coil so you are measuring directly across the coil, not at an up or downward angle. Be very accurate in this measurement, just 1/16" error could result in as much as a 300 pound error.

MEASURE THE WIRE DIAMETER:  Measure the outer diameter of the WIRE of the coil spring using a dial caliper. Be sure to keep the caliper perfectly in line with the coil so you are measuring directly across the coil wire, not at a side angle. Be very accurate in this measurement, just 1/16" error could result in as much as a 300 pound error.

FREE
COILS

WIRE
DIA

COIL
O.D.

COIL
LENGTH

FRONT

REAR

MODEL

CAR CHASSIS NUMBER

ENTER YOUR MEASAUREMENTS :  enter and submit your spring specifications where we will evaluate and determine your approximate coil spring rate

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