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 ACTIVE 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. This is best done with the height adjuster completely relaxed or removed from the coil entirely. Count only the coils that are not touching another or the end of the shock absorber. The top and bottom coils touching the spring seats re not counted.

Count the active 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 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 (.062") could result in as much as a 30 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 (.062") could result in as much as a 300 pound error.

ENTER YOUR MEASUREMENTS :  Determine your approximate coil spring rate. The more accurate your measurements are, the more accurate your result will be.