performance Springs Valve Springs are manufactured to a strict quality standard to ensure that you get the best for your dollar. Valve Springs come to you already scragged to save you time (scragging is a process where the spring is compressed to solid before checking loads).
Springs are scragged individually to ensure each spring is too solid height before checking, unlike most that are scragged to a height somewhere close to solid. Valve Spring wire is also double eddy current tested to a depth of 40 microns and any wire detected with flaws is sprayed, the coiling machine picks this up and rejects these sections.
They are also rattle tested on a specially designed machine which we can put a cam lobe into and run a complete set up (lifter, spring, retainer, pushrod, rocker, and valve) and check for harmonics.