An industry leader since it was established in 1996, PSI (Performance Springs, Inc.) has worked continuously to expand their range of specialized valve spring applications. Currently offering springs for circle track, drag and road racing, PSI springs also feature heat-treating, nitriding and the new Max Life surface preparation process for various applications. Each and every PSI spring begins with wire that is made from the highest quality Chrome-Silicon alloys. Through the use of the latest developments in melt technology, composition control and casting practices, these alloys are held to the strictest cleanliness standards ever offered. As a result, the use of these super clean materials also insures the lowest inclusion content possible. Their superior technology does not stop with the wire. PSI uses state-of-the-art CNC equipment throughout the manufacturing process to ensure batch-to-batch consistency and valve springs that are held to the tightest tolerances in the industry. At PSI, all production processes are done in-house according to strict Quality Control procedures with each spring proudly made in the USA. All PSI springs are 100% load tested and set matched for the ultimate in customer convenience and satisfaction.