A New Era for GP Touring Car Racing! At the initial stage of suspension movement, a soft, supple spring is ideal. However, in high-speed corners, a soft spring may not provide enough support under heavy loads. On the other hand, a stiffer spring designed to handle these high loads can be too stiff during the initial stage of suspension movement. Finding the ideal spring for different circuits and track conditions has always been a challenge, often requiring considerable time and effort to achieve the right setup. Our new Progressive Springs solve this problem! By combining closely wound and widely spaced coils, these springs provide different levels of support throughout the suspension travel, delivering the ideal balance between initial softness and support under heavy loads. Developed by SMJ's spring specialist, Masayuki Miura, this versatile lineup offers options optimized for each racing category.