While the Mazda-powered Argo JM19s were busy carving a dynasty with their high-revving rotary shriek, another, more guttural beast was stalking the IMSA GTP Lights grid: the 1986 Argo JM19 Buick V6. This was the American-hearted alternative, a brutal counterpoint to its Japanese-powered sibling, showcasing the brilliant versatility of the Argo chassis.

Instead of the Wankel’s lightweight finesse, this JM19 was animated by the raw, torque-laden punch of a turbocharged Buick V6. This was a powerplant born from American ingenuity, a motor famous for its “big-power-in-a-small-package” philosophy. In the back of the lightweight Argo, this turbo V6 was an absolute monster, delivering a thumping, mid-range wallop of acceleration that demanded respect.

The sound alone set it apart. Where the Mazda screamed, the Buick roared—a deep, baritone thunder overlaid with the unmistakable whistle and whoosh of a high-capacity turbocharger. It represented a different path to victory, one built on sheer, unadulterated grunt. Though it was ultimately overshadowed by the championship-winning consistency of the Mazda rotaries, the Buick-powered JM19 was a fearsome contender and a true fan favorite, embodying a raw, sledgehammer approach to the technical world of prototype racing.