Aluminum Race Mufflers We offer 4different sizes of USA made 6061 aluminum race mufflers. These light weight and compactaluminum mufflers are constructed from T6061-T6 aluminum, with TIG-welded seams andfeature a straight through design. This straight through design gives asignificant noise reduction without performance loss. When ordering thesealuminum race mufflers, make sure to see our welding supplies for aluminumfiller rod, abrasives and welding how to videos.