Borla XR-1 Multicore Racing Muffler

The Borla XR-1® Multicore Racing Muffler line represents the pinnacle of race-bred exhaust technology, trusted by drag racers, oval track competitors, and high-horsepower performance builders. Engineered exclusively for serious racing applications, the XR-1 series delivers a proven combination of unrestricted flow, effective sound management, and race-tough durability that no other muffler on the market can match.

At the core of every XR-1 muffler is Borla's patented Multicore uninterrupted-flow technology — an internal design that has been proven in repeated testing to actually outflow a straight piece of pipe. This breakthrough means racers can gain maximum horsepower and torque without sacrificing the sound attenuation required at competitive venues. In fact, in some cases Borla's XR-1 mufflers have been shown to improve horsepower over an open pipe.

Key Features:

• Patented Multicore uninterrupted-flow design — proven to outflow a straight piece of pipe for maximum power and torque
• Aircraft-quality T-304 stainless steel construction — lightweight, austenitic alloy that will never rust, built for the most demanding race environments
• 100% welded, one-piece construction — all-welded design for superior structural integrity and zero leak points
• High-temperature sound-absorbing packing — T-304 stainless steel wool or high-temperature Continuous Filament Fiber (CFF) depending on configuration, providing effective sound control while protecting against burnout
• Reversible design — flexible installation orientation to accommodate a wide range of exhaust routing configurations
• Universal fitment — available in multiple body styles and inlet/outlet configurations to suit virtually any racing application
• Clean, no-embossment shell — natural mill finish that can be brushed or polished prior to installation for a professional appearance
• Made in the USA — manufactured by the world's most experienced and most winning exhaust brand

The XR-1 Multicore line spans multiple variants — including round-body, slim-line oval, Sportsman, and Bullet configurations — offering solutions for everything from tight-clearance rotary engine builds to full-bodied circle track cars and hard-launching drag applications. Whether your venue requires a muffler or you're simply chasing the fastest elapsed time possible, Borla's XR-1 series delivers the ideal balance of sound control and unrestricted performance. Select the specific variant below that matches your inlet size, body style, and application requirements.