Borla XR-1 Multi-Core Racing Muffler, 3-Inch Center Inlet and Outlet, Part Number 400372

XR-1(r) Multi-Core Racing Muffler. 3" Center Inlet/ 3" Center Outlet 4.25" x 7.88" Oval x 12" Long Body 17" Overall Length. Compact size is perfect for applications with limited space and can be used on a wide range of vehicles. It features BORLA(r)'S patented Multi-Core 4 tube design for maximum flow, horsepower, and torque. The Multi-Core portion of XR-1(r) mufflers flows better than straight tubing. Recommend for high horsepower applications. Reversible design for installation flexibility. T-304 Stainless steel for superior corrosion resistance. Natural mill finish can be brushed or polished prior to installation. 100% welded construction for strength. High-temperature continuous-filament fiber (CRF) acoustic material for sound control. There is no BORLA(r) logo embossment on this part. Best of all, it's made in the USA. Just what you’d expect from the world’s most experienced (and most winning) exhaust brand. XR-1 Multi-Core Racing Muffler Rotary Engine Equipped Vehicles - 3" Center Inlet/ 3" Center Outlet 4.25" x 7.88" Oval x 12" Long Body 17" Overall Length. Universal Part. Reversible Design. Patented Multi-Core Technology

• 3" Center Inlet/ 3" Center Outlet 4.25" x 7.88" Oval x 12" Long Body 17" Overall Length
• Universal muffler. Reversible design. No BORLA(r) logo embossement.
• Compact design is perfect for applications with limited space
• Can be used on a wide range of vehicles
• Multi-Core 4 tube internal design

The Borla XR-1 Multi-Core Racing Muffler is a compact, universal exhaust solution engineered for high-performance and high-horsepower applications, including rotary engine-equipped vehicles. With a 3-inch center inlet and 3-inch center outlet, this reversible muffler provides installation flexibility when space is limited. Its oval body design supports versatile placement across a wide range of custom exhaust systems.

At the core of the Borla XR-1 is patented Multi-Core technology featuring a four-tube internal design. This configuration is engineered to promote high exhaust flow while supporting strong horsepower and torque performance. Borla recommends the XR-1 for demanding racing and performance applications where efficient exhaust flow and compact packaging are important. High-temperature continuous-filament fiber acoustic material helps control sound without relying on restrictive internal construction.

Constructed from T-304 stainless steel, the Borla Part Number 400372 offers excellent corrosion resistance and long-term durability. Its 100% welded construction adds structural strength, while the natural mill finish may be brushed or polished before installation. The muffler is made in the USA and uses a universal, reversible design for custom fabrication. This part does not include a Borla logo embossment. Professional installation or custom exhaust fabrication is recommended to ensure proper alignment, clearance, and secure attachment.

Product Specifications and Technical Data

• Brand: Borla
• Part Number: 400372
• Product Type: Universal racing muffler
• Inlet Size: 3 inches
• Outlet Size: 3 inches
• Body Shape: Oval
• Internal Technology: Patented Multi-Core four-tube design
• Construction Material: T-304 stainless steel with 100% welded construction

What's Included

One Borla XR-1 Multi-Core universal racing muffler. Inlet and outlet piping, clamps, hangers, gaskets, and installation hardware are not included unless supplied separately.

Fitment: Universal application for custom exhaust systems and rotary engine-equipped vehicles. Verify inlet, outlet, clearance, and fabrication requirements before purchase.

Features:

• Compact design: Fits performance exhaust applications where installation space is limited.
• Patented Multi-Core technology: Four-tube internal construction is engineered for high flow and strong horsepower and torque performance.
• Reversible universal design: Center inlet and outlet configuration allows flexible installation and custom exhaust placement.
• Durable stainless-steel construction: T-304 stainless steel, 100% welded construction, and high-temperature acoustic fiber provide durability and sound control.

Air Freight Prohibited: false
Not Carb Approved: false
Ltl Freight Required: false
Prop 65: Y
Part Type: automotive
Epa: N/A
Carb Acknowledgement Required: false
Regular Stock: t
Units Per Sku: 1