The Borla XR-1 Multi-Core is a long-body racing muffler with a 3in center inlet and 3in center outlet on a 6.25in round body (16in body, 21in overall). Its patented Multi-Core 4-tube design flows better than straight tubing for maximum horsepower and torque, and the long body suits SUV and truck builds. T-304 stainless with CFF packing, a reversible design and no logo embossment.
| Type | XR-1 Multi-Core racing muffler |
| Inlet/Outlet | 3in inlet / 3in outlet |
| Configuration | Center / Center |
| Body | Round - 6.25in diameter - 16in body - 21in overall |
| Core | Patented Multi-Core 4-tube |
| Material | T-304 stainless steel - 100% welded - no embossment |
| Part Number | 400373 |
Shipping: In-stock orders placed before 4 PM EST ship the same day, with standard, expedited, and overnight options available at checkout. Backordered items ship as soon as our distributor restocks — contact us for lead times. See the full Shipping Policy.
Returns: 30-day returns on new, unused items in original packaging. See the full Refund Policy.
