Borla Universal Pro-XS 2.5-Inch Center Inlet / Center Outlet Polished T-304 Stainless Steel Round Specialty Muffler / Resonator with Notched Necks (400497)
Unlock ultimate exhaust flow and aggressive acoustic tuning with the Borla Universal Pro-XS Round Specialty Muffler and Resonator. Masterfully engineered to meet the demanding requirements of high-horsepower track setups, race cars, performance compacts, and customized street builds, this high-efficiency unit utilizes a bidirectional center-in and center-out 2.5-inch configuration. At its mechanical core, this premium performance muffler breaks away from restrictive traditional baffle layouts by incorporating Borla’s cutting-edge straight-through internal geometry. This innovative layout features a high-velocity perforation core that optimizes gas flow and exhaust velocity, generating an excellent scavenger effect. This advanced aerodynamic design maximizes peak horsepower, expands torque delivery, and completely eliminates backpressure bottlenecks for optimized performance configurations.
The structural engineering of the Borla 400497 addresses long-term durability and installation problems beneath harsh track and street conditions through a 100% welded, heavy-gauge setup. Enclosed in a ultra-compact 5-inch round by 10-inch long barrel case with a total 15-inch overall footprint, this robust assembly delivers excellent space optimization when tucked into tight transmission tunnels, limited-clearance chassis floors, or crowded under-car layouts where a traditional oval muffler cannot fit. The specialized straight-through body layout packs a massive volume of advanced, high-temperature Continuous-Filament Fiber (CFF) acoustic sound control packing. This advanced insulation filters out high-frequency rasp, drone, and sharp exhaust notes while preserving a raw, unrestrictive mechanical tone under full throttle. Built completely from aircraft-quality, premium-grade T-304 austenitic stainless steel finished in a natural mill texture with convenient notched neck bases, this heavy-duty canister accommodates custom brush or mirror-polished workshop textures prior to installation. Capable of being flipped or reverse-mounted due to its completely uniform, reversible internal configuration, this elite USA-made performance component delivers bulletproof structural stability backed by Borla’s legendary Million-Mile warranty.
Straight-Through Flow Dynamics & Space Optimization: Unlike basic factory replacements or restrictive multi-chambered mufflers that choke engine velocity, this Pro-XS round specialty unit features a high-flow straight-through network. The center-to-center neck configuration allows you to line up straight-line piping routes inside tight factory channels, using precise internal perforation matrices to break down high-energy sound waves without placing a physical restriction in the path of the thermal gas exit.
Fabrication Installation Guideline Note: This high-performance universal muffler is built with factory notched attachment necks engineered explicitly for clean, hassle-free clamp-on installation utilizing standard 1-inch wide band style clamps (clamps not included; use Borla clamp part number 18325 or a 3-inch wide band clamp 18004). If your project demands smooth, un-notched connection collars for a permanent weld-on workshop connection instead of a slip-fit clamp joint, see alternate part number 40842S.
Features
- High-Flow 2.5-Inch Straight-Through Core: Replaces restrictive baffled internal designs with a high-velocity path to maximize horsepower and throttle response
- Compact 5-Inch Round Profile: Space-saving round design serves perfectly as a primary muffler or inline resonator to eliminate rasp in tight spaces
- Center/Center Port Routing: Inline 2.50" connection ports allow simple adaptation into centered chassis paths and straight factory frame tunnels
- Premium Continuous-Filament Fiber: Packed with high-temp CFF insulation to absorb harsh frequencies and maintain a deep, sporty tone under load
- Factory Notched Connection Necks: Specially pre-slit for fast, secure clamp-in installation with standard 1" wide band style hardware
- 100% Symmetrical Reversible Layout: Bidirectional configuration provides ultimate fabrication flexibility, allowing it to be installed in either direction
- Heavy-Duty 100% Welded Body: Fully welded seams deliver maximum structural strength to resist extreme backfire pressures and track vibrations
- Constructed completely from premium-grade T-304 austenitic stainless steel for permanent structural integrity and ultimate rust resistance over low-grade 400-series hardware options
- Proudly Manufactured in the USA: Built in America by the world’s most experienced exhaust brand to guarantee flawless fitment and elite race-proven quality
Detailed Fitment Breakdown
Universal Application Parameters & Structural Boundaries:
This premium universal Pro-XS performance round muffler/resonator with notched necks is compatible with a massive array of custom and production vehicle platforms under the specific architectural parameters detailed below:
Universal Automotive & Custom Exhaust Fabrication Fitment:
- Integrates seamlessly into any custom aftermarket or factory replacement single or dual exhaust line running 2.5-inch piping
- Sized perfectly for compact sport cars, sport trucks, daily drivers, and custom restorations requiring a space-conscious round inline routing path
- Highly recommended for vehicle configurations requiring a mid-pipe resonator addition to tame cabin drone or exhaust rasp without robbing power
- Compatible across all domestic and import car, truck, and SUV platforms with sufficient clearance for a 5" round body footprint
Sizing, Connection & Dimensional Details:
Fits your project layout across these exact structural specifications:
- Inlet / Outlet Connection Size: 2.50-Inch internal diameter center port necks
- Muffler Case Configuration: 5.00-Inch round compact structural shape
- Muffler Case Body Length: 10.00 Inches of primary sound suppression coverage
- Overall Muffler Total Length: 15.00 Inches from inlet tip to outlet tip boundary
- Internal Architecture Matrix: Straight-through high-flow performance configuration with premium CFF sound material
- Material Grade Composition: Authentic T-304 Austenitic Stainless Steel with a natural mill finish
Important Application Notes:
- **Premium Materials:** Built entirely with authentic T-304 stainless steel to deliver superior rust resistance and durability over lower-grade T-400 series or aluminized hardware choices.
- **Versatile Fabrication Paths:** Engineered as a professional universal component with notched slip-fit necks, providing custom fabricators with a dependable, heavy-walled material block that can be easily clamped or welded if desired.
CA Residents: WARNING: Cancer and Reproductive Harm www.P65Warnings.ca.gov

