Borla Universal Pro-XS Dual 2.25-Inch Inlet / Dual 2.25-Inch Outlet Polished T-304 Stainless Steel Oval Muffler with Internal X-Pipe and Notched Necks (400492)
Unlock ultimate exhaust flow and aggressive acoustic tuning with the Borla Universal Pro-XS Muffler. Masterfully engineered to meet the demanding requirements of high-horsepower track setups, race cars, performance trucks, and customized street builds, this high-efficiency unit utilizes a bidirectional dual-in and dual-out 2.25-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 combined with an integrated crossover network. This innovative layout features an internal X-pipe assembly that balances exhaust pulses, optimizes gas flow, and enhances scavenging across both engine banks. 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 400492 addresses long-term durability and installation problems beneath harsh track and street conditions through a 100% welded, heavy-gauge setup. Enclosed in a compact 4-inch by 9.5-inch oval by 19-inch long barrel case with a total 24-inch overall footprint, this robust assembly delivers excellent space optimization when tucked into narrow transmission tunnels, low-clearance chassis floors, or crowded under-car layouts. The specialized straight-through dual body layout packs a massive volume of advanced, high-temperature Continuous-Filament Fiber (CFF) acoustic sound control packing around the crossover core. This advanced insulation filters out high-frequency rasp and annoying highway cabin drone 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 unit features a high-flow straight-through network containing an internal X-pipe crossover. The dual-to-dual neck configuration allows you to line up true dual crossover layouts inside tight factory channels, using precise internal perforation matrices to break down high-energy sound waves and balance exhaust bank pressure 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 18322). 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 400287.
Features
- Integrated Internal X-Pipe Crossover: Equalizes cylinder bank exhaust pulses to maximize scavenging efficiency, engine power, and acoustic balance
- High-Flow Straight-Through Dual Core: Replaces restrictive baffled internal designs with a high-velocity path to maximize horsepower and throttle response
- Dual/Dual Port Routing: Symmetrical dual 2.25" inlets and outlets accommodate full true-dual exhaust setups without needing standalone crossover pipes
- 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 muffler 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 true dual exhaust line running 2.25-inch piping
- Sized perfectly for V6 and V8 muscle cars, street rods, trucks, and SUVs looking for a built-in X-pipe crossover replacement inside a single muffler case
- Highly recommended for vehicle configurations requiring an efficient dual-in/dual-out layout to save space underneath crowded subframes and chassis floors
- Compatible across all domestic and import car, truck, and SUV platforms with sufficient clearance for a 4" x 9.5" oval body footprint
Sizing, Connection & Dimensional Details:
Fits your project layout across these exact structural specifications:
- Inlet Connection Size: Dual 2.25-Inch internal diameter port necks
- Outlet Connection Size: Dual 2.25-Inch internal diameter port necks
- Muffler Case Configuration: 4.00-Inch x 9.50-Inch traditional oval structural shape
- Muffler Case Body Length: 19.00 Inches of primary sound suppression coverage
- Overall Muffler Total Length: 24.00 Inches from inlet tip to outlet tip boundary
- Internal Architecture Matrix: Straight-through performance design with built-in X-pipe and 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
