Step up your exhaust flow with the industrial-grade Dynaflex 36-4050. This premium expanding coupler is engineered to provide a high-strength, efficient transition from 4-inch components to 5-inch piping. Proudly Made in the U.S.A., it is the professional choice for heavy-duty truck repairs, diesel performance, and industrial exhaust fabrication.
Crafted from rugged 16-gauge carbon steel, this 8-inch adapter is built to handle the extreme thermal stress and high-vibration environments of commercial engines. The O.D./I.D. configuration provides a seamless "male-to-female" connection, ideal for adapting 4" turbo downpipes or mid-chassis piping to larger 5" mufflers and stacks.
Configuration: 4" O.D. to 5" I.D.
Overall Length: 8.0"
Material: 16 Gauge (.065") Carbon Steel
Origin: Proudly Made in the U.S.A.
Extended 8" Length: The generous length allows for a gradual, smooth taper. This design minimizes exhaust backpressure and turbulence compared to shorter, "stubby" adapters.
Precision Expansion: The 5.0" I.D. end is precision-expanded to slip directly over a standard 5" O.D. exhaust pipe or stack.
Versatile Inlet: The 4.0" O.D. end is sized to slip into a 4" I.D. component, such as a muffler outlet or turbo downpipe.
Weld-Ready Carbon Steel: Ships in a raw, unfinished state. This is the preferred finish for professional fabricators, as it allows for immediate, high-quality welding without the need to remove aluminized or zinc coatings.
| Feature | Specification |
| Brand | Dynaflex Products |
| Part Number | 36-4050 |
| Small End Size | 4.0" Outside Diameter (O.D.) |
| Large End Size | 5.0" Inside Diameter (I.D.) |
| Overall Length | 8.0" |
| Wall Thickness | 16 Gauge (.065") |
| Material | Raw Carbon Steel |
| Manufacturing | Made in USA |
Commercial Trucking: Transitioning 4" exhaust systems to popular 5" chrome stacks.
Diesel Performance: Building high-flow custom exhaust systems for increased horsepower.
Industrial Power: Connecting 4" generator exhaust ports to larger 5" ventilation piping.
Tech Tip: This is a raw carbon steel item. Minor surface oxidation is normal and does not affect the structural integrity or weldability of the part. We recommend applying a high-temperature exhaust paint or ceramic coating after installation to protect the exterior.
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