Borla CrateMuffler Resonator Option BOR400939, 3-Inch Center Inlet/Outlet

Perfect for applications with limited space. If you want to lower the sound pressure level (SPL) of your CrateMuffler(r)s, you can install this resonator. This compact bottle / bullet style resonator can also be used as a universal resonator in any system of this diameter. The Resonator is designed to attenuate overall sound. This is perfect for customers looking to reduce the sound level 2-3 dB(A). This straight-through design will not degrade the performance of your vehicle. Resonator dimensions 3" Center Inlet/ 3" Center Outlet, 4" Round, 10" Long Body 15" Overall Length. Un-Notched necks are designed for weld in installation. If clamping, use 3" wide band clamps 18006. Reversible design for installation flexibility. High-quality T-304 austenitic stainless steel for superior corrosion resistance. 100% welded construction for strength. Free Flow design for improved performance. High-temperature continuous-filament fiber (CFF) acoustic material for sound control. Natural mill finish can be brushed or polished prior to installation. There is no logo embossment on this part. Best of all, it's made in the USA and backed by BORLA(r)'s Million-Mile warranty. Just what you'd expect from the world's most experienced (and most winning) exhaust brand. Resonator - Sound Level N/A Resonator - 3" Center Inlet/ 3" Center Outlet 4" Round x 10" Long Body 14" Overall Length Universal Part Reversible Design.

• Un-Notched necks are designed for weld in installation. If clamping, use 3" wide band clamps 18006.
• Use with BORLA(r) S-Type CrateMuffler(r) to achieve the Touring sound level
• Universal bottle / bullet style resonator. Reversible design.
• Compact size is perfect for applications with limited space

The Borla CrateMuffler Resonator Option BOR400939 is a compact, universal bottle-style resonator designed for exhaust systems with limited installation space. Its 3-inch center inlet and 3-inch center outlet provide broad compatibility with exhaust tubing of the same diameter. The reversible design allows flexible orientation during installation, while the straight-through configuration helps reduce overall sound without restricting exhaust flow or degrading vehicle performance.

Designed to lower sound pressure levels by approximately 2–3 dB(A), this Borla resonator is an effective choice for refining exhaust tone and reducing unwanted volume. It can be used as a universal resonator in a properly sized exhaust system or with a Borla S-Type CrateMuffler to help achieve a Touring sound level. The un-notched necks are intended for weld-in installation; for clamped installations, use 3-inch wide-band clamps such as Borla 18006.

Constructed from high-quality T-304 austenitic stainless steel, the BOR400939 delivers excellent corrosion resistance and long-term durability. Its 100% welded construction supports strength under demanding exhaust-system conditions, while high-temperature continuous-filament fiber acoustic material provides reliable sound control. The natural mill finish may be brushed or polished before installation. Made in the USA and backed by Borla's Million-Mile Warranty, this resonator provides dependable sound management for automotive exhaust applications. This part has no logo embossment and is not a vehicle-specific fitment; verify tubing diameter and available space before installation.

What's Included

One Borla CrateMuffler Resonator Option BOR400939. Installation hardware and clamps are not included.

Fitment

Universal automotive fitment for exhaust systems using 3-inch tubing. Professional installation is recommended. California emissions approval does not apply to this component, and Proposition 65 requirements may apply.

Features:

• Compact bottle-style resonator is well suited to exhaust systems with limited space
• Straight-through, free-flow design helps reduce sound while maintaining exhaust performance
• Reduces overall sound pressure by approximately 2–3 dB(A) for a more controlled exhaust tone
• Reversible 3-inch center-inlet and center-outlet configuration supports flexible universal installation

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