Borla® 40057 - Boomer™ Series Thumper Stainless Steel Oval Race Muffler (2.25" Center Inlet, 4.5" Round Tip, 14" Length)

59 reviews / Item # mpn1952109
Borla® - Boomer™ Series Stainless Steel Race Muffler
Borla® - Boomer™ Series Stainless Steel Race MufflerBorla® - Muffler SchemeBorla® - CatalogBorla® - Sound InformationBorla® - FAQBorla® - Exhaust Systems Sound Level Introduction on Dodge Challenger R/TMade In USABorla Authorized Dealer
In Stock (12) - Ships within 24 hrs
Universal Fit
Fitment Notes:
  • Not Vehicle Specific
  • To ensure precise fit, please check muffler shape, length and inlet diameter: the latter should match your exhaust pipe diameter.
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Product Details

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Borla Exhaust Systems

Universal Boomer™ Series Thumper Stainless Steel Oval Race Muffler (40057) by Borla®. Muffler Sound: AGGRESSIVE. Muffler Series: Boomer™. Muffler Structure: Multi Core. Muffler Configuration: Center - Center. Muffler Body Material: Stainless Steel. Inlet Diameter: 2.25". Outlet Diameter: 4". Muffler Body Length: 14". Muffler Body Height: 4.5". Muffler Body Width: 7.88". Muffler Body Shape: Oval. Upgrade the looks, performance and sound of your ride with just a muffler swap. These Borla mufflers increase exhaust flow and horsepower, and they come fully polished with an exhaust tip already installed. They're made of durable austenitic stainless steel and warranted for one million miles.

Notes: To ensure precise fit, please check muffler shape, length and inlet diameter: the latter should match your exhaust pipe diameter.

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  • Improves exhaust flow for better performance
  • Increases horsepower 7-10%
  • Dyno and race proven
  • Pronounced exhaust tone
  • Patented straight-through muffler design reduces backpressure while absorbing sound waves
  • Made from the finest austenitic stainless steel for long-lasting durability
  • All welded construction
  • Fully polished with exhaust tip attached
  • Backed by the exclusive Borla Million-Mile warranty
  • Proudly made in the USA

Lose your stock muffler and get increased power and performance, awesome sound and great looks. The Boomer Wailtail Stainless Steel Oval Race Muffler will improve exhaust flow, helping your engine make 7-10% more horsepower. The Boomer’s patented straight through muffler design reduces restriction and increases exhaust gas velocity, making sure each cylinder is completely evacuated to make room for the incoming charge. This design absorbs the sound waves without disturbing the power waves, in contrast to the chambered mufflers used by most aftermarket companies. Chambered mufflers use partitions or baffles to subdue sound waves, which also creates backpressure and reduces power.

But improved performance is only part of what you want in an aftermarket muffler, you also want great sound and head turning looks. There’s no need to worry with the Borla Boomer Wailtail. Borla has many years of automotive acoustical experience and the company is staffed with automotive enthusiasts just like you that listen and drive cars to make sure your muffler has the right sound to go with the power. The Boomer Wailtail has a definite “growl” that’s louder than stock without being irritating.

Borla uses austenitic stainless steel in the construction of the Boomer Wailtail muffler, which contains high levels of nickel and chromium, to resist corrosion. This material is harder than the lower grade stainless steel used by the OEM manufacturers, yet is very ductile. Nevertheless, the increased hardness requires special equipment to form and bend. Each Borla muffler contains a stainless steel perforated tube wrapped with several layers of stainless steel sound absorbing material and a layer of ceramic sound absorbing, high temperature material, all contained in a fully welded stainless steel shell. Then Borla goes the extra distance; they fully polish the muffler and install a polished 5” round exhaust tip, so you get great looks right out of the box.

Borla is so confident in the quality of this muffler that it’s guaranteed against defects in materials and workmanship for one million miles.

Borla® is the leading manufacturer of stainless steel performance exhaust products. The company began three decades ago making exhaust systems for concours classic Rolls Royce and Ferrari models, and gradually evolved to become the premier manufacturer of performance exhaust products for street, off-road and racing. Borla pioneered many improvements in the design of performance exhaust systems, holds several patents for innovative exhaust system technology, and has won numerous “Best New Product” awards. Today the company operates a state of the art research and development center in Oxnard, California, and makes all of its products at a world-class manufacturing facility in Johnson City, Tennessee.

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Warranty Information

Find out everything you need to know about the product warranty

BORLA® PERFORMANCE INDUSTRIES, INC. warrants its products to the original purchaser of record and for the original vehicle on which the product was installed, against defects in materials and workmanship for one million miles for non-moving parts. BORLA® catalytic converters are warrantied for three years. BORLA® will warranty all moving parts, such as valves and actuators for three years. This does not include blemishes or marring of appearance due to weather, road hazards, lack of maintenance or extremes of heat or cold. This warranty shall apply only if BORLA's examination of the returned product discloses a manufacturing or material defect, and BORLA's sole obligation under this warranty shall be limited to repair or replacement at BORLA's option. Note all attachment to universal mufflers must be made at the nipples; there should be no welding to the shell or end caps as this will void the warranty. No expressed or implied warranties of merchantability or fitness for a particular purpose are hereby made except as otherwise expressly provided herein. In no event shall BORLA® PERFORMANCE INDUSTRIES, INC. or any BORLA® Dealers or Distributors be liable for any loss, inconvenience or damage, whether direct, incidental, consequential or otherwise.

If you have any problems with a BORLA® product, involving either installation or performance, please call the company you bought it from immediately. BORLA® Distributors will take all necessary steps to ensure you are satisfied.

Because sound is subjective, we do not warranty for sound. Please do not return your BORLA® product if you do not like the sound level. There are several ways to adjust the sound level. You can obtain venturies, for example, from your retailer that you can place in your system to quiet your system.

If you must return part or all of your purchase to your retailer, call first. If for any reason your retailer must return part of your purchase to us, he will need information, including a customer service number, to speed shipment and processing, so that we can get your purchase back to you as quickly as possible.

When returning your purchase, include a copy of this warranty with the product, along with your name, address, telephone number with area code, a description of the problem and proof of the date of retail purchase (invoice copy). Return the product, freight charges prepaid. Pack carefully; we cannot accept product damaged in shipment.

This warranty does not include the cost of removal or reinstallation of the product, and does not apply if the product has been damaged by accident, abuse, misuse, or misapplication. This warranty is valid for BORLA® street-legal products only and does not apply to any racing products or street products used for racing purposes. Any modifications to the product or its intended use voids the warranty. No person or representative is authorized to extend any warranties on behalf of BORLA®, other than the warranty expressed herein. Some states do not allow limitations on how long an implied warranty lasts, so the above limitations may not apply to you. Some states do not allow the exclusion of limitations of incidental or consequential damages, so the above limitations or exclusions may not apply to you. This warranty gives you specific legal rights, and may have other rights which vary from state to state. This warranty replaces all previous warranties.

This warranty excludes XR-1® Raceline products and Marine products.

Products sold outside the USA carry a 3-year limited warranty.

Magnuson-Moss Warranty Act:
Legally, a vehicle manufacturer cannot void the warranty on a vehicle due to an aftermarket part unless they can prove that the aftermarket part caused or contributed to the failure in the vehicle (per the Magnuson Moss Warranty Act (15 U.S.C. 2302(C)) Learn More

Vehicle Fitment

This part is universal
Year Make Model Fitment Notes:
ALL       ALL        ALL         This part is universal

    Product Reviews


    Every Customer can leave a review about our service and the product that was purchased. In order to leave your review for your new product, please follow the link in the email you receive after completing your purchase. You can rate appearance, ease of installation, price/value and product quality.

    Borla® - Boomer™ Series Stainless Steel Race Muffler
    Borla® 40057 - Boomer™ Series Thumper Stainless Steel Oval Race Muffler (2.25" Center Inlet, 4.5" Round Tip, 14" Length)
    Average Rating: 4.8 of 5
    5 of 5
    Borla Boomer Waitail
    Sounds and looks great on my car!
    CPosted by (St Thomas, VI) /
    2008 Toyota Corolla
    Was this review helpful for you? Yes3  people found this review helpful.
    4.5 of 5
    Easy to install and great sound, I completely satisfied.
    CPosted by (Grand Forks, ND) /
    Was this review helpful for you? Yes1  person found this review helpful.
    5 of 5
    Very Satisfied with the Product
    Good looking - Installed easily - Worth the money - Very good quality.
    WPosted by (Myrtle Beach, SC) /
    Was this review helpful for you? Yes3  people found this review helpful.
    4.3 of 5
    Borla-Boomer Spit Fire Muffler
    Great sounding muffler. Easy to install.
    SPosted by (Mount Joy, PA) /
    Was this review helpful for you? Yes5  people found this review helpful.
    5 of 5
    Borla Boomer Blow Muffler
    This is everything I had expected. I have a 2005 Subaru Impreza. The muffler woke up my little Subbie. The sound and performance are great!
    GPosted by (China Village, ME) /
    Was this review helpful for you? Yes7  people found this review helpful.
    4.8 of 5
    Borla Boomer Rock-it Muffler
    Awesome deep sound... Great value. Received shipment days before it was supposed to get here. Recommended for anyone who wants something more than that cheap muffler sound.
    NPosted by (Tijeras, NM) /
    Was this review helpful for you? Yes7  people found this review helpful.
    4.3 of 5
    Sexy Broom Broom Sound!
    When I turned on my car and heard my new exhaust booming, immediately I was impressed! I love this muffler. Outta of a scale from 1-10, I definitely rate it off the scales, that's how good it runs and looks. Anyone out there that is looking into getting this product, Get It Now! You will be happy you did...I can tell you it'll be well spent.
    CPosted by (Killeen, TX) /
    Was this review helpful for you? Yes11  people found this review helpful.
    5 of 5
    Lexus ES 300
    Borla® - Boomer™ Thumper Stainless Steel Oval Race Muffler
    This product was absolutely outstanding. It makes the perfect deep sound. Plus, my mechanic had no problems with installation. I will be back to buy Borla parts definitely.
    WPosted by (Warren, NJ) /
    Was this review helpful for you? Yes8  people found this review helpful.
    5 of 5
    Borla® - Boomer™ Thumper Stainless Steel Oval Race Muffler
    Got that deep sound that I was looking for!
    CPosted by (Colts Neck, NJ) /
    Was this review helpful for you? Yes8  people found this review helpful.

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