Borla® 40057 - Boomer™ Thumper Stainless Steel Oval Race Muffler

52 reviews / Item # mpn1952109
Borla® - Boomer™ Thumper Stainless Steel Oval Race MufflerBorla® - Boomer™ Thumper Stainless Steel Oval Race MufflerBorla® - Sound InformationBorla® - Exhaust Systems Sound Level Introduction on Dodge Challenger R/TBorla Authorized Dealer
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Universal Fit
Fitment Notes:
  • Not Vehicle Specific
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Borla Exhaust Systems

Universal Boomer™ Thumper Stainless Steel Oval Race Muffler by Borla®, 2.25" Inlet, 4.5" Thick x 7.88" Wide x 14" Case Length, and 4" Side Round Tip. 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.

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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 Thumper 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 Thumper. 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 Thumper has a definite “growl” that’s louder than stock without being irritating.

Borla uses austenitic stainless steel in the construction of the Boomer Thumper 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 4” 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.

Part Number:

Vehicle Fitment

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

    Product Reviews


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    Borla® - Boomer™ Thumper Stainless Steel Oval Race Muffler
    Borla® 40057 - Boomer™ Thumper Stainless Steel Oval Race Muffler
    Average Rating: 5 of 5
    5 of 5
    Posted by (Warren, NJ) /

    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.

    Was this review helpful for you? Yes8   people found this review helpful.
    5 of 5
    Posted by (Colts Neck, NJ) /

    Got that deep sound that I was looking for!

    Was this review helpful for you? Yes8   people found this review helpful.
    Borla® - Boomer™ Thumper Stainless Steel Oval Race MufflerBorla® 40057 - Boomer™ Thumper Stainless Steel...    $191.99
    52 reviews
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