Borla® 40741 - XR-1™ Multicore Stainless Steel Round Race Muffler (4" Inlet / 4" Outlet)

00 reviews / Item # mpn1952134
Borla® - XR-1™ Multicore Stainless Steel Round Race Muffler
Borla® - XR-1™ Multicore Stainless Steel Round Race MufflerBorla® - Sound InformationBorla® - Exhaust Systems Sound Level Introduction on Dodge Challenger R/TBorla Authorized Dealer
● OUT OF STOCK - Unavailable until further notice
Universal Fit
Fitment Notes:
  • For All Space Allowing Race Cars Requiring the Highest Flow Muffler.
Notify Me
Interested in this item?
Have a Question? 800.505.3274
Ask a Specialist: Live Chat
Authorized Dealer:Borla
Low Prices. Price match guarantee
Guaranteed Fitment. Always the correct part
In-House Experts. We know our products
Easy Returns. Quick & Hassle Free

Product Details

Learn everything you want to know about this product
to make an informed purchase.

Borla Exhaust Systems

Universal XR-1™ Multicore Stainless Steel Round Race Muffler (40741) by Borla®, 4" Inlet / 4" Outlet, 16" Case Length x 6.25" Diameter. The Borla XR-1 Multi-Core Muffler was developed on the race track to quiet the most severe engine noise without restricting power. They work so well that they're used by race vehicles that aren't even required to have mufflers! Now you can have this advanced technology for your car.

Borla VideosBorla F.A.Q.Borla About


  • The most possible exhaust flow in a muffler for maximum performance
  • Quiets the most severe engine noise, leaving a pronounced sound of power
  • Patented straight-through, multi-core muffler design reduces backpressure while absorbing sound waves
  • Made from the finest austenitic stainless steel for long-lasting durability
  • All welded construction
  • Proudly made in the USA

In racing, every horsepower counts, so no competitor will use something that will reduce engine power. Yet, winning drivers in all forms of racing use Borla XR-1 Multi-Core Racing Mufflers. It’s because these racers have found that Borla mufflers cost them no power and in many instances, actually increase horsepower. In fact, a Borla multi-core straight through muffler has actually been found to outflow a straight piece of pipe! Most of the recent Baja off-road endurance racing champions used Borla mufflers even though the rules don’t mandate them, because they either increase or don’t reduce power, and the noise reduction reduces driver fatigue and increases driver awareness.

Borla’s patented straight through, multi-core 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.

Borla uses austenitic stainless steel in the construction of the XR-1 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. The muffler contains stainless steel perforated tubes 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.

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
  • For All Space Allowing Race Cars Requiring the Highest Flow Muffler.
Borla® - XR-1™ Multicore Stainless Steel Round Race MufflerBorla® 40741 - XR-1™ Multicore Stainless Steel...    $298.99
00 reviews
Notify Me

All manufacturer names, symbols, and descriptions, used in our images and text are used solely for identification purposes only.
It is neither inferred nor implied that any item sold by, is a product authorized by or in any way connected with any vehicle manufacturers displayed on this page.