How much horsepower can I expect to gain?
An engine is an air pump, and BORLA's exhaust system allows the engine to pump and flow more uninterrupted air. The actual horsepower increase depends upon the fuel management system's ability to provide the right amount of fuel to match the extra air flow; 5 to 15% increases are not uncommon. Under racing conditions, BORLA's XR-1® collector mufflers actually make more horsepower than an open exhaust!
How does FLOW affect performance and sound?
BORLA exhaust systems' patented, straight-through design increases exhaust gas velocity and moves more uninterrupted air through the engine. Since there are no restrictions, exhaust gases evacuate the cylinder completely, thereby allowing the new charge to come into the cylinder and create more power. The result is a larger volume of torque from the engine as well as an enhanced exhaust tonal quality.
Will I get better gas mileage?
Yes, a better performing engine uses less fuel more efficiently, increasing fuel economy under normal cruising conditions. BORLA's patented flow through design and proper diameter mandrel bent tubing evacuate the exhaust gases out of the system much faster and at a much greater temperature than factory exhaust. This results in performance gains in horsepower when you plant your foot and fuel economy at cruising speeds. And, the bigger the vehicle, the bigger the engine, the bigger the load, the bigger the savings in fuel. That's why UPS delivery trucks are BORLA-equipped!
Why does it cost more?
The most commonly used metals in the manufacture of exhaust systems are rusty mild steel, aluminized steel or an inferior 400-series stainless. BORLA uses only high quality austenitic stainless steel. It costs more than the other lesser grades of steel. To cut, bend and hand weld this grade of stainless steel takes special equipment, too. Ask your local muffler shop if they can make a smooth, precision mandrel bend in a 2.50" 201 or 300 Series Stainless Steel pipe for you. You won't find many that can, and it won't be cheap. BORLA also focuses heavily on research and development to assure that the system fits, performs and sounds better than any other system on the market. Add to this pressure testing, the Million-Mile Warranty and the years of race winning technology that go into the systems made at BORLA, and you will see why BORLA has so many loyal, repeat customers. A BORLA is actually very cost effective when you take into account the fact that most exhaust systems will need replacement within 18 months to 4 years while a BORLA exhaust is designed to last the life of your vehicle.
What does it sound like?
BORLA Cat Back™ systems have a deeper, throatier tone than stock. Their engineers take care in designing and tuning these systems with the mellow sound of power, aggressive yet elegant. Picture yourself driving down the road and turning up the bass on your stereo system, but not changing the volume. That's what BORLA sounds like!
Will it void my factory warranty?
NO. Some cars even have BORLA systems as the OEM exhaust. All of BORLA's street Cat-Backs™, Rear Sections and Mufflers are 50-state emissions legal. In fact, it is illegal for a dealer to deny you the OE warranty because you have changed the exhaust system.
If your vehicle manufacturer fails to honor emission/warranty claims, contact the EPA at (202) 260-2080 or If federal warranty protection is denied, contact the FTC at (202) 326-3128 or
Is a bigger pipe and muffler system better?
No, there has to be a balanced design to enhance the maximum engine output, exhaust gas velocity, and sound. If the diameter of the tubing is too large, the exhaust gas velocity will be reduced and rob the exhaust of thermal efficiency. BORLA often disproves accepted racer mentalities like bigger is better. They must spend a great deal of energy explaining to someone how a 4" exhaust pipe will not work as efficiently as a 3" pipe. That is hard sometimes, but it is why there are magazine editors. Even with BORLA's excellent "track record", winning more professional car races than all the other muffler makers combined, they still often have to prove their theories to very well-known top racers. One of these issues is volume versus velocity. The late John Lingenfelter helped BORLA prove this over and over with his legendary Corvette exploits. People were often amazed how he would run 600 plus horsepower Vettes with 2 1/2" exhaust. If 4" would have made John go faster, he would have run it. There needs to be a pipe large enough to overcome the boundary layer restriction in a dynamic flow situation while maintaining exhaust speed and evacuation. This isn't a simple axiom to understand, but the second best explanation is to say in race classes, where let us say the budgets are seldom limited and the rules are not restrictive regarding exhaust, you will observe much smaller exhaust header tubing and exhaust pipes than some kids run on their 190-horsepower hand-me-down Honda sports compacts on the street.
My new car came with Stainless Steel exhaust from the factory! What's the difference?
Material Difference: Many new-model cars and trucks come factory-equipped with a low grade, 400 series stainless steel exhaust. These are an improvement from the old, rusty steel systems and are built to improve durability somewhat. Also, the inferior grade of stainless is the only cheap material that will last through the factory warranty period. But, ferritic stainless steels, which are part of the 400 series of stainless alloys, are magnetic, as compared to Austenitic stainless steels, which are part of the 200 & 300 series of stainless alloys and are non-magnetic. BORLA incorporates Austenitic stainless, which is superior for automotive exhaust because it exhibits higher hardness and yield strength as well as excellent ductility. And, the higher nickel and chromium content makes it much more resistant to corrosion. Because these austenitic alloys are higher grade materials and harder to work with, they are therefore too expensive for the OE to supply. High quality, austenitic stainless allows BORLA to back their systems with a Million-Mile guarantee - A BORLA is a lifetime system!
Performance Difference: BORLA exhausts are also tuned to maximize the performance output of your vehicle and feature a more attractive and cost effective package than stock.
Can I install a BORLA system myself?
Yes, many of our customers enjoy installing their BORLA system. In fact, we are told all the time that it's a tougher job to remove the stock system than to install their BORLA! Just be sure you have good clearance and access under your vehicle, have the proper tools, observe standard safety procedures, and ensure the vehicle is secured by approved jack stands. We do, however, recommend you have a professional installer do the work, especially for a header installation, which requires more skill. And note BORLA Cat-Back™ and Axle-Back exhaust systems are engineered to bolt to factory mounting locations and are therefore not recommended for vehicles that have been highly modified. Vehicles that have been highly modified may experience fitment issues.
Do I need to make any modifications to my vehicle to install the system?
BORLA Cat-Back™ and Axle-Back exhaust systems are designed and engineered to bolt to factory mounting locations, and necessary installation hardware is included in the kit. Therefore, they are not recommended for vehicles that have been highly modified. Vehicles that have been highly modified may experience fitment issues.
Is the BORLA product different from a 'glass pack' design?
Yes. A glass pack is a muffler usually containing a cheap grade of loose fiberglass insulation in a louvered tube. A byproduct of combustion is water, which combines with the expelled gases forming a variety of very corrosive acids. These acids get absorbed by the fiberglass packing and attack the louvered core. This in turn causes the core to rust and blow out along with the other internals of the glass pack. All that is left is a loud, empty can. BORLA mufflers, on the other hand, contain high quality, austenitic stainless steel perforated pipe wrapped with several layers of stainless steel sound absorbing material and a blanket of ceramic sound absorbing, high temperature material. The stainless steel inner construction, which is impervious to all corrosive acids, protects the ceramic packing from breaking down and getting blown out, so a BORLA muffler never needs replacing. In addition, a BORLA muffler is the most effective sound-absorbing device for the size, and it is guaranteed for one million miles.
Are XR-1® exhaust products street legal?
Yes, when selected for the appropriate application.
Why is BORLA exhaust so much better than other brands?
BORLA is the original. BORLA pioneered the use of high-quality austenitic stainless steel in exhaust manufacturing over 30 years ago. Alex Borla holds five US patents for innovative, revolutionary exhaust technology. These patented, award and race-winning designs are unbeatable in terms of flow, sound, fit, durability and guarantee. A BORLA muffler actually flows better than a straight pipe. This also translates to fuel economy.
Bottom line - all other exhaust products are copycats at best; the cliche is true: "Often imitated, never duplicated". Why buy a wannabe when you can own an original? BORLA has made a 3 decade long commitment and continues to lead the pack with performance gains, quality materials, craftsmanship, a distinctive look and sound, and a Million-Mile Warranty. BORLA is not a trendy, here today-gone tomorrow company or product. Whether you drive a Ferrari, Camaro, F-150, Jeep, PT Cruiser, or Civic, BORLA is the exhaust your vehicle deserves.
Some of the engine builders who rely on BORLA to give them the competitive edge are: Greg Davis, Keith Dorton, Kenny Duttweiler, Ernie Elliott, Ryan Falconer, Tony Feil, Dennis Fischer, Earl Gaerte, Ron Hutter, Sonny Leonard, Lingenfelter Performance, Pat Musi, David Nickens, Roush Racing, Saleen, Steeda, Ron Shaver and Robert Yates.
Racing champs who know the benefits of running BORLA's and trust BORLA to be the quickest and quietest to give them the winning advantage include Kenny Bernstein, Brandon Bernstein, G.S. Abbott, Jean Ann Campagna, Steve Echols, Kent Hanley, Alan Kenny, Pat Musi, Wayne Talkington and Jeff Strickland as well as the American LeMans Corvette Racing Team, GM Racing's Cadillac LMP Team and Team Lexus. BORLA has been invited to participate in Toyota racing programs as well as Team Viper's GTS-R, Team Escort, and Team Focus programs from their inceptions. BORLA "rules" the NHRA in exhaust; and sponsors the Speedvision GT and touring class cars. BORLA has enjoyed some 20 years of mutually beneficial relationships with the OEM (Original Equipment Manufacturers). They participate in the design and build up of many concept vehicles for Chrysler and Ford as well as GM, TRD, Mazda, Nissan, and Lexus. Ford Motor Company chose BORLA exhaust for their limited Cobra-R model. Ford's national dealer training videos have featured BORLA project vehicles. BORLA developed a complete exhaust system, including headers, for the Shelby Series I and has worked with Toyota and their Solara as well as Mazda and their Protege on both aftermarket opportunities and limited production runs.
Top engine builders, top winning racers, car manufacturers, and automotive enthusiasts worldwide recognize the difference BORLA makes. You will too.
Why doesn't BORLA have sound clips?
Although BORLA has posted a few sounds on their website homepage, it's really a disservice to the actual sound quality of their products because they sound so much better in person - no matter what kind of computer speakers you have. The following are some reasons you shouldn't trust sound clips.
Recorded with a microphone. There are thousands of different microphones available and they all sound different from one another. Record the same system, on the same car, with different microphones and the sound will be different. Variables of condenser mics, dynamic mics, large capsules, small capsules, tubes etc. will all affect the sound you hear on playback. Are you looking to compare microphones or exhausts?
A compressed sound file - Sound files are normally compressed for web pages and this drastically changes the sound.
Played back through a speaker - Similar to the microphone issue listed in item #1, there are a wide variety of speakers available and they all sound different. The difference in speakers will completely change the sound you hear on playback. Add a subwoofer and it's even less of a true replication of what you will experience after you have installed a BORLA on your vehicle. We wouldn't recommend making your buying decision by listening to sound clips on the web. It's like deciding who has the best tomato sauce by recreating the smell they emit with scratch-and-sniffs. There is no substitute for tasting it. When you hear an exhaust in person, there are certain physical properties of sound that are impossible to recreate with a sound file, such as vibration through the ground and into your inner ear. The sound you hear from BORLA's Corvette exhaust, for example, is not just what comes out of the tailpipe. It's rather a combination of sounds coming from the tailpipe tip, the engine, reflections off the ground, resonance of the cabin - even the reverberation of sound through your body affects what you hear through your inner ear. You can't recreate all of these variables over the Internet, yet they all affect the sound experience of your exhaust. Therefore, whatever you hear over cyberspace cannot be an accurate replication of what you will hear when you install it on your Vette for real. If you're as critical of sound as BORLA is, this is unacceptable.
BORLA Performance strives for opportunities to match up against the competition in real world settings because, after nearly 30 years of success and customer feedback, they have a very good idea of what their customers are looking for.
Although it's fun (and certainly easy) to surf the web and listen to sound clips, we wouldn't recommend using this to decide which exhaust system to buy.
What makes austenitic steel the best choice for an exhaust upgrade?
BORLA Performance stands behind their products by offering a lifetime warranty against defects in materials and workmanship. After nearly 30 years, the reason they are able to do this is because austenitic stainless steel is a superior material with optimum chromium and nickel content to maximize resistance to corrosion and rust as compared to 400 series which contains iron that, as we all know, rusts.
For example, the stock headers on some cars have been made of 400 series stainless for some time. Look at one sometime and see how badly they rust. Do you want to buy an aftermarket exhaust system made of the same material?
The Society of Automotive Engineers (SAE) has reported the overwhelming advantages of 300 and 200 series stainless steel over lesser grades like 400. Be clear on your comparisons. Buy the performance upgrade. Buy the quality materials upgrade. Buy the BORLA.
What procedure or formula does BORLA use to determine the perfect muffler sound?
This is a combination of experience, equipment and savvy. BORLA is confronted with different parameters depending on the application. For example, they make a significant number of OE systems, and each manufacturer has different criteria: Ford Racing may want an aggressive Mustang system while another may be looking for a more subdued sound or vice versa. They are also governed by federal and state regulations regarding emissions and sound. Fortunately, thanks to SEMA, they now have (in most states, including California) a db number for sound which is 95db. BORLA uses the SAE J1169 testing procedure. BORLA is most well known for making a very mellow growl rather than a painful bark. They do this while providing a gain in power and performance due to the technology of the entire system.
Explain the interaction of sound, pressure and heat waves in muffler design.
The critical factor to understand is that these three energy waves are emitted at different speeds and frequencies. Like any sound wave, they must be absorbed or interfered with to be diluted. The straight through designs that BORLA pioneered dramatically reduce back pressure while eliminating significant sound waves. A portion of this effort is proprietary, even to the level of allowing Alex Borla multiple patents for his unique methods of acoustical sound wave attenuation in an internal-combustion engine muffler. This being said, some of the characteristics they can share. The biggest secret is use of multiple cores in their high end street and racing mufflers. This also is patented technology. Another component is the quality of the materials used. Some companies try to cut corners by making the shell out of a higher quality stainless steel then using mild steel or cheaper 400-series stainless inside. These materials are not conducive to long term use in the stressful environment found in today's mufflers. One of the reasons is that today's engines are very lean and clean, creating a much hotter exhaust stream. Features for which BORLA is known include the special perforated core developed around significant testing as well as the special packing materials BORLA incorporates. The use of these components is both costly and requires special equipment to assemble their mufflers. Alex Borla has been at the forefront of both performance exhaust systems and assembly equipment for nearly 30 years. BORLA utilizes high quality austenitic stainless steel for everything, including the steel wool packing material. Costly? You bet, but extremely effective and durable. So the secret is to absorb the sound waves and not disturb the power waves. All this while insulating any heat sinked by the muffler.
What is the decibel limit for street applications? Are laws Local or Federal?
95db in most states using the SAE standard J1169. Some municipalities have restricted this even more dramatically. BORLA builds to this number for the aftermarket. Their OE customers may have a different number.
What are the most common muffler technologies on the market, and how do they work?
The most common method is to chamber the exhaust gases. This is used by most of the OEM as it is simple and inexpensive. The sound waves hit a partition, or baffle, and bounce back into themselves or another wall to kill the sound. Effective, but this method also creates backpressure and reduces power. This is almost a parasitical power loss and is incorporated by numerous aftermarket muffler builders. It doesn't take a degree in physics to understand that while the sound wave is being interrupted, so is the pressure or power wave. Thus a power loss will incur. It also makes a very hot muffler and often is the reason for resonance inside the cockpit.
Is all sound cancellation technology the same?
While some companies claim breakthroughs in everything from NASA acoustical engineering to mathematically derived counter angles, BORLA has never been able to prove any of their theories without dramatic increases in weight and/or cost. Their R&D engineers purchase their competitors' systems and give them all the tests - flow, horsepower, weight even including full cut-away dissections and evaluations of methods and materials. While BORLA has been at the top of the high end exhaust equipment pyramid for nearly 30 years, they keep abreast of parallel technology. They never sit still. Alex Borla still spends time in all the shops looking for the next better mouse trap. He hires people with education and experience who are not afraid to think outside of the box.
Do bigger muffler pipes alter sound? If so, how?
The larger the muffler pipes, the more sound will pass through with the power wave. Big pipes make more sound. A certain amount of this sound can be absorbed by utilizing a longer muffler, but at some point this becomes both expensive and heavy. BORLA often use XR-1® mufflers that are over 30" long for serious, Pro off-road trucks. This is double the length of their popular street car mufflers and almost three times longer than, say, a Corvette S-style system. Trophy trucks have no requirement regarding mufflers, but almost everyone runs them. In fact, every Baja winner and SCORE off-road race winner and champion for the last three years has run BORLA's. BORLA pays no contingency, and these teams spend millions on their efforts. It is the F-1 of off road. Most teams have $250,000 chase trucks and several 18 wheelers as well as one or two helicopters for these races. They don't want to give up power, but they want to hear the radios. They also say after a horrific Baja 1000 they feel twice as refreshed after the race with the BORLA mufflers on. In fact Alan Pflueger, the flyin' Hawaiian, drove his Monster Energy Drink Trophy Truck the entire Baja by himself and credits a portion of that to the quieter mufflers BORLA built for him.
Why does a pushrod Chevy V8 sound different from a pushrod Ford V8 engine? Is it the firing order?
In most cases, the angle of the short turn radius of the exhaust port creates the sound difference - that is if all other components are equal (cubes, cam, compression, etc.). The speed of the exhaust as it rolls over the short turn and gains speed from the valve makes most of the noise in an engine. This is a sonic boom that is relative to the speed of the moving air. Thus, a high compression engine will sound louder, even at an idle. The same is true with a supercharged engine of the same compression.
Does BORLA have a bionic ear at their company? If so, whose ear has the final say-so on muffler sounds?
BORLA has about 50 years of combined automotive acoustical experience in their R&D Department. In addition, both Alex Borla and Marian Juszak listen to and drive almost every system they build. Then, the final test: they have dozens of hardcore automotive enthusiasts employed at BORLA and they review most systems. Experience in this, like any technical industry, really counts. It is amazing how often a new engine design comes along, and they hit it right away. For example, when McLaren did the Mercedes SLR with the mufflers in the engine area, BORLA engineers produced a fantastic sounding product within a couple days. It isn't easy to improve on some of these cars. The SLR is around a million dollars, so you can be sure Dr. Z and his group didn't cut corners.
How does a muffler's sound and performance differ based on its location in the exhaust system?
Muffler design is the main factor. The chambered mufflers send the sound waves back and forth in the muffler so the muffler is very loud. For example, think of a '69 Camaro with the hot street muffler of the day. At the time, the driver didn't care if it was loud inside the car or out; he wanted people to hear those horses. Today, enthusiasts like to hear the CD player or carry on a conversation while still enjoying a muscle car. Hence the recent muffler relocation to the rear on most vehicles - an effort to keep resonance down inside the vehicles. Breaking down the sound, however you do it, will be quieter for the driver done as far away from them as possible. Effectively speaking: mufflers placed within about 18" of the header collector make the most power.
Do you seek a "brand" sound for each engine, or does one good design just happen to work?
BORLA delivers a sound unique to the vehicle. An Audi or BMW owner is going to have a different "ear" than a Mustang GT owner. A Jaguar is tuned differently than a Diesel Crew Cab ride. Will they all still find the "five points" (performance, sound, looks, warranty and cost)? Sure. BORLA just tailors the sound to fit the enthusiast who owns that car, not try to force them to like one, standard sound.
Will I need to re-program my ignition control computer?
No re-programing of your computer is necessary. You can expect the computer to adjust to the change over a period of approximately 300-400 miles of operation. After that time, the full benefits of the system will be realized. Even though ECU upgrades are not required with a BORLA exhaust systems, the added exhaust performance will aid the performance of an ECU upgrade.
Why does the use of an "X" pipe in dual exhaust make such a difference?
The firing order of a V8 has one cylinder in each bank that will fire within 90 degrees of crankshaft rotation of another cylinder in the same bank. This occurs twice during completion of the entire firing order. These two cylinders will be exhausting almost simultaneously into the same exhaust manifold system.
A good header helps separate these pulses until the collector is reached. If this is a full race car running "open exhaust", you will notice the collector dumps into a short open pipe at least 2.5 times the size of the header pipes or the header pipes dump direct without a collector. This is done to avoid the conflict of pressure caused by the timing of the 2 counter firing cylinders, which will create back pressure and degrade torque, horsepower and general performance, especially at higher RPM.
On a full exhaust system, after the header tubes dump into the collectors, the two close firing cylinders are fighting each other for space in the collector and exhaust pipe. The result is reflected pressure waves traveling back up the exhaust system, backpressure, lost power and poor economy.
At the same time two cylinders exhaust in one bank, there is no activity in the opposite bank. A crossover pipe allows some of the excess pressure to bleed over to the 'quiet side' of the exhaust system, resulting in some low and mid-range torque improvements. At high RPMs, however, in traditional exhaust systems, the gases cannot bleed across the H-pipe fast enough to help power significantly. Performance systems with the H pipe design, attempt to overcome this by using a shorter cross over pipe, which is also slightly larger in diameter than the main exhaust.
To overcome the power loss of "over loading" the H pipe design, Exhaust manufacturers came up with the X pipe design, which features a tangentially Siamese crossover junction to synchronize exhaust pulses. The X-pipe concept is to split the flow in the crossover junction, so the pressures on both banks will be equal and pulse-free after the crossover, regardless of the rpm. Volumetric efficiency and power are therefore improved at all engine speeds.
As far as sound goes, let's not forget that an exhaust note is the result of pressure pulses (i.e. the staccato belching of exhaust gases out of each exhaust valve put together via the collectors and any X/H pipe along the way). It's why long tubes can sound very different from short tube headers. So you'll have some pulses from one side filling in the vacant spots of the other side, and that will change the exhaust tone for sure.