How Much HP Does a Borla Exhaust Add? Real Data & Expectations

You just dropped money on a new Borla exhaust is a high-performance aftermarket exhaust system known for its aggressive sound and proven power gains through optimized flow dynamics. Also recognized as Borla Performance, it has been a staple in the automotive tuning scene since 1966. system. You installed it because you wanted that deeper rumble and maybe a bit more pep off the line. But here is the question keeping you up at night: did it actually add horsepower, or did you just buy a louder pipe?

The short answer is yes, but not in the way magazine ads might make you think. A standalone Borla exhaust typically adds between 5 to 15 wheel horsepower (WHP) on naturally aspirated vehicles. For turbocharged engines, those numbers can jump significantly higher-sometimes 20 to 30 WHP or more-if paired with a tune. However, expecting a 50-horsepower jump from an exhaust swap alone is a fantasy that leads to disappointment.

Why Exhausts Add Horsepower: The Science of Flow

To understand why your car makes more power with a Borla system, you have to look at how an engine breathes. An internal combustion engine works by sucking in air, mixing it with fuel, igniting it, and then pushing the resulting gases out. This process happens thousands of times per minute. If the exit door for those gases is narrow or restrictive, the engine has to work harder to push them out. This creates backpressure.

Backpressure is the resistance to exhaust gas flow caused by restrictions in the exhaust system, which reduces engine efficiency and power output. Think of it like trying to breathe through a straw. If you hold one end partially closed, you struggle to exhale fully. Because you couldn't get all the old air out, there is less room for fresh air to come in. Your engine suffers from the same issue. When the exhaust gases cannot escape quickly, they linger in the cylinders, preventing the next cycle of fresh air-fuel mixture from entering efficiently.

Borla systems address this by using larger diameter pipes, smoother bends, and high-flow catalytic converters or mufflers. By reducing restriction, the engine can expel exhaust gases more freely. This allows the pistons to complete their stroke with less effort, meaning more energy is transferred to the wheels rather than being wasted fighting against backpressure. This improvement in volumetric efficiency translates directly to measurable horsepower gains.

Real-World Horsepower Gains by Vehicle Type

Not every car reacts the same way to an exhaust upgrade. The amount of horsepower you gain depends heavily on your engine's design, displacement, and whether it uses forced induction. Here is what you can realistically expect based on dyno data from various platforms.

For example, if you drive a Ford Mustang GT with a 5.0L V8, a Borla ATAK cat-back system might give you around 8 to 12 WHP. It won't turn your Mustang into a supercar, but it will make the power feel more accessible. On the other hand, if you own a Subaru WRX or a BMW M3 with a turbocharger, the gains are often more pronounced. Turbos rely on exhaust gas velocity to spin the turbine. A freer-flowing exhaust helps the turbo spin up faster (reducing lag) and prevents pressure buildup at high RPMs, allowing the engine to produce peak power more consistently.

Atak vs. Xtreme vs. Touring: Which System Gives More Power?

Borla offers different lines tailored to specific needs, and these differences matter when chasing horsepower. The three main categories are Atak, Xtreme, and Touring.

Borla ATAK is Borla's highest-performance exhaust line featuring aggressive styling, maximum flow capabilities, and the loudest sound profile among their consumer products. The ATAK series is designed for enthusiasts who want maximum performance and volume. These systems often feature larger diameter piping (typically 3 inches) and less restrictive muffler designs. Because they prioritize flow above all else, ATAK systems generally yield the highest horsepower gains within the Borla lineup. However, the trade-off is noise. These systems are loud, especially under acceleration, and may cause drone at highway speeds depending on the vehicle.

Borla Xtreme is a mid-range performance exhaust offering a balance between power gains and manageable sound levels, suitable for daily drivers. The Xtreme line sits in the middle. It provides solid flow improvements over stock systems, usually resulting in comparable horsepower gains to the ATAK (within 1-2 WHP difference), but with a slightly tamed sound. It’s a good choice if you want performance without annoying your neighbors or passengers.

Borla Touring is a mild performance exhaust focused on subtle sound enhancement and modest flow improvements, ideal for conservative upgrades. The Touring series is the most conservative option. It focuses on a deep, refined tone rather than raw aggression. While it still improves flow compared to the restrictive factory exhaust, the horsepower gains are minimal-often just 2 to 5 WHP. You choose Touring for style and a slight performance bump, not for track-day numbers.

Does a Tune Unlock More Horsepower?

If you are serious about maximizing the potential of your Borla exhaust, you need to talk about software. Your car's engine control unit (ECU) is programmed by the manufacturer to work with the stock exhaust system. The ECU expects certain levels of backpressure and oxygen sensor readings. When you install a high-flow exhaust, you change those variables.

Without a tune, the ECU might interpret the increased airflow as a lean condition (too much air, not enough fuel). To protect the engine, it may adjust fuel delivery conservatively, limiting the power gains you could otherwise achieve. This is where a custom tune or a pre-made flash comes in. A tune recalibrates the ECU to recognize the new exhaust flow characteristics. It can optimize ignition timing and fuel maps to take full advantage of the reduced backpressure.

In many cases, especially with turbocharged vehicles, a tune combined with a Borla exhaust can double or triple the horsepower gains compared to the exhaust alone. For instance, a turbo BMW might see 10 WHP from the exhaust alone, but 30+ WHP when paired with a proper Stage 1 tune. Always consult with a reputable tuner before modifying your software to ensure reliability and avoid voiding warranties unnecessarily.

Other Benefits Beyond Horsepower

Horsepower isn't the only metric that matters. While the dyno sheet shows a number, the real-world driving experience often changes in subtler ways. One significant benefit is throttle response. With less restriction in the exhaust path, the engine feels more eager to rev. You notice this immediately when accelerating from a stoplight or merging onto a highway. The hesitation or "flat spot" some cars experience in the mid-range often disappears.

Weight reduction is another factor. Factory exhaust systems are built to meet strict noise and emissions regulations, which often means heavy, bulky components. Aftermarket systems like Borla use lighter materials and more compact designs. Shedding 15 to 30 pounds from the underside of your car improves handling, braking, and acceleration. It’s not a huge amount, but in performance driving, every pound counts.

Sound quality is subjective, but it’s a major reason people buy Borla. The acoustic engineering in these systems ensures a pleasant exhaust note that enhances the driving experience. Whether you prefer the growl of a V8 or the bark of a turbo four-cylinder, Borla tunes their mufflers to eliminate harsh drones while maintaining character.

Pitfalls to Avoid When Chasing HP

Before you spend hundreds or thousands of dollars on an exhaust upgrade, keep these realities in mind. First, diminishing returns apply. If your car already has a high-performance exhaust, adding another component yields negligible gains. Second, fitment issues can arise. Ensure the Borla system is specifically designed for your exact year, make, model, and trim. Even small variations in subframes or hangers can prevent installation.

Also, consider local noise ordinances. In places like Bristol, England, or many US cities, excessively loud exhausts can result in fines or failed MOT/emissions tests. While Borla systems are legal in most states when equipped with catalytic converters, check your local laws. Finally, remember that horsepower at the crankshaft is different from horsepower at the wheels. Dyno measurements vary, so compare apples to apples when looking at performance claims.