Aftermarket turbocharging has become one of the most effective ways to transform a regular performance car into a high-horsepower machine without completely rebuilding the engine. A turbocharger works by forcing more air into the engine’s combustion chamber, allowing it to burn more fuel and produce significantly more power.
When properly tuned and supported with the right fuel system, cooling upgrades, and internal engine strength, a turbo kit can sometimes increase horsepower by 50 percent, 100 percent, or even more in extreme builds. This is why turbo kits are widely used in motorsports, street performance builds, drag racing, and even enthusiast daily drivers who want a major power boost.
Over the years, several manufacturers have developed turbo systems that are known for reliability, efficiency, and massive performance gains across different platforms, from Japanese sports cars to American muscle cars and European performance machines.
Brands like Garrett, BorgWarner, HKS, GReddy, Precision Turbo, Turbonetics, and others have built reputations for delivering high-quality forced induction systems that can dramatically change a car’s character. While the exact horsepower increase depends on the engine, tuning quality, fuel type, and supporting modifications, many of these kits are capable of effectively doubling horsepower in properly built setups.
In this article, we will explore 10 well-known aftermarket turbo kits and systems that have been widely used in performance builds around the world. Each section will explain how the kit works, what makes it popular, and why it has earned a reputation for delivering major horsepower gains.
Whether you are an automotive enthusiast, a tuner, or simply curious about how turbo systems unlock performance, this guide provides a detailed look into some of the most influential turbocharging solutions in the aftermarket industry today.
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1. Garrett Performance Turbo Systems (GT and G Series)
Garrett is one of the most recognized names in forced induction technology, known for producing OEM-level and aftermarket turbochargers used in everything from street cars to professional motorsport applications. Their GT and newer G Series turbochargers are widely used in universal turbo kits because they offer a strong balance between reliability, airflow efficiency, and high horsepower potential.
Garrett turbo systems are not always sold as complete vehicle-specific kits, but rather as modular components that tuners use to build custom setups. This flexibility allows builders to match turbo size to engine displacement and horsepower goals, making it possible to significantly increase output, often doubling stock power in the right configuration.
One of the biggest advantages of Garrett turbos is their advanced aerodynamics, which improve spool time while maintaining high top-end efficiency. This means drivers can experience reduced turbo lag while still achieving strong peak horsepower figures. Many modern performance builds use Garrett G30 or G35 units for this reason.
In real-world applications, Garrett turbo systems are used in platforms like Nissan 350Z, Toyota Supra builds, BMW N54 and N55 engines, and various V8 muscle cars. With proper tuning and supporting mods, these setups can reliably produce high boost levels and dramatically increase horsepower.
2. BorgWarner EFR Turbo Kits
BorgWarner’s EFR (Engineered For Racing) turbo series is designed for high-performance applications where responsiveness and efficiency are both critical. These turbos are widely praised for their integrated features, including built-in wastegates, boost control, and lightweight turbine wheels that improve spool characteristics.
EFR turbo kits are commonly used in custom performance builds rather than factory bolt-on systems. However, many aftermarket companies design vehicle-specific kits around EFR units, making them a popular choice for enthusiasts seeking major horsepower gains without sacrificing drivability.
One of the key strengths of BorgWarner EFR turbos is their ability to deliver strong mid-range torque while still supporting high horsepower numbers at the top end. This makes them ideal for both street performance and track use, where flexibility is important.
In terms of power potential, EFR turbos are capable of supporting builds that double factory horsepower in many four-cylinder and six-cylinder applications. This depends heavily on engine strength and supporting modifications such as fuel injectors and intercooling systems.
Because of their advanced design and efficiency, BorgWarner EFR turbo systems are often considered a premium choice for enthusiasts who want a modern, responsive, and highly capable turbo upgrade.
3. HKS GT Turbo Kits (GTII and GTIII Series)
HKS is a legendary Japanese tuning company known for its high-performance aftermarket parts, and its GT turbo kits have been widely used in JDM performance culture for decades. The GTII and GTIII turbo series are designed for high boost applications and are commonly found in Toyota, Nissan, and Subaru performance builds.
HKS turbo kits are often vehicle specific, meaning they come with all necessary components for installation, including manifolds, piping, intercoolers in some cases, and supporting hardware. This makes them popular among tuners who want a reliable bolt-on upgrade with proven performance results.
The GTIII series, in particular, is known for its ability to support significant horsepower increases while maintaining durability under high boost conditions. These kits are often used in drag racing and circuit racing applications where consistent power delivery is essential.
Many tuned vehicles using HKS GT turbo kits are capable of producing well over twice their original factory horsepower when properly built. However, this requires upgraded fuel systems and reinforced engine internals in most cases.
HKS continues to be respected in the tuning community because of its engineering precision and long history in competitive motorsport environments.
4. GReddy Turbo Kits (T518Z, T78, T88 Series)
GReddy is another major Japanese aftermarket brand known for producing complete turbo kits for a wide range of performance vehicles. Their turbo systems, including the T518Z, T78, and T88 setups, are designed for high-horsepower applications and are commonly used in street and drag racing builds.
GReddy kits are popular because they are often designed as bolt-on solutions for specific engines, making installation more straightforward compared to fully custom turbo setups. They typically include manifolds, piping, intercoolers, and oil lines.
The T78 and T88 turbo systems are especially well known for their ability to support very high horsepower levels, often used in high-performance Nissan RB26DETT engines, Toyota Supra 2JZ builds, and other iconic JDM platforms.
With proper tuning, GReddy turbo kits are frequently capable of pushing engines to double or more their stock horsepower, especially in reinforced engines designed for high boost operation.
GReddy’s reputation comes from its long involvement in tuning culture and its consistent ability to deliver reliable, high-output turbo systems.
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5. Precision Turbo & Engine Kits
Precision Turbo & Engine is a leading American manufacturer specializing in high-performance turbochargers for racing and street performance applications. Their turbo kits are widely used in drag racing, roll racing, and high-horsepower street builds.
Precision turbo systems are known for their strong airflow capacity and ability to support extremely high boost levels. Many of their turbochargers are capable of supporting four-digit horsepower builds when properly configured.
These kits are often used in custom setups rather than direct bolt-on applications, but many aftermarket companies design vehicle-specific kits using Precision turbo units. This flexibility makes them a favorite among professional tuners.
In terms of performance potential, Precision Turbo systems are commonly used in builds that significantly exceed factory horsepower, often doubling or tripling output depending on engine strength.
Their reputation in motorsport is built on consistency, durability, and the ability to perform under extreme conditions.
6. Turbonetics Turbo Systems
Turbonetics is a long-established turbocharger manufacturer known for producing performance-oriented turbo kits for street and racing applications. Their systems are widely used in domestic American platforms such as Ford Mustang, Chevrolet Camaro, and Dodge performance vehicles.
Turbonetics turbo kits are designed to provide strong mid-range power and high top-end horsepower, making them suitable for both street driving and drag strip use. Many kits include intercoolers, manifolds, and fuel system recommendations.
One of the strengths of Turbonetics systems is their focus on balanced performance, offering both spool efficiency and high horsepower capability. This makes them versatile across different driving styles.
In properly built engines, Turbonetics turbo kits are capable of doubling factory horsepower output, especially in V8 applications with strong internal components.
The brand remains popular among American performance enthusiasts due to its reliability and availability of vehicle-specific kits.
7. Hellion Twin Turbo Kits (Ford Mustang Focus)
Hellion is best known for its twin turbo kits designed specifically for Ford Mustang platforms, particularly Coyote V8 engines. These kits are engineered to transform naturally aspirated muscle cars into high-horsepower turbocharged machines.
Hellion systems are typically complete bolt-on kits that include twin turbochargers, piping, intercoolers, wastegates, and fuel system recommendations. They are designed for relatively straightforward installation compared to fully custom setups.
The twin turbo configuration allows for quick spool and strong top-end power, making these kits highly effective for both street performance and drag racing applications.
Many Mustang builds using Hellion kits are capable of producing double or more the factory horsepower, especially when paired with upgraded fuel systems and tuning.
Hellion has built a strong reputation in the muscle car community for delivering reliable and extremely powerful turbo solutions.
8. AVO Turbo Kits (Subaru WRX and STI)
AVO Turboworld specializes in turbo kits for Subaru platforms, particularly the WRX and STI models. These kits are designed to enhance the performance of Subaru’s boxer engines while maintaining reliability.
AVO turbo kits are often bolt-on solutions that include turbochargers, intercoolers, piping, and supporting hardware tailored for Subaru engines. They are popular among enthusiasts who want a balanced upgrade without extreme modification.
One of the advantages of AVO systems is improved spool response combined with strong mid-range torque, which complements Subaru’s rally-inspired driving characteristics.
When properly tuned and supported with upgraded fuel systems, AVO turbo kits can significantly increase horsepower, often approaching or exceeding double stock output in built engines.
AVO remains a respected name in the Subaru tuning community due to its focus on reliability and drivability.
9. APS Turbo Kits (Subaru Legacy and WRX Platforms)
APS (Air Power Systems) was an Australian company known for producing high-quality turbo kits for Subaru and other performance vehicles. Their kits were especially popular in early Subaru tuning communities.
APS turbo systems were designed as complete bolt-on upgrades, often including turbochargers, intercoolers, intake systems, and fuel system components. They were engineered for strong performance gains with relatively straightforward installation.
These kits became known for delivering substantial horsepower increases, often transforming stock Subaru engines into significantly more powerful machines capable of handling much higher boost levels.
In many tuned setups, APS turbo kits were capable of doubling horsepower when paired with proper engine reinforcement and tuning.
Although APS is no longer as prominent in the market today, its legacy remains strong in the Subaru performance community.
10. AMS Performance Turbo Systems (Nissan GT-R Focus)
AMS Performance is widely known for its extreme Nissan GT-R builds, particularly the Alpha series turbo upgrades for the VR38DETT engine. These systems are designed for very high horsepower applications.
AMS turbo systems are highly customized and often include upgraded turbochargers, fuel systems, intercoolers, and engine reinforcement components. They are engineered for maximum performance in both street and drag racing environments.
One of the standout features of AMS builds is their ability to push GT-R platforms far beyond factory specifications, often reaching extremely high horsepower levels that far exceed stock output.
In properly built configurations, AMS turbo systems can easily double, triple, or even surpass that level of power increase depending on the setup.
AMS Performance is widely respected in the global tuning community for pushing the limits of what the Nissan GT-R platform can achieve.
