When it comes to forced induction, few names carry the weight of Garrett Motion. The company's GT Series turbochargers have powered everything from weekend track cars to championship-winning dragsters, earning a reputation for reliability, efficiency, and predictable power delivery. Whether you're building a mild street machine or a full-race setup, the right GT Series turbo can make the difference between a car that feels fast and one that dominates. In this guide, we break down the top 10 Garrett GT Series turbochargers for maximum power gains, covering their specs, ideal applications, and what makes each one unique.

Top 10 Garrett GT Series Turbochargers

1. Garrett GT28RS (Disco Potato)

The GT28RS, better known as the "Disco Potato," is a legend in the tuning community for its combination of rapid spool and surprising top-end flow. Designed with a 60mm compressor wheel and a 56mm turbine, this turbo reaches full boost as low as 3,500 rpm on a 1.8–2.0L engine, making it an excellent choice for four-cylinder applications like the SR20DET, 4G63, or Toyota 3S-GTE. It supports up to 400 horsepower with proper supporting mods. Because of its small frame, it fits many stock manifold locations without major fabrication. Tuners often pair it with a ported factory manifold and a quality intercooler to maximize gains.

  • Compressor Size: 60mm
  • Max Boost: 20–22 PSI
  • Horsepower Range: 250–400 hp
  • Ideal For: Street-driven four-cylinders, autocross, daily drivers

2. Garrett GT30R

The GT30R turbocharger is a versatile workhorse that bridges the gap between quick spool and high-rpm power. With a 76mm compressor wheel and a 68mm turbine, it offers excellent throttle response on both four- and six-cylinder engines. It is a popular upgrade for inline-six platforms (such as the Toyota 2JZ-GTE and Nissan RB25) and larger four-cylinders. The GT30R can produce up to 550 horsepower when paired with the right tune and fuel system. Its dual-ball-bearing center housing reduces friction and improves transient response, making it a favorite for road racing and time attack builds.

  • Compressor Size: 76mm
  • Max Boost: 30 PSI
  • Horsepower Range: 400–550 hp
  • Ideal For: Six-cylinder street/track cars, high-output four-cylinders

3. Garrett GT35R

If you're targeting 600–800 horsepower, the GT35R is the benchmark. Its 82mm compressor wheel combined with a 76mm turbine moves enough air to support serious power on 2.5L and larger engines. The GT35R delivers a noticeable surge in boost around 4,000 rpm, then pulls hard to redline. It's a common choice for LS swaps, RB26 builds, and 2JZ-GTE engines running high boost. The T4 turbine housing options allow for both twin-scroll and single-scroll configurations, giving tuners flexibility in spool characteristics. Expect to upgrade your fuel system and charge piping to get the most out of this turbo.

  • Compressor Size: 82mm
  • Max Boost: 35 PSI
  • Horsepower Range: 600–850 hp
  • Ideal For: High-horsepower street/strip cars, big six- and eight-cylinder engines

4. Garrett GT37

The GT37 turbocharger steps into the realm of serious performance with an 88mm compressor wheel and a 92mm turbine. It is designed for engines that need substantial airflow, such as large V8s or six-cylinders with aggressive cams. The GT37 shines in applications where the power goal exceeds 800 hp. It features a reinforced bearing system to handle sustained high-rpm operation, making it suitable for mile racing or track days. A properly matched wastegate and blow-off valve are critical to manage the boost levels, as the GT37 can easily climb past 40 PSI.

  • Compressor Size: 88mm
  • Max Boost: 40 PSI
  • Horsepower Range: 800–1,000 hp
  • Ideal For: Big V8s, competition drag cars, endurance engines

5. Garrett GT40

When extreme power levels are the goal, the GT40 turbocharger delivers. With a 94mm compressor wheel and a 100mm turbine, this unit is built for engines that can handle massive airflow—think high-boost big-block V8s or fully built inline-sixes. The GT40 supports up to 1,200 horsepower at boost levels around 45 PSI. Its large turbine housing provides excellent top-end pull, but expect a trade-off in spool time. This turbo is best paired with a high-flow intake manifold and a custom fabricated exhaust manifold to keep the gas velocities up. Cylinder head porting and oversized injectors are typically mandatory.

  • Compressor Size: 94mm
  • Max Boost: 45 PSI
  • Horsepower Range: 1,000–1,200 hp
  • Ideal For: Extreme street/strip cars, land speed racing, competition use

6. Garrett GT42

For serious racers, the GT42 turbocharger is a massive step-up. A 102mm compressor wheel feeds air into engines that need to move enormous volumes of exhaust gas. This turbo is often found on V8 drag cars making over 1,500 horsepower. It requires a substantial wastegate setup to regulate boost, as the GT42 can generate boost levels up to 50 PSI. Because of its size and weight, the GT42 is not practical for daily driving or tight engine bays, but in a dedicated race car it provides unmatched top-end flow. Consider using a billet wheel upgrade for even faster spool within the same frame.

  • Compressor Size: 102mm
  • Max Boost: 50 PSI
  • Horsepower Range: 1,400–1,800+ hp
  • Ideal For: Full race engines, top-fuel dragsters, endurance competition

7. Garrett GT45

The GT45 turbocharger is another giant in the GT lineup, boasting a 105mm compressor wheel and a 110mm turbine. It is a staple in the drag racing and high-horsepower street scene. The GT45 can handle boost pressures in excess of 55 PSI, pushing power well beyond 2,000 horsepower. Its design prioritizes reliability under extreme thermal and mechanical stress. Because of the sheer volume of airflow, a proper intercooling system and high-octane fuel are non-negotiable. Many builders pair the GT45 with a methanol injection kit to control intake temperatures.

  • Compressor Size: 105mm
  • Max Boost: 55 PSI
  • Horsepower Range: 1,800–2,200+ hp
  • Ideal For: Dragsters, pro mod cars, ultra-high-output builds

8. Garrett GT47

When you need to push the absolute limit, the GT47 turbocharger delivers. With a 107mm compressor wheel and a 114mm turbine, it is one of the largest production turbos in the Garrett GT line. Designed for the most demanding applications, the GT47 supports up to 2,500 horsepower at boost levels around 60 PSI. It is not uncommon to see this turbo on large-displacement V8s with twin-turbo setups. The sheer size requires custom headers, dump tubes, and a robust wastegate system. Engine builders must pay strict attention to oiling and cooling, as the GT47 generates immense heat.

  • Compressor Size: 107mm
  • Max Boost: 60 PSI
  • Horsepower Range: 2,200–2,500+ hp
  • Ideal For: Top-tier competition engines, land speed record runs

9. Garrett GT50

The GT50 turbocharger is built for maximum performance and is a favorite in the professional racing community. A 110mm compressor wheel and 118mm turbine allow this turbo to move airflow volumes that would choke smaller units. It can handle up to 65 PSI of boost, translating into horsepower figures that tower over 3,000 horsepower in the right engine package. The GT50 uses a fully machined compressor housing and a race-optimized bearing system to ensure longevity at extreme rotational speeds. It is typically reserved for top-fuel cars, offshore racing boats, and large-scale dyno competitions.

  • Compressor Size: 110mm
  • Max Boost: 65 PSI
  • Horsepower Range: 2,800–3,500+ hp
  • Ideal For: Top-fuel dragsters, unlimited competition engines

10. Garrett GT55

At the peak of the Garrett GT Series sits the GT55 turbocharger—a true engineering marvel. With a 115mm compressor wheel and a 122mm turbine, the GT55 is capable of supporting over 4,000 horsepower when properly fed by a massive engine. Its maximum boost rating of 70 PSI underscores its purpose: absolute, uncompromising power. The GT55 is not a bolt-on; it requires a fully custom exhaust system, specialized oil scavenge pumps, and a reinforced engine block. It represents the ultimate choice for teams competing in unlimited classes where the rules do not constrain turbocharger size.

  • Compressor Size: 115mm
  • Max Boost: 70 PSI
  • Horsepower Range: 3,500–4,000+ hp
  • Ideal For: Unlimited drag racing, aerospace engine test cells, large diesel engines

How to Choose the Right Garrett GT Turbocharger

Selecting the correct turbocharger from this list depends on several factors: engine displacement, intended use (street vs. race), power goals, and budget. Smaller engines (1.5–2.5L) benefit from the GT28RS or GT30R for quick spooling power, while large V8s chasing 1,000+ hp will look toward the GT40 and above. Always consider the flow rate of your cylinder head and the quality of your fuel. A turbo that is too large will suffer from lag and drivability issues; one that is too small will choke the engine at high RPM. Use Garrett's online turbo selection tool (available at Garrett Motion) to input your engine specs and target horsepower.

Tuning and Installation Considerations

Every turbocharger on this list demands proper tuning. A standalone engine management system (such as a Motec, Haltech, or AEM) is essential to map the fuel and ignition tables for the increased airflow. Additionally, you must upgrade the fuel system—injectors, pump, and lines—to match the turbo's potential. The GT42, GT45, GT47, GT50, and GT55 require heavy-duty wastegates to regulate boost spikes and prevent overspeed. Never run these massive turbos without a boost controller and proper pressure relief. Oil feed and drain lines should be sized according to the turbo's bearing type (journal or ball bearing). For more detailed installation guides, refer to the Garrett Knowledge Center.

Conclusion

The Garrett GT Series offers a turbocharger for virtually every power level, from 250 horsepower street cars to 4,000+ horsepower competition engines. Choosing the right unit requires honest assessment of your engine's capabilities and your performance goals. The GT35R remains a sweet spot for many high-performance street cars, while the GT55 is the apex of forced induction engineering. No matter which you choose, you can count on Garrett's heritage of quality and aftermarket support. Pair your turbo with correct supporting modifications, a professional tune, and you will unlock the maximum power gains your engine can deliver.

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