The Cummins ISX engine is a powerhouse for heavy-duty trucks, known for its durability, torque, and fuel efficiency. However, to keep it running at peak performance, the turbocharger plays a critical role. Whether you’re replacing a worn-out OEM unit or upgrading to a high-performance model, choosing the right turbocharger can dramatically improve horsepower, boost response, and overall engine life.
This guide explores the 10 best turbochargers for Cummins ISX engines, complete with technical specs, installation tips, and performance insights to help you make an informed decision.
Table of Contents
- BorgWarner S300SX-E
- Holset HX35W
- Garrett GT3788VA
- Holset HE351CW
- BorgWarner S400SX-E
- Cummins OEM Turbocharger
- Holset HX55
- BorgWarner EFR Turbo Series
- Holset HE400VG
- Precision Turbo PT Series
- Comparison Table
1. BorgWarner S300SX-E
The BorgWarner S300SX-E is a favorite among performance enthusiasts who want faster spool and reliable boost pressure. Its advanced aerodynamics and ball-bearing design deliver consistent airflow and efficiency.
Technical Specs:
- Max Boost: 35 psi
- Flow Rate: 74 lb/min
- Supported Horsepower: 600–800 HP
- Compressor Wheel: 67mm
Installation Tips:
- Compatible with most ISX engines (2007+)
- Requires tuning for optimal performance
- Moderate installation difficulty
Performance:
The S300SX-E offers excellent throttle response, noticeable improvements in acceleration, and better fuel efficiency. It is ideal for ISX owners seeking balanced upgrades without excessive lag.
2. Holset HX35W
The Holset HX35W is one of the most reliable OEM-style turbos for Cummins ISX engines. Known for its durability, it delivers excellent low-end torque, making it perfect for long-haul trucks.
Technical Specs:
- Max Boost: 30 psi
- Flow Rate: 65 lb/min
- Supported Horsepower: 450–600 HP
- Turbine Wheel: 55mm
Installation Tips:
Direct OEM fit, no modifications required
Simple bolt-on installation
Recommended for fleets and daily drivers
Performance:
Expect smoother torque delivery and long service life. While it’s not designed for extreme horsepower builds, its reliability makes it a trusted choice for commercial vehicles.
3. Garrett GT3788VA
The Garrett GT3788VA is a variable geometry turbocharger (VGT) designed to optimize boost at all RPM ranges. Its VGT mechanism allows for smoother acceleration and reduced lag.
Technical Specs:
- Max Boost: 40 psi
- Flow Rate: 80 lb/min
- Supported Horsepower: 650–850 HP
- Turbine: Variable Geometry
Installation Tips:
Requires ECU tuning to maximize benefits
Works best with 2007+ ISX engines
Medium installation difficulty
Performance:
This turbocharger delivers excellent mid-range power, making it perfect for fleet vehicles that require strong highway performance and fuel efficiency.
4. Holset HE351CW
Compact yet efficient, the Holset HE351CW is designed for quick spool and stable boost. It is favored for medium-duty Cummins ISX applications.
Technical Specs:
- Max Boost: 32 psi
- Flow Rate: 70 lb/min
- Supported Horsepower: 500–650 HP
- Compressor Wheel: 60mm
Installation Tips:
Direct fit for specific ISX models
Requires minor calibration adjustments
Easy to moderate installation
Performance:
With quick spool characteristics, this turbo delivers steady boost across RPMs. It’s ideal for drivers needing balanced performance in daily operations.
5. BorgWarner S400SX-E
Designed for high-horsepower applications, the S400SX-E is one of the most powerful turbos for Cummins ISX engines.
Technical Specs:
- Max Boost: 45+ psi
- Flow Rate: 95 lb/min
- Supported Horsepower: 850–1,200 HP
- Compressor Wheel: 76mm
Installation Tips:
- Requires performance tuning and modifications
- Best installed by professionals
- Not recommended for stock ISX engines
Performance:
This turbo supports maximum power builds, delivering aggressive acceleration and high top-end performance. Best for racing or custom heavy-duty applications.
6. Cummins OEM Turbocharger
The safest option for reliability and compatibility, OEM Cummins turbos are built specifically for ISX engines.
Technical Specs:
- Boost: Factory calibrated
- Supported Horsepower: 450–600 HP
- Perfect OEM fit
- Installation Tips:
- Direct fit with zero modifications
Plug-and-play reliability
Best for fleets and long-haul drivers
Performance:
While it won’t drastically increase horsepower, OEM turbos provide unmatched reliability, making them ideal for fleets prioritizing uptime.
7. Holset HX55
Built for extreme duty, the Holset HX55 handles long-haul and heavy-load applications.
Technical Specs:
- Max Boost: 38 psi
- Flow Rate: 85 lb/min
- Supported Horsepower: 700–900 HP
- Turbine Wheel: 70mm
Installation Tips:
- Requires reinforced components for high boost
- Moderate to difficult installation
- Ideal for freight and construction trucks
Performance:
Strong high-RPM performance and robust construction make it perfect for trucks pulling heavy loads across long distances.
8. BorgWarner EFR Turbo Series
The EFR series represents BorgWarner’s most advanced turbo technology, featuring lightweight titanium wheels and ceramic bearings.
Technical Specs:
- Max Boost: 35–40 psi
- Flow Rate: 75 lb/min
- Supported Horsepower: 600–800 HP
- Ultra-light compressor design
Installation Tips:
Requires custom tuning
Works best with performance ISX builds
Moderate installation complexity
Performance:
This turbo provides lightning-fast spool, improved efficiency, and excellent power delivery. Great for performance enthusiasts who want cutting-edge design.
9. Holset HE400VG
The HE400VG is a variable geometry turbo optimized for fuel efficiency and reliability.
Technical Specs:
- Max Boost: 38 psi
- Flow Rate: 78 lb/min
- Supported Horsepower: 600–800 HP
- VGT design for flexible boost
Installation Tips:
- Requires ECU tuning
- Compatible with newer ISX models
- Moderate installation difficulty
Performance:
Excellent fuel economy and smooth torque delivery make it ideal for long-haul drivers who need dependable efficiency.
10. Precision Turbo PT Series
Precision Turbo’s PT series is built for high-performance and customizable boost options.
Technical Specs:
- Max Boost: 45+ psi
- Flow Rate: 90+ lb/min
- Supported Horsepower: 900–1,200 HP
- Custom trim options available
Installation Tips:
Requires advanced tuning
Ideal for racing and custom performance builds
High installation complexity
Performance:
Designed for tuners and performance enthusiasts, this turbo offers exceptional horsepower potential and flexibility for aggressive builds.
11. Comparison Table
| Turbocharger | Boost (psi) | HP Support | Best For |
|---|---|---|---|
| BorgWarner S300SX-E | 35 | 600–800 HP | Balanced performance & reliability |
| Holset HX35W | 30 | 450–600 HP | Daily driving & fleets |
| Garrett GT3788VA | 40 | 650–850 HP | Highway & fleet efficiency |
| Holset HE351CW | 32 | 500–650 HP | Medium-duty applications |
| BorgWarner S400SX-E | 45+ | 850–1,200 HP | High horsepower builds |
| Cummins OEM | Factory | 450–600 HP | OEM reliability |
| Holset HX55 | 38 | 700–900 HP | Heavy hauling |
| BorgWarner EFR Series | 35–40 | 600–800 HP | Modern performance upgrades |
| Holset HE400VG | 38 | 600–800 HP | Fuel efficiency & long-haul use |
| Precision Turbo PT | 45+ | 900–1,200 HP | Performance tuning & racing |
Conclusion
Selecting the right turbocharger for your Cummins ISX engine depends on your goals. If you value reliability and OEM fit, the Holset HX35W or Cummins OEM turbo are safe bets. For high-performance applications, the BorgWarner S400SX-E or Precision PT series deliver unmatched horsepower. Fleet operators looking for fuel efficiency should consider the Garrett GT3788VA or Holset HE400VG.
