Maximize performance & increase turbo life
Garrett’s Two-Stage serial turbo for diesel multiplies the benefits of turbocharging, improves transient performance, optimizes fuel efficiency and more.
Two-Stage Serial Turbochargers for Diesel Engines
Key Features
Using our Two-Stage serial turbo for diesel applications, compressors operate at peak efficiency by dividing their workload between two turbos:
- Fresh air is drawn into the first-stage compressor
- The pressure is increased by 2 to 2.5 times
- This pressurized air is sent to the second-stage compressor
- The pressure is increased another 2 to 2.5 times
Lower pressure ratios at each stage result in slower rotating speeds. This improves the reliability of bearing systems, compressor wheels, and turbine wheels. In addition, Two-Stage serial turbos for diesel regulate gas flow between the turbos using bypass valves. These valves change modes according to speed, optimizing gas transfer between the small high-pressure turbo and the large low-pressure turbo:
- Below 1500 rpm: Both compressor and bypass valves remain closed, increasing boost pressure and torque.
- From 1500 rpm to 2800 rpm: Bypass valves begin to open to channel exhaust gas between turbos.
- Beyond 2800 rpm: Both compressor and bypass valves remain fully open, regulating gas flow only to the larger turbo.

Engine Range
Garrett’s Two-Stage serial turbo for diesel compounds the benefits of turbocharging by using two turbos in a series arrangement. This helps improve transient performance, offers better low-speed torque and optimizes fuel efficiency in passenger and commercial vehicle applications. Auto manufacturers can use this technology to either downsize engines or increase performance. Our Two-Stage serial turbo for diesel can be used with a variety of engine sizes, from small single-liter vehicles to massive 64L mining equipment. However, they are most commonly used in engines ranging in size from 1.6L to 3L.

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