DualBoost Turbocharger

6.7L Power Stroke DualBoost SST Turbo Information

2011 through 2014 model year 6.7L Power Stroke diesel engines featured Honeywell's VNT DualBoost turbocharger. The single sequential turbocharger, or SST, is a single turbocharger design containing two compressors. This attribute allows the DualBoost turbocharger to provide the performance characteristics of a sequential twin turbo system while occupying much less space. A single turbine powers both compressors, the speed of which is controlled by both a conventional wastegate and variable vane technology.

The DualBoost single sequential turbocharger is a "2-in-1" design - a single turbine powering a pair of compressors. A unique feature of the DualBoost turbo is that it is a wastgated variable geometry turbocharger. Traditionally, variable vane turbochargers do not require a wastegate system, but rather prevent turbocharger over-speeding by opening vanes in the turbine housing. The DualBoost, by contrast, utilizes variable vane technology to obtain favorable spooling characteristics and a wastegate to eliminate the risk of over-speeding.

6.7L Power Stroke SST DualBoost turbocharger

Cutaway view of the single sequential DualBoost turbocharger found on the 2011 - 2014 6.7L Power Stroke Diesel

The turbocharger's efficiency is further improved as a result of the unique intake and exhaust manifold arrangement on the 6.7L Power Stroke. Unlike a traditional "V" engine, the 6.7L Power Stroke's exhaust manifolds exit into the valley of the engine where the turbocharger is mounted. The result is reduced pumping losses, minimal energy is lost as gases travel from the exhaust manifold to the turbine housing, and less exhaust plumbing is required.

On the intake side, the intake manifolds and ports are located on the outer sides of the engine block. After being pressurized via the turbocharger, air travels through a air-to-water charge air cooler (CAC). The 6.7L Power Stroke features two separate cooling systems, one circuit for the engine (high temp system) and another circuit for the CAC, transmission cooler, EGR cooler, and fuel cooler.