This Borg Warner variable geometry turbine turbo uses vanes with two axles. It is called a double axle vane. So an axle which the vane pivots on is used on both the top and bottom sides of the vane for strength. This is common in heavy duty applications where the vanes can be closed for engine braking. If you look over to the left at the compressor wheel, Borg Warner uses this particular seal plate design across many of their turbos. Even their EFRs use this seal plate design. It might even be the same part number as this turbo.
The engine must be up against the rear firewall of the engine bay judging by the design of the downpipe coming off the DPF. It’s not exactly what you would call optimized for power, but hey, I’m sure the engineers did the best they could given the space they had to work with. Sometimes, you just gotta make do with the hand you’re dealt.
This is GMs new 2.8L turbo diesel to compete with the Dodge Ram with the 3.0L diesel which has been kicking ass. The exhaust flow on this engine package is much more free-flowing coming out of the DPF.
This VNT turbo (or VGT depending on the company), has a single axle vane. The vane pivots only on one axle which makes it weaker versus a double axle vane, but the single axle is also cheaper and allows for the turbo being more compact. So, it’s often found in diesel passenger cars.