Once again, armed with photographs from the Saab TurboX Media Drive, I’m coming to you via the internet with information that you must, at all costs, absorb and hold dear because it’s going to be on the final exam.
Today’s topic: the GM 2.8 liter V6 in turbocharged form as in the upcoming Saab TurboX.
Oy, this is one smooth engine. After all, it’s won awards from people who really know a thing or two about engines, so you expect some refinement. This engine, as I’ve said before, has power and torque available from the minute that you stomp on the gas pedal. So, you really want to know how that power is made so quickly and smoothly, don’t you? Of course you do!
Well, here’s the secret: it has six cylinders.
And here’s the other secret: the turbocharger has two scrolls.
Now, I’m not advocating a wholesale change, and I’m not saying that everyone needs a 2.8 liter turbocharged V6, but I am saying that it’s nice to have in your product line because some people, myself included, will want the performance that it offers.
While at the Saab TurboX Media Drive, I studied the display V6 for a few minutes. After orienting myself and studying the airflow and the layout, the first thing that struck me was the additional piping and routing required to make a V arrangement work. On the four-cylinder Saabs, everything is easily routed from the same side of the inline bank of cylinders, while the V6 has to route exhaust to and inlet air from a single point on one side of the engine: the turbocharger. The well-sculpted inlets of the Saab V6 are a testament to both design and manufacturing prowess, but what a tangle it appears to be.
While we’re on the subject of metals, take a good look at the engine block and the cylinder heads. Casting technology has come a long way in just the past ten or twenty years. The detail and specialized shaping of each component is truly amazing and most certainly adds efficiency and performance.
The two-scroll turbocharger by Mitsubishi enhances the driver experience by allowing a workable variable inlet arrangment that gets the turbocharger impeller spinning at operating speeds with even a small change in exhaust flow. That is, turbo “lag” is greatly reduced. I can tell you first-hand that it works. With thirty years of turbocharging experience, Saab certainly made good choices with this one.
Not only is it easy to see the air and exhaust routing with this cutaway, it’s also to easy to see the 60 degree angle that helps to balance the engine and make the whole assembly a little shorter from top to bottom.
Notice that the exhaust manifolds are lined with stainless steel to keep the aluminum alloy from being heat worked over the life of the engine. That’s reliability, folks. Kudos to Trollhattan.