2015 Ford Super Duty Power Stroke Diesel Gets Distinctive Cobra Head Downpipe

For the 2015 model year, the F-250, F-350 and the F-450 Super Duty trucks equipped with the 6.7-liter V8 Power Stroke oil burner boast with best-in-class 440 horsepower and 860 lb-ft (1,166 Nm) of torque. That's 40 hp and 80 lb-ft (81 Nm) more than the 2014 Ford Super Duty with the Power Stroke turbo diesel V8.
2015 Ford Super Duty Power Stroke Diesel Gets Distinctive Cobra Head Downpipe 1 photo
Photo: Ford
The competition stacks up as follows: the 2015 Chevrolet Silverado HD and sister model GMC Sierra HD benefit from a 6.6-liter Duramax with 397 horsepower and 765 lb-ft (1,037 Nm) on tap, while the Ram 3500 heavy-duty makes do with a 6.7-liter Cummins rated 385 hp and 850 lb-ft (1,152 Nm).

According to the Blue Oval, the second iteration of the Power Stroke motor breathes easier than before thanks to a cobra head downpipe like the one pictured above. Another highlight feature is the so-called reverse-flow layout that places the exhaust inside the mill's V-shape, while the air intake is positioned on the outside of the V. This advanced design shortens the airflow from the exhaust to the turbocharger, which is key to providing torque on demand.

And that cobra head downpipe design? Well, its job is to get the hot exhaust gases from the turbocharger out with as less obstruction to the exhaust flow as possible, which aids with power delivery. The cobra head design acts like a widened, banked turn, allowing exhaust gases to flow smoothly through the 90 degree turn from the engine to the aftertreatment system and reduce backpressure. By reducing pumping losses, the cobra heat downpipe generates greater torque.

“Fluid dynamics allowed us to precisely tune the curvature and width of the pipe to optimize exhaust gas flow,” said Robert Wade, engine air path technical leader. “It turns out that a downpipe shaped like a cobra head is the ideal design for air flow and breathability, which we validated through thousands of miles of durability testing.”
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About the author: Mircea Panait
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After a 1:43 scale model of a Ferrari 250 GTO sparked Mircea's interest for cars when he was a kid, an early internship at Top Gear sealed his career path. He's most interested in muscle cars and American trucks, but he takes a passing interest in quirky kei cars as well.
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