5.0 Mustang & Super FordsCar Reviews
2011 Ford Mustang 302 - Inside The Boss
How a dedicated team brought forth the greatest Mustang ever built
"And so it totally worked because if I walked in and said, 'I want to go 7,750' from the beginning of the program, everyone would say, 'No way, not a chance.' But the intake is what sets where peak power is, so I gave them this ever-increasing reward for going higher and higher, and that's how it happened."
If you wondered where the RoadRunner got its legs, now you know.
Translating Adam's power peaks into hard plastic reality were David Born and Beth Anne Dalrymple, who did the hard work of designing the actual intake and pushing it on to production. Late in the program, David left the RoadRunner team for another assignment and was replaced by James Cummings, who actually shepherded the black eight-legged spider through manufacturing. Beth brought an especially potent background to the Boss intake design party. Her background is in CAD design, the nitty gritty of laying out and building intake manifolds. She also knows what it takes to get them compatible with the machinery and procedures in the manufacturing plant. It's said she's designed just about every intake manifold Ford has built in the last 20 years.
But now Beth works in CFD, computational flow dynamics, the Ouija-board computer modeling science of what the air is doing inside the intake. She took the lead on designing the Boss intake, taking it all the way from the fundamental "air core" through the final product. Her experience with all aspects of manifold production meant there were no missteps, but hundreds of computer iterations of the intake were run through Ford's giant computer lab to get the details as good as possible.
"The idea of the shape has been similar all along," Beth explained. "[The] standup runners... that didn't change. We knew we had some package issues--hood lines--to fit within, but that idea didn't change. It was all about getting the runner to be the best flowing runner, which Dave and I worked on quite a bit. And after that, we looked at the plenum and how good we could make that. ...There's a little nose in [the entry]... We worked quite a bit on that little nose, the entry."
What is critical about the entry to the Boss intake is it splits the incoming air into two major streams left and right. The "nose" is a bump just downstream of the throttle body on the intake floor. It's for packaging the carryover fuel rail, but it took careful shaping to correctly manage the incoming air. The runner entries and shapes consumed a tremendous amount of time and computational power. In the end, the runner entries molded into the floor of the plenum responded to radii much larger than what theory said, which was something of a surprise.
Another bit of work was packaging and shaping the runners. They twist from a vertical rectangle at their top to a horizontal rectangle at the bottom. David explained the labor and rewards of this runner challenge: "So we're trying to keep the [runner] areas relatively constant--that's important to us--and how that change in shape goes from this end to that end is important. So she [Beth] has some special software she uses to control that, and she picks sections along the way... We spent a bunch of time changing those sections, and in the end took one or two of them out, and let this proprietary software that we use to make the transition the way it thought was best. At one point we ended up picking up a horsepower and a half just allowing that shape to change. Overall the intake was worth 10 to 12 horsepower, so you get a horsepower and a half from just changing how you let this area develop from here to here over such a short distance--that was huge to us."