Destined as a common sight...
Destined as a common sight Mustang bolt-on, the Boss 302 intake manifold instantly announces the RoadRunner engine. Powerful as it is handsome, this race engine with license plates should stand as the pinnacle of naturally aspirated 5.0-liter Ford development for ages. Only with prohibitively expensive electronic engine management controls and higher rpm—or supercharging—could Ford substantially better this one.
Imagine you are a Ford engineer and you've been hammering for months on the new 5.0-liter Coyote engine for the '11 Mustang GT. Management ordained that the new V-8 must make 400 hp, the job has to be done in a third less time than normal, costs are limited because this is a high-volume engine for the populist Mustang GT, and you and your team have been working overtime coaxing all the power and efficiency possible from the new design.
Then management tells you to also create a special version of your new engine that makes at least 25 to 30 additional horsepower for the upcoming Boss 302. And hurry it up!
Would you feel a little overwhelmed?
Thankfully the Coyote team didn't mentally run off a butte because most of them segued into the RoadRunner team--what's faster than a Coyote?--to produce the 444hp Coyote derivative that powers the scintillating new Boss 302.
Furthermore, their compatriots in Vehicle Dynamics logged endless hours at the test track developing aggressive new suspension and steering packages, the calibrators worked the engine management to its limits, and the folks over at Ford Racing demanded to go professional racing with the new engine a year before customers could buy it!
That, in a lug nut, was how the Boss 302 came into the world.
This is an inside look at the process and resulting hardware. As with our major story on the Coyote 5.0 in the March 2010 issue, this in-depth look at the Boss 302 development was possible only with the extensive cooperation of the engineering teams that developed the Boss 302, an indulgence we at 5.0 Mustangs & Super Fords gratefully acknowledge.
Fundamentally the RoadRunner engine is an extension of the Coyote. By early 2009, the Coyote was prototyping, and as Ford V-8 Engine Programs Manager Mike Harrison noted, the Coyote "really had people's juices flowing, really had people interested in putting a Boss 302 program together."
So, while the Coyote had a head start, the RoadRunner's race had just begun. The idea was to extend the already state-of-the-art, not-yet-released '11 Mustang GT into a world-beating performance car channeled from the sharpest performing Mustang of all time, the legendary Boss 302. That meant the best road-holding possible, combined with an engine that lived for the lower right corner of the tach. For a performance target, Ford picked the BMW M3.
Mike explains how it got underway: "Jim Farley, who's a big Mustang nut, started pushing on the PD [product development] team and the marketing teams and the management to really start thinking about doing a Boss 302."
Tim Vaughn, the RoadRunner’s...
Tim Vaughn, the RoadRunner’s lead program engineer, is the go-to person for the Boss 302 engine. His supervisory duties are focused on the RoadRunner and he oversees every detail of the engine. He also was our personal guide for this Boss 302 story, a duty he discharged expertly, but one we’re sure he’s glad to have behind him.
The Boss 302’s RoadRunner...
The Boss 302’s RoadRunner 5.0-liter V-8 may be tuned to 89 hp per liter or 1.47 hp to cubic inch for traditionalists, and it’s offered only in a specialty car, but that doesn’t mean it didn’t have to pass all of Ford’s incredibly difficult durability standards. We think we’re going to have a really good time trying to wear this one out.
Mike Harrison is responsible...
Mike Harrison is responsible for all of Ford’s larger than 2.0-liter gasoline engines, which makes him a busy man. The boss of bosses on the RoadRunner team, just as he was for Coyote, Mike clearly enjoys the challenges of building the highest performance engines possible. A road racer and longtime Ford employee, he appreciates the nuances and legacies of the nameplates he’s privileged to develop.
"We were still in shellshock from having to deliver 400 hp out of the base 5.0 liter, so we weren't quite sure at that stage of what the performance targets should be, so they just kind of did a historical look back at the old Boss 302, and obviously it was naturally aspirated. It was a bit of a parts-bin engine--right?--and it was put together by a bunch of guys who were racers... ," Mike added. "And we kind of approached it in the same way. The team that we engaged to do the planning work and then execute it were all guys that were into performance. Even the base 5.0-liter guys--but even more so with the Boss 302 guys--were into racing Mustangs and that sort of thing."
"I talked to some of the Roush guys, [including] Bob Corn," Mike continued. "He was one of the original Roush guys. He worked for Ford as an engineer back in the day, back in the late '60s, early '70s [1962-1981--Ed.], and he was one of the people that was involved in the original Boss 302. I've had an on-going dialogue with him because, you know, he's a neat guy and I just love talking to him about the old stuff."