Ignition And Electronics
Coyotes in the 2011 Mustang use the Copperhead version of Ford's electronic engine control system. Jeff Seaman, the lead calibrator on the Coyote/Mustang project, ran us through the system's amazing highlights.
Copperhead is considerably more complex than previous EECs. It has to be with the TiVCT, but we didn't think 15 different tables would have cam timing input, but they do. Copperhead also integrates the new six-speed transmissions and engine into one speedier controller, so there's another layer of complexity.
Other changes are the addition of One Touch Start-the ignition key only needs a moment in the "start" position and the computer does the rest-as well as aggressive decel fuel shutoff and torque-based decel. The latter two shut off the fuel more often and sooner than previous EECs while coasting, on long downhills, and even during mid-shifts with the new six-speed manual transmission.
The 2011 Mustang also features a new digital mass air meter and universal exhaust gas oxygen sensors, which report a numerical air/fuel ratio-to something like the fourth decimal point-to the EEC. Previous systems weren't much more than rich/lean indicators.
Jeff reports that calibrating the 2011 Mustang took from April 2008 to November 2009. When he started, the car wouldn't start; when he finished, it was perfectly driveable, a job that took him to Arizona in the summer, Canada in the winter, and the heights of Colorado. The challenges of tuning the Coyote centered on its huge airflow. At low rpm, the engine is touchy because the combustion chamber has no tumble or swirl, so lighting the lean mixtures in that environment take careful throttle, fuel, and spark control. The precise sensors also pick up things such as the cams torquing out of shape, requiring compensation at high rpm.
The Coyote's tubular headers were a real challenge for cold starts, so Jeff had to use all his knowledge to get them to pass emissions. And then there was everything over 6,000 rpm, a range where Ford calibrators simply haven't gone before. Maintaining precise control up to the Coyote's 7,000-rpm redline was trying. Team members said if it had been any calibrator other than Jeff-a rabid enthusiast himself-they might have been told to limit the new Mustang's rpm and call it a day. We're lucky so many dedicated enthusiasts were on the Coyote team.
With that good fortune in mind, we must thank the Coyote team for reinventing the 5.0-liter engine back to Ford in a new form better than we could have imagined. So prepare to enjoy the second coming of the 5.0 revolution-the wait is nearly over.