In recent months, rumors have been rampant that the next generation of Ford’s Shelby GT500 Mustang would dump the existing 5.4-liter supercharged V8 in favor of a twin-turbo version of the new 5.0-liter Coyote V8 that debuts this spring. Unfortunately, in spite of earlier reports confirming the development, it appears that such an engine will not be installed in the GT500 any time soon. Mike Harrison, Ford’s chief engineer for the 5.0-liter and 6.2-liter V8 engines made it clear that the mooted engine is not part of the program for the Blue Oval bomber.Harrison explained that such a configuration would be almost impossible for Ford to engineer because the 5.0-liter already consumes virtually the entire engine compartment. There is evidently no room to mount the turbos on the outside of the block where the exhaust currently resides. One possibility would be to put the turbos in the valley of the block similar to the new 6.7-liter diesel or BMW’s 4.4-liter twin-turbo V8, but this creates a bunch of new problems as well. The heat generated by having the turbos up top would probably cause the paint on the hood to bubble and peel unless Ford could add some exotic and undoubtedly expensive heat shielding, which is unlikely to happen.
The other issue is that this configuration would really only work if the intake and exhaust flow were reversed, putting the exhaust in the valley. Without this change, the paths from the exhaust ports to the turbos would be too long, resulting in excess turbo lag and unacceptable performance. However, this would require a level of engineering investment for new heads that Ford is unlikely to make in such a low-volume program. Thus, we’ll have to be satisfied with the aluminum block 5.4 that is arriving later this year.