The Blue Oval is leaving no Stang untweaked for 2011, now announcing significant updates to the Shelby GT500 to go along with the already revealed 5.0-liter Mustang GT and base 3.7-liter V-6 cars. The most important alteration to the Shelby is a switch in engine-block material, tossing the old cast-iron block for a version of the all-aluminum lower end that was originally developed for the Ford GT. A larger intercooler and a revised exhaust bump power by 10 hp to 550, while torque stands pat at 510 lb-ft.
The aluminum-based supercharged 5.4-liter engine saves 102 pounds compared to the outgoing one. A process called Plasma-Transferred Wire Arc (PTWA) is being used to line the cylinders; a steel wire is melted and sprayed onto the cylinder walls, which are then machined. Along with the obvious weight savings over the cast-iron liners from the Ford GT’s version of the engine, the process is also said to improve heat transfer and reduce friction. The engine sports blue valve covers and a bright-silver supercharger similar to those of the GT.
Underbody aero tweaks and the weight reduction help improve fuel economy by 1 mpg each in the city and highway cycles, to 15 and 23 mpg, respectively, and the improved economy means the GT500 is no longer subject to a gas-guzzler tax. Don’t like the weight savings? You can pile pounds back on with the newly available glass-roof option for 2011 GT500 coupes.
A change from hydraulic power steering to an electric setup is also cited as reducing fuel consumption. Ford promises more steering feel, but we’re somewhat skeptical, as “feel” and “electric steering” aren’t generally compatible.
In addition to the new engine, the 2011 GT500 convertible gets structural stiffening that Ford engineers say allowed them to retune the suspension to be more aggressive. Additional gusseting, a stiffer crossmember and A-pillar, and an underbody front Z-brace are aimed at quelling body shivers, and Ford is claiming a 48-percent reduction in cowl shake. Convertibles also now get the coupe’s 19-inch wheels as standard. The 2010 GT500 droptop was a floppy, flexy hot mess—we loved it anyway—so we welcome the changes.
Thanks to: Car and Driver