Tom Wilson
March 2, 2003

Listen carefully to the buzz about what the '03 Cobra can do--that background noise you hear is the sound of tuners hard at work. Perhaps most animated of these is Jim Bell at Kenne Bell, thanks to the '03 Cobra's Eaton-built Roots-type supercharger. Jim has been eager to strut his stuff--all over the Eaton/Roots competition if at all possible--and what better vehicle for his agenda than the new Cobra? Obviously the car is factory-engineered for blower power, and all Jim has to do is take off the stock Roots-type blower and install his own supercharger along with the necessary supporting pieces. Luckily for everyone, after months of pleading on our parts, we were invited along for what proved to be a screaming dyno thrash--one of the highest-powered bolt-on tests we've ever experienced.

138_0303_01z 2003_ford_mustang_cobra Left_front_view
Horse Sense: History might show the '03 Cobra as the car that finally made the 5.0 Mustang obsolete. Its Four-Valve is the first modular engine to demonstrate the breathing and power beyond what the pushrod small-block is reasonably capable of.

In the following pages is a huge but condensed mass of data on what the stock '03 Cobra is capable of and how the Kenne Bell supercharger was engineered onto it to form a 600hp rocket. Besides highlighting the impressive airflow capacities of the Kenne Bell supercharger, the story illustrates the Cobra's electronic sophistication and hints at the changing state of performance tuning in general.

The Car
To test an '03 Cobra, you have to have an '03 Cobra. Normally Kenne Bell simply buys the car or truck needed, but this time, Randy Kramer provided the all-important subject. He was willing to take his chances on the dyno in exchange for the latest in horsepower. The spanking-new yellow Cobra had all of 904 miles on the odometer when we started, and more than 950 when we ended. Imagine, almost 50 miles of supercharged, all-out acceleration. And if you're wondering how a guy could go without his new Cobra for so long, it's because Randy is a cruise-ship captain, and while he's out to sea, he can't drive his Cobra.