2007 Ford Mustang GT

Horse Sense: Unfortunately, we can't always do these stories on our own cars, but we often rely on the kindness of others. Fortunately, Larry H. Miller Ford allowed us to borrow this 3d Carbon-equipped GT for our testing.

In today's performance world, a Mustang owner has a wealth of performance upgrade options from which to choose. When it comes to power adders, nitrous, superchargers, and turbos are all on the menu. To further complicate things, there are centrifugal superchargers and positive-displacement blowers that offer rpm-swelling power or instant boost, respectively.

If you're a fan of beltdriven power adders, there's another new option coming to light. The Rotrex blower is a centrifugal supercharger that basically uses the intake side of a turbo to produce boost and is turned by a unique traction-drive system. The traction-drive planetary is based on the same theory employed in an automatic transmission.

The Rotrex traction drive setup ranges from 13:1 on its smaller units to 7.5:1 on its largest unit. This produces impeller speeds of more than 200,000 rpm, while the largest unit still spins at 90,000 rpm. Since the supercharger spins so fast, the unit can be much smaller than other centrifugal superchargers and still produce the same amount of boost. The planetary/traction system requires less horsepower to turn than a conventional centrifugal blower and much less than the Roots-style/twin-screw blowers.

The technology behind the Rotrex blower has been around for years. Forced Air Performance is a new Danish company that has produced superchargers for several OEMs, including the Koenigsegg CCXR, dubbed the fastest production car in the world. Forced Air Performance is a spin-off from the parent company Mountain Performance. MPI produces supercharger kits for snowmobiles and side-by-sides.

"We've had great success with our kits using the Rotrex blower on off-road applications," says Forced Air Performance CEO Mac Randolph. "We chose the Mustang for our first automotive kit because almost every supercharger manufacturer makes a kit for this vehicle, and we want to show off our technology. This will be an excellent opportunity to expand our business into the musclecar market."

After hearing about the Forced Air Performance kit, we were immediately curious as to how it would fit on the car, the type of performance that the Rotrex supercharger could produce, and above all, the driveability. We took a trip to the Forced Air Performance facility in Draper, Utah, to witness the installation of the company's kit on an '07 Mustang GT.