New PDK double clutch transmission turns the Porsche Carrera 4 into a flexible flier -- switching from an all-wheel drive to a rear wheel drive for some fun on the track.

Our colleagues at who took the new 997 for a few spins around the block at the Miller Motorsports Park have also revealed a neat trick told to them by Porsche engineers -- a sort of hidden feature of this new PDK transmission. By pulling up on the hand brake just one notch it's not the parking brake that comes on but what this Porsche actually does is disengage the front axle. Thereby turning the 997 (with a wink and nod) into a rear-wheel drive doughnut maker.

The seven-speed twin-clutch PDK will be featured in the new Porsche 997, or the Carrera 4, along with new direct-injection engines that provide a lot more torque in the lower rpm range.

What is different about this gear box is the exceptionally quick changes it allows. What also sets the PDK apart are its 3 different shift-modes -- Normal, Sport and Sport Plus. You can have a look at the video to see what the Sport Plus does for this Porsche.