Porsche 911 GT3 CAR review

Here come the high-performance 911's

Oh yes. Two years into the life of 997 generation, the Turbo and GT3 are bearing down on us. The Turbo - 480bhp, four-wheel drive, £98k - is on sale now. The GT3 - 409bhp, rear-drive - arrives at UK dealers on 26 August. Which one to choose? Handicapped by only two driven wheels, a 70bhp deficit and a conventional clutch, the naturally aspirated GT3 takes 4.1sec - 0.4sec longer than the Turbo - to hit 62mph. Although it may be a tad less explosive off the mark than the point and squirt Turbo, the GT3 is sharper and less forgiving. It's born for the track, but is perfectly usable on the road.

What have they done to the 911's classic boxer six?

By taking weight out of the pistons, the conrods and the crankshaft, the engineers could raise the red line from 8200 to 8400rpm. They've also increased the compression ratio, improved the cylinder head cooling, fitted double valve springs and featherweight tappets, plus a stepless camshaft adjustment device and a new intake manifold with three resonance chambers. Below 5400rpm, only the smallest breathing apparatus is on duty. Between 5400 and 6350rpm, a flap opens and allows extra air to circulate to boost the torque flow. Above 6350rpm, the entire manifold takes deep breaths of oxygen, generating maximum torque and power. There's also a free-flow exhaust with two-stage silencers. When fully open, they reduce the back pressure under trailing throttle by eight percent.