The most extreme 911 ever
The GT3 has more power, a bigger engine and several new electronic driver aids to boost performance over the outgoing model.
The engine has been upgraded from a 3.6-litre unit to a 3.8-litre, boosting power by 20bhp to 435bhp. Porsche says the extra capacity has helped to significantly improve mid-range pulling power.
As a result, the GT3 will travel from 0-62mph in 4.1 seconds, pass 99mph at 8.2 seconds and hit a top speed of 194mph.
The GT3 is now fitted with a stability management system, but both the traction control and stability control can be turned off.
A suspension management system is also fitted, which can be switched between Normal and Sport settings, with the latter firming up the ride.
Track driving is aided by a system that detects aggressive driving, responding by automatically stiffening up the engine mounts.
The GT3 rides on new lightweight, race-inspired wheels, which feature a quick-release centre locking nut.
Options include carbon-ceramic brakes and an electronic lift on the front axle, which adds 1.2 inches of ground clearance.
The Porsche 911 GT3 goes on sale in the autumn, with prices starting at £81,914.