The 996 GT3 took Motorsport Porsche 911s in a completely new direction. More than 20 years on, both the Gen1 and Gen2 are highly sought after, so here’s everything you need to know…

Written by Kieron Fennelly

PORSCHE INDEX

HISTORY & TECH

With the advent of the 996, Porsche decided to abandon GT2 racing and focus on GT3. The cars would be less expensive to build and expand the company’s opportunities to race 911s in championship series in front of a much wider public.

Experiments with a prototype GT2 had also shown that even with 600hp, the turbocharged 911 would no longer be fast enough to beat GT2 competitors. Limitations of the M96 lubrication system (the engine fitted in the Carrera) meant that the new GT3 would require a bespoke unit.

The first GT3 was revealed in 1999 – a limited production run to qualify the race credentials of the 996. It differed from its air-cooled RS forebears: in addition to a specific engine, it used a heavier chassis, the more rigid shell of the Carrera 4 and was 40kg heavier than a stock 996 C2. Production realities meant that there was minimal scope in 1999 to make the GT3 lighter.

Despite its relatively impoverished state, Porsche didn’t stint on an engine that’s become known as the ‘Mezger’, even though Hans had retired in 1993 and had nothing to do with it. The credit is due to Herbert Ampferer, the long-serving mechanical engineer whose main claim to fame was the flat six that powered the Le Mans-winning GT1, a hybrid design with a fluid-cooled head.

 Herbert returned to this idea, taking the aluminium bloc of the 964/993 and grafting a specific water-cooled 24-valve head on to it, with the capacity increased from the GT1’s 3.2 to 3.6 litres. This was an expensive unit to build and even now the specification is impressive. The forged steel crankshaft had plasma-nitrided surfaces and titanium connecting rods that operated aluminium pistons in Nikasil bores. The head had a separate casing carrying the camshafts and tappets made from aluminium alloy, while the head itself used a special heatresistant alloy with copper, zinc and trace elements of antimony, cobalt and zirconium.