Porsche Index: 997.1 Turbo

The 997.1 was the last Turbo that could trace its origins to the original 930, and makes for a great-value buy today. Total 911 presents everything you need to know about it…

Your complete guide to the last Porsche Turbo with the famous ‘Mezger’ flat six

HISTORY AND TECH

The first-generation 997 inherited its engines from the 996. However, from the outset in 1999, for the first time since the original 930 the 911 Turbo did not use a blown version of the naturally aspirated 911 flat six, but what was almost a bespoke engine. Porsche’s engineers knew the M96 of the 996 would not be suitable for circuit racing as oil starvation occurred above lateral forces of 0.7g, speeds readily attained with competition tyres. Yet a production 911 that could not go racing was unthinkable. The Motorsport department thus developed a specific engine for GT3 competition. This was a hybrid unit which took the seven-bearing alloy crankcase of the 964-993 and used a water-cooled head which was derived from the 959 and the GT1. Making generous use of Nikasil, titanium and expensive aluminium alloys, Porsche could not hope to recover the cost of this engine through its GT3 programme, but realised the cost could be amortised by making this engine the basis of the forthcoming 996 Turbo. For the 997.1 Turbo, there were no fundamental changes to the engine design, but its compression ratio was further lowered to 9.0:1 to take into account Porsche’s new Variable Turbine Geometry (VTG). Clever software controls developed by Weissach allowed the turbine vanes to turn, akin to feathering an aircraft propeller, according to how much boost was called for as the 911 was accelerating. This more precise utilisation of turbocharger energy not only meant a wastegate was no longer required, but resulted in enormous extra boost, increasing the 997 Turbo’s power output from the 414bhp of its predecessor to 473bhp. VTG allowed an Overboost (via the optional Sport Chrono and limited to ten seconds) which momentarily pushed maximum torque from 620Nm to 679Nm. Cd remained at 0.31 and use of aluminium door panels and framework kept weight to 1,585kg, no greater than the 996. Like previous Turbos, the 997.1 used the stiffer C4 body, but handling dynamics were enhanced by a more sophisticated control system which simultaneously coordinated traction management (PTM) varying drive between the front and rear axles, damper settings (PASM) and the standard stability control (PSM). The cabin was almost indistinguishable from any other 997; full leather was standard, as was Porsche’s latest navigation software, but adaptive seats, Tiptronic, and even parking sensors were still extras.