After winning the legendary Pikes Peak hill climbing event with his own team in June, Romain Dumas took on another challenge this summer. The French driver began building a Porsche especially developed for the FIA RGT class. With this unique car, based on the Porsche 911 GT3 RS 4,0l, Romain hopes to take part in the Rallye de France-Alsace, 11th round of the World Rally Championship (WRC), and the Tour de Corse, European Rally Championship finale (ERC).

The Porsche 911 Turbo is celebrating its 40th anniversary in 2014. Hans Mezger, an engine expert and one of the Turbo’s founding fathers, took the occasion to journey from the past to the present—with two charged-up companions.

The sports-oriented gentleman likes checkered upholstery. The light-green leather is a perfect example, framing not only the sports seats. The radio has an integrated cassette deck. A long thin gearshift emerges from the center console. You can't miss the “H” on its ****—with gears one, two, three, and four—to make sure drivers know what comes next.

But shifting remains a complex task. Despite the little diagram, drivers have to not only find the right slot, but also feel it. To accelerate from second gear (bottom left) to third (upper right), you've got to pay attention to the signals traveling from the palm of your right hand to your brain. Light resistance will require a gentle change of course. It’s what we might call a sensitive approach, even for Hans Mezger, whom the industry press once christened the “Engine Pope” and the “father of all Porsche Turbo engines.” He knows the inner workings of the car like no one else, but before this fortieth anniversary tour he hadn't driven the museum piece in years.



Checkered history: Hans Mezger at the wheel of a 911 Turbo 3.0, built in 1976.

A first-generation Porsche 911 Turbo, built in 1976. It has an air-cooled boxer engine with six cylinders, turbo-*charging, a three-liter displacement, and 260 hp (191 kW) at 5,500 rpm. Torque of 253 lb.-ft. at 4,000 rpm. It needs 5.5 seconds to accelerate from 0 to 62 mph, and has a peak speed of more than 155 mph. Its fuel consumption (converted to the current New European Driving Cycle – NEDC) translates to 15.7 mpg. A timeless beauty in oak green, with a drive system that has always been the measure of all things and is once again expected to enjoy a great future.



Two kings of the road and “Engine Pope” Mezger at Castle Solitude near Stuttgart.

Mezger quickly becomes animated when talking about his Turbo, with which he has a lot in common. A fit man in his mid-eighties, he’s in the same good shape as the sports car. The fact that you need as much strength to steer as you do to shift and brake makes him excited. “This is what driving a car is really like,” he says with pleasure, and pushes down on the accelerator to the point that makes the Turbo into a Turbo. When the rev counter shows around 3,700 rpm, the turbocharger in the rear springs to life and vehemently presses more air into the combustion chambers.

That’s the moment when you're pressed back into the seat without warning and imagine Apollo 11 going into second-stage ignition. The Turbo takes off. “The Turbo gets going when other engines die down,” says Mezger with satisfaction. “And that just adds to the driving pleasure.” It’s a high-performance principle that, back then, took a little getting used to for most drivers. The Turbo—a sports car right from the pit lane.



Double charge: The 930 Turbo and 991 Turbo on the historical Solitude racetrack.

In the early 1970s, Porsche put fear into the hearts of its competitors in the popular Can-Am series. Naturally aspirated induction engines with seven- or eight-liter displacements had been setting the tone, but Porsche drove to win after win with the 917 and its considerably smaller displacement. The car’s turbo drive principle had actually been considered unsuitable for racing. Although no one disputed its higher output, they thought its response properties were inadequate. The turbine needed a lot of time and high rpm levels before it finally went into action.

Mezger, who is a qualified engineer, and his colleagues from the racing engine department discovered how to get around that. The turbocharger was made smaller, and the exhaust gases that were not used were channeled past the charger with the help of a bypass system. “All of the auxiliary systems that we applied already existed,” recalls Mezger. “They had just been used incorrectly and discarded. We rediscovered—and reinvented—them.”

The 917/30 Spyder of 1973 generated 1,200 hp (882 kW) with a 5.4-liter displacement. By changing the regulations, however, the Americans did away with the fearsome winner. The oil crisis came, and everyone including the FIA was suddenly thinking about fuel efficiency and production-based racing cars. Porsche had already made the decision to let series cars share in the Turbo’s success. In the fall of 1973, Porsche presented the first 911 Turbo at the Frankfurt International Motor Show (IAA). It was something of a premature birth, from which 400 road-going vehicles were to be produced as the basis for a racing car. In 1974 the first road-going 911 Turbo then appeared at the motor show in Paris.

The car was initially the object of internal controversy. The sales department thought it would never fly, considering it too sporty and also too pricey at 65,800 German marks (US$ 24,343 at the 1974 exchange rate with the West German currency)—and that during the oil crisis. To promote sales, the Turbo was fitted out as a high-end 911. But still the unsettling question remained: Would Porsche be stuck with the 400 cars?

In August 1975, Mezger and Ernst Fuhrmann, the board member in charge of technology, set off on a trip to Columbus, Ohio, to display the car. The journalists were shocked by its unusual driving properties at first—but then quickly became fans. “It was as if they had all been waiting for a car like that,” says Mezger. The automotive press touted the “mania on wheels,” and the 400 Turbos were quickly snapped up. More than 30,000 Turbos were sold until the end of the air-cooled 911 engines in the mid-1990s. “Without the 917, there probably never would have been a 911 Turbo,” he observes. The car from the pit lane had arrived.



911 Turbo 3.0

Change of scene: Mezger leaves the checkered upholstery for an all-leather black sports seat with fully electric eighteenway adjustment and a steering wheel with shift paddles. He’s now operating a water-cooled 3.8-liter boxer engine with direct fuel injection, VarioCam Plus (stepless inlet-side timing and lift), and bi-turbo-charging with variable turbine geometry (VTG). You'll search in vain for a shift-stick **** with an “H” on the sloping center console of the latest generation of the Porsche 911 Turbo S. The Turbo’s power can now be put to optimum use only via an automated seven-speed dual-clutch transmission. We're talking 560 hp (412 kW), and an average fuel consumption in the NEDC that translates to over 24 mpg.

The sports car drives commandingly down the country road with an engine that can wait patiently until its power is needed. “Downsizing,” remarks Mezger suddenly, while taking a gradual curve to the left. “The word didn't exist back then, but that’s exactly what we did when we got the best possible output from small engines with low fuel consumption.” During the Porsche Turbo’s stretch of victories on the racetrack, Mezger often gave talks at universities and to engineering associations. Everyone wanted to know more about the performance-boosting power of the underlying principle. He always pointed out that turbocharging is also superbly suited to reducing fuel consumption.

“No one was interested in that back then,” he notes. And when the Turbos slowly disappeared from racetracks in the late 1980s under the dictate of new regulations, he considered that a step backward. “The charger also dampened. That means the Turbos were quieter than other racing cars and had fewer emissions. It’s only now that everyone is talking about downsizing with Turbo support.”

Porsche has always been consistent in its thought and development, to this day keeping engines small and increasing their efficiency. The best example is this 911 Turbo S in the sure hands of Hans Mezger. “It has 560 horsepower,” he says and shakes his head. “Thirty years ago we were winning major races with this output. And today you can take it out on a Sunday drive. Compared to those days, all you have to do now is steer.” Time goes by, and the Turbo does more than endure: it flourishes.



991 Turbo S

Fuel efficiency: Turbo object lesson from the Formula One



Formula One driver Niki Lauda (left) and Hans Mezger at the racetrack in 1985.

Company founder Ferry Porsche was always clear: “We race in order to build the best sports cars for the road.” This alliance always served the Porsche 911 Turbo well, which owes its existence to the Porsche 917/30 Spyder. A perpetual winner in the Can-Am series, it was known to the Americans as the “German tank.” Even after its Can-Am career, the 917/30 with driver Mark Donohue at the wheel set a new world record for circuit courses in 1975 on the 2.65-mile high-speed oval in Talladega, Alabama, with an average speed of 221.1 mph.

But engine expert Hans Mezger had another favorite when it came to the fuel efficiency of Turbo engines, namely, the Formula One assembly that Porsche developed in the 1980s as a TAG Turbo for McLaren. Thanks to exhaust gas charging, its 1.5-liter V6 engine generated well over 800 hp (588 kW). The regulations limited gasoline consumption depending on the type of engine, which led to a dispute in Kyalami in South Africa in April of 1984. Niki Lauda and Alain Prost were out alone in front in their McLaren TAG Turbo, winning easily after 75 circuits and 191 miles. The rest of the field was lapped or left at the side with an empty tank. The competitors suspected fraud and lodged a protest, claiming that performance of this type could not have been possible. McLaren had to open up the tanks for inspection. Everything was in order. McLaren won world championship honors three times in a row with the Porsche Turbo.