Turbos In Motorsport

[CRed05]

Brush up on your turbo history

 

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It’s difficult to believe that it is over 20 years since turbos dominated all forms of motor sport. From the muddy world of rallying and via the sterile arena of Formula 1 to sports prototype racing, the only way you were guaranteed a win was by having a massive turbo and a driver with equally large cajones and the talent to drive around the lag.

 

But the origins of the turbo in motor sport go back much further than their high-water mark of the 1970s and ’80s. The Halford Special, Frank Halford’s amazing creation, was arguably the first of its kind. Like most pioneering technology, it wasn’t a complete success, and it wouldn’t be until 1952 when Fred Agabashian took his turbodiesel-powered Diesel Cummins Special to pole position at the Indianapolis 500 that forced induction looked a viable proposition for motor sport competitiveness.

 

In 1966 Offenhauser’s turbo engines made a splash at Indianapolis, finishing in the top six. Overall victory then followed in 1968 when their original turbos were replaced by Garrett AiResearch items. By 1973, unencumbered by the boost limits that would follow, the Offenhauser peaked at over 1000bhp, but the engine, which had its roots in the ’30s, had already been surpassed by the Cosworth DFX.

 

The USA motor sport scene very much led the way in turbo technology. When Porsche decided to go down the forced-induction route, it focused on the North American Can-Am Challenge. In 1972

a turbocharged 850bhp Porsche 917/10 entered by Penske Racing won the 1972 series with George Follmer at the wheel. The following year the 917/30 – the ultimate evolution of the breed – sported revised aerodynamics and longer wheelbase. More importantly, it was powered by a 5.4-litre V12 that could be boosted to over 1500bhp.

 

Once again the 917 proved gloriously unbeatable, and with Mark Donohue driving it steamrollered the 1973 Championship, winning all but one race. However, the 917’s time was nearly at an end, and in the aftermath of the ’73 energy crisis and following a series of savage accidents in Can-Am, the SCCA introduced a 3mpg (US) formula that the 917 couldn’t hope to meet in turbocharged form.

 

But the world quickly recovered from the energy crisis, and the focus of turbo development moved from the USA to Europe, and more specifically Le Mans. In 1976 the turbocharged 936 made its debut. The Group 6 car was built for the World Sportscar Championship as well as Le Mans, and it hit the ground running, taking a debut victory at La Sarthe with Jacky Ickx and Gijs van Lennep at the wheel.

 

The Porsche 936 was a more realistic proposition to drive than the ultimate-boost 917/30, and its flat-six air-cooled engine developed 540bhp. By this time the rule makers had concluded that turbos should have an equivalency factor of 1.4, or in other words Porsche’s 2140cc engine would equate to 3000cc of normally aspirated power. As we would subsequently see in Formula 1, this was nonsense.

 

The 936 went on to dominate Le Mans, with Jacky Ickx adding 1977 and ’81 to his tally of victories, and these were the golden years for the turbo at La Sarthe. In 1978 the Alpine-Renault A442B took the win, while the next year saw customer Porsche 935s take the top four slots. Turbos would continue to set the pace at Le Mans until 1988.

 

Once Renault had scored its longed-for victory at Le Mans, it was free to concentrate its efforts on Formula 1 and rallying. Alpine had a wealth of forced-induction experience, and was actually the first company to win an international rally with a turbo in 1972, when Jean-Luc Thérier finished first in the Critérium des Cévennes in his modified A110. But Renault’s real dream was to take its turbo to the top of the tree in Formula 1 and, although the debut of the RS01 at Silverstone in 1977 was less than glorious, it was clear to seasoned observers that it could be the beginning of something great.

 

Through 1978 and 1979 the Renault earned a reputation for being fast but fragile, and a series of blow-ups earned its cars the nickname ‘yellow teapot’. But at the company’s home race at Dijon in ’79 the new RS10 held together to make it to the finish, and Jean-Pierre Jabouille scored the first turbo win in F1. That was backed up by a third place by René Arnoux, who enjoyed a thrilling final couple of wheel-banging laps with Ferrari driver Gilles Villeneuve.

 

By 1980 the Formula 1 turbo era was well and truly underway and, although Cosworth DFV-powered cars would continue to take the Championship until ’82, it was only a matter of time until they would be swamped by the growing ranks of the forced-induction teams. Ultimately, reliability issues continued to plague Renault, and its star driver Alain Prost narrowly missed taking the Championship in 1981, ’82 and ’83.

 

Turbos really only came of age in F1 when the engine manufacturers formed allegiances with existing teams: BMW went with Brabham, and won the ’83 Drivers’ Championship; Porsche teamed up with McLaren (although the British team paid for the engines and badged them TAG in tribute to one of its biggest sponsors, winning the Championships in 1984, ’85 and ’86); Renault allied with Lotus; and Honda chose Williams, taking Championship glory in 1987. Between them, they dominated F1’s most spectacular era.

 

The cars were hugely fast and, as the engine builders upped boost, they were able to produce qualifying-only ‘grenade engines’ capable of delivering upwards of 1500bhp for a couple of laps before melting down. It was a high-budget, high-glamour time that ushered in the modern era of big-business F1 – and anyone who witnessed Keke Rosberg’s amazing 160mph qualifying lap of Silverstone, or Ayrton Senna’s JPS-Lotus at the ragged edge during qualifying and being followed by a storm of sparks, will never forget it.

 

But just like Can-Am and Indianapolis over a decade before, the turbo’s huge power and performance would prove its undoing. The FIA decided that turbochargers were making the sport too dangerous and expensive, and in 1987 capped boost levels by forcing the fitment of 3.5-bar pop-off valves for all teams. In 1988 that was further limited to 1.5 bar in the hope of making the Cosworth DFV-powered teams more competitive, but in the end the McLaren-Honda turbo MP4/4 took 15 wins in 16 races. It was a fantastic last hurrah for turbos in a sport that banned them from 1989.

 

Still, at least F1 largely escaped tragedy, aside from Elio de Angelis’ horrible testing accident in his Brabham-BMW in 1985. Multiple fatalities would see the book closed on Group B rallying after what is still regarded by many fans as the sport’s most scintillating years.

 

Renault was once again a pioneer, unveiling its mid-engined 5 Turbo in 1978, and was soon up to speed, with works driver Jean Ragnotti taking victory in the 1981 Monte Carlo Rally. However, an unlikely upstart from Germany soon overshadowed La Regie’s achievements.

 

But then, the Audi quattro had hardly been expected by anyone. An almost unnoticed change in the sport’s regulations in 1979 allowed four-wheel-drive cars to go rallying. Although the common wisdom was that it was for the benefit of long-distance events, such as the Paris-Dakar (which a Range Rover won in 1979), Audi saw the potential benefits across the board. In spring 1981 the quattro arrived in Group 4 rallying and soon proved a force to be reckoned with, even if it had reliability problems at first.

Hannu Mikkola scored the quattro’s first win at the Swedish Rally, and the delightful Mich�le Mouton followed that up with victory in San Remo. From 1982 the German team proved nigh-on unbeatable and, although its success had as much to do with four-wheel drive as with its 300bhp five-cylinder turbo, it was clear that if anyone was going to topple Audi, they would need both.

 

Lancia’s pretty 037 proved this. The supercharged, mid-engined silhouette racer took the manufacturers’ title in 1983 but it wasn’t capable enough to win in mixed conditions. However, the machine, conceived for Group B, was sufficiently potent that Paul Fr�re foresaw problems for the new formula: ‘There is nothing to stop cars with 500bhp from racing on public roads between walls of spectators… until a very big accident happens and puts an end to the whole of rallysport,’ he commented at the car’s launch in 1982.

 

Four years on, his prediction was proved correct. The Audi Sport quattro in S1 form was putting out 600bhp, and was closely followed by the Ford RS200, Lancia Delta S4 and Peugeot 205T16. All looked as quick as F1 cars and bore no resemblance to their production counterparts. These Group B cars were alarmingly fast and were adored by fans, who wanted to get as close to the cars as possible – regardless of the danger.

 

At the Lagoa Azul stage of the Portuguese Rally, Joaquim Santos crested a rise to find the road blocked with spectators, and lost control of his Ford RS200 while trying to avoid the crowd. He failed, and killed three people. This was followed by disaster at the Tour de Corse, where Lancia’s Henri Toivonen flew off the unguarded edge of a left-hand bend and plunged into a steep wooded hillside. The car caught fire, and both Toivonen and his co-driver Sergio Cresto were killed. The combination of both accidents pushed the FIA into banning Group B from the end of the season.

 

It’s clear that the turbocharger revolutionised every form of motor sport that it graced. For F1 and rallying, it enabled major manufacturers to compete against the specialists (such as Cosworth), and cross-fertilise track and road technology. But that saw the arrival of huge budgets, big business and massive manufacturer-sanctioned operations that opened a huge gap between privateers and the factory teams. The glamour and big-bucks that followed the turbo into motor sport remain to this day.

http://www.classicandperformancecar.com/features/octane_features/254353/turbos_in_motor_sport.html

[Fubar231]

Great read